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Ask the Alchemist #83

Can I just let my chocolate stir at 88 F for a few days in my tempering machine to temper it?

As it turns out, I was going to do a follow up to Ask the Alchemist #77 about tempering, and specifically address this.

Basically, what you should get out of this is that the melting point of a crystal (94 F for Type V) is not really related to its formation speed at all, except the formation rate is zero at the melting point, i.e nothing can form if it is melting. All other bets are off.

To explicitly answer your question, the purpose of reducing your chocolate to 28C/80F is to create 1-2% Type V crystals ‘in a reasonable amount of time’. At this point I have had my tempering machine (alchemist built) run for 2 weeks. Lots of tests. LOT AND LOTS of failures….and some success.

The short answer is that 72 hours at 88 F- 90 F will not form Type V crystals. So I was slightly off base with my answer above. With that bit of lab data in hand I sent searching technical papers and confirmed that. It was not even that they were forming slowly. X-ray crystallography (pictures at crystal resolution) showed zero formation at up to 2 weeks at various temperatures.

Why? I don’t have all the answers yet, but I have a hint.

It has to do with folding structures. The best analogy I can come up with (representative drawings are actually coming) is origami.

You make lots and lots of folds to get to a final shape. It just isn’t possible to do from A to D. You have to fold the paper along line A. Then turn and fold along B. Then this little unfold along C and finally a last manipulation, and there is D.

Cocoa butter, being a polymorph, is the same way. And in this case, it appears Type IV crystals are one of the intermediate steps, so without IV, formed when you go down to 80-82 F, you can’t get to V directly.

I know that does not give any real practical answers, but I hope it starts to shed a little light on the process, and fills in just a few of the ‘whys’.

Stay tuned for more on tempering….I have had some interesting successes. Now to see if they can reproduced. Have a look.

Click to Embiggen What’s so interesting? Just this. Those four cells were made from chocolate that was not classically tempered nor seeded with tempered chocolate……

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Tempering test

Calling all Novices, Apprentices and Alchemists that have tempering machines, available chocolate and would be willing to take part in a simple experiment for me.  The test is pretty simple, but will require a couple days of uninterupted use of the unit.Please write to me (don't post here) at alchemist (at) chocolatealchemy (dot) com.  Subject: Tempering test for details. Thanks.



PhD in Chocolate

I very rarely put this kind of thing up.  World news that does not relate directly or really even indirectly to making chocolate at home (at least on the short term), but this is too neat. Cambridge University of Cambridge is looking for a Studentship in Chocolate. The goal?  From what I can read, they was a new or modified state of temper that is higher than Type 5.  Something that can handle high heat, not melt and retain it's temper and appeal.  Nothing like being a nay sayer though.  From this line, " to remain solid and retain qualities sought by consumers when it is stored and sold in warm climates" it feels like a logic puzzle that have two sets of non-overlapping criteria.  Namely, it melts readily in your mouth (<98.6 F) but not in warm temperatures (> 100 F).  I guess as I write that, it is a bias for me to consider over 100 F was 'warm'.  If they define warm as 95 F, then it works if they can get a stable crystal form that melts between 95 F and 98 F.  I can't see how they can do it without additives...but I'm not a PhD either.

I wish them the best of luck.



Ask the Alchemist #79

How stable is chocolate tempered and non tempered? After removing finished chocolate from the melanger , can or should chocolate be tempered first or can it be put in ziplock bags straight from melanger ?

Welcome back for the continuation of our story. Before we continue, here is a photo of some fresh and month old raw nibs. The thing to note is the whitish edges on the older nibs.


(click to embiggen) This is my benchmark for fresh vs older in nibs. This is exactly the same nib (Ghana FT) but the one on the right was just cracked and winnowed and the previous one is about 30 days old. Now, if you have been paying attention, you will note that I said 1-2 years for raw nibs and here I am showing a difference at 30 days. True enough….and why you can’t always judge a book by it’s cover (goodness, I love analogy ). Sure, they look different, but the resulting chocolate, to my palette, is indistinguishable. It still takes a 1-2 years before you can taste the difference. On the other hand, roasted nibs don’t seem to change color this way, but I can taste the difference in a month or so. They do change color (after 4-6 months), but usually it is well after they have gone stale.Now let’s jump right into your next question.

I feel like a politician here. What do you mean by ‘stable’? Do you mean how long does it stay fresh? Or how long does it stay in the crystalline or non-crystalline structure it is in? Or do you mean how hard do you have to hit be before it detonates? Well, let’s get the easy one out of the way.

Chocolate, nor any of it’s components have any stressed or strained bonds. No triple bonds. No azo groups. No metal azides. Not even a little Hexanitrohexaazaisowurtzitane. In a word, chocolate, whether tempered or not tempered is 100% stable…in the sense that it won’t detonate or explode under any circumstance I can think of.

Great. We have that bit of fun out of the way. Technically, tempered chocolate is less stable than untempered chocolate. But here we are talking crystal structures, energies of enthalpy and the like. Suffice to say, because as it naturally occurs, tempered is less stable because it has a higher energy of enthalpy, and it converts to untempered spontaneous (if in liquid form without seed) because it is easier, (read lower energy). If I have not lost you there, great. If I have, just smile and nod and let’s move on because I don’t think it is really what you want to know.

By stable, I am going to assume you mean does tempered or untempered go stale faster or slower than the other. The answer to this is I think they are about the same, but I’m not sure, and even if they are not the same, other factors will play a great role. For this discussion, go for what is easiest (untempered) for storage and don’t sweat it. You don’t HAVE to temper it right from the melanger.

That brings us to liquor (i.e. cocoa mass, unrefined, unsweetened cocoa, etc) and chocolate. By far, except for unroasted beans, this is going to be your most stable form. And in the larger the volume the better.

To review, staling is oxidation. Solids don’t oxidize that easily. Think of rust. That is oxidation. The surface of iron rusts but it takes MUCH longer for rust to penetrate into a hunk of iron. There just isn’t anything moving to distribute oxygen. The amount of rust is proportional to the surface area. The exposed area more specifically. If you have a 1 lb block of iron and 1 lb of nails, the nails are going to have hundreds of times more rust because it they have hundreds of times the surface area. So the rule of thumb is whatever has the least surface area (exposed) will stale the slowest. That said, most people mold up chocolate after it is tempered. That means lots of pieces of chocolate (like nails) surface area compared to one bag of untempered chocolate. For the surface area reason the untempered chocolate should go stale slower than the tempered chocolate.

BUT…..wink….there are arguments that controlled aging ( of tempered chocolate is just another name for controlled staling. So maybe you want a little staling at the right time….See how clear this all is?

My recommendation is this. Keep it simple. Let chocolate making fit into your life. Relax and enjoy it. But plan a little.

  • Roast when you know you can let the beans rest a day to cool.
  • Winnow when you know you can make the chocolate within a week or so.
  • When your chocolate is done, bag it up (air tight, i.e. zero exposed surface area) in a ziplock bag until you are ready to temper.
  • When your chocolate is tempered and molded up…call it aging, not going stale.
  • And this is the most important

  • Eat and enjoy your chocolate you made with your own hands and don’t worry so much. It’s only chocolate (wink).



Ask the Alchemist #77

Hi! so i understand that when working with dark chocolate you have to melt it to 45-49 C. and then cool it to 28C. Then reheat it to 32C, to melt out all of the unstable crystals. But is it possible to just skip the middle step of cooling to 28C? What if i just melt the chocolate and cool it down to the working temp of 32C and then pour it into my molds? This way won’t I be maintaining a temp high enough to melt the unstable crystals while keeping the stable form 5 crystals? What after all is the purpose of cooling to 28C then? At what temp do stable form 5 crystals start to form after melting?

This is a really good question and one I have received over the years quite a bit. And I have to say it stumped me for a while. Really, it makes perfect sense…in theory, but it fails in practice…or does it?


So why does it not work? Let’s look at what you are trying to do, and what you are and are not doing if you don’t reduce the temperature to 28C/80F.

Solid chocolate is by definition 100% not liquid. I don’t say 100% crystallized because technically it can be amorphous or without crystal structure, or a mixture of amorphous and crystal structures. In totally untempered solid chocolate we can estimate that 20% is Type V and the rest are types I-IV (this probably actually isn’t true due a whole host of reasons (rates of crystallization in contaminated polymorphic system would sum it up) but close enough for the example). With that number in hand, we can see that we can have up to 20% Type V crystals when we bring the temperature down to ‘seed’ temperature, i.e. that point where the chocolate just starts to thicken a little. The cooling step of 28C/80F. In actuality, it is probably much less than 20%. Maybe 10-20% of that, the rest being Types III-IV (types I-II form much lower) and un-crystallized liquid chocolate. So, with a little rough math, that means there is probably 1-2% type V crystals.

Now, what I find terribly interesting about my ‘back of the envelope’ calculation is that that number is very close to the recommended amount of seed chocolate (i.e. 100% type V) you should add if you are tempering by seed. Why? I’m glad you asked. It comes down to a concept called nucleation. In layman’s terms you have to have a nucleus or SEED for the rest of the chocolate to form around and experience shows that for chocolate you need at least 1-2%. Below that and either the crystal formation is too slow, or there are too many places in the solidifying chocolate that are ‘un-seeded’ so other crystals start to form instead.

So, why does it not work to bring your chocolate to 32C/88F and then let it cool? Well, if you followed what I was saying above, it can only be because you don’t have enough Type V crystals. You are below the 1-2% threshold limit for proper Type V propagation. And that is because crystallization is heavily temperature and concentration dependent, and polymorphic crystallization is even MORE dependent on those two conditions. What that boils down to is that you are not giving it enough time at 32C/88F. (DISCLAIMER: I am totally making this next part up, but keep in mind I’ve many years as an organic chemist, so have a reasonably good gestalt feel for this kind of thing. And I am backing it up with the fact that we know that holding at 32C/88F doesn’t work.) In order to reach 1-2% type V at 32C/88F you may well have to keep it at that temperature for 24 hours. Or 48 hours. Or longer. Even if it was only 4 hours, that is quite a while if you want to temper NOW. And to make matters worse, generally speaking, crystallization is not a first order rate of reaction in regards to temperature. This means that if at one temperature (say 28C/80F) you are forming 0.1% Type V per minute, a couple of degrees warmer won’t reduce it just a little to 0.6% or 0.8% per minute, but will probably reduce 1-2 orders of magnitude, meaning just a couple degrees higher and you are down to 0.01 or 0.001% per minute…and you need to get to 1-2% and you want to raise it 5-10 degrees? You can see why it does not work.

Basically what you should get out of this is that the melting point of a crystal (94 F for Type V) is not really related to its formation speed at all, except the formation rate is zero at the melting point, i.e nothing can form if it is melting. All other bets are off.

To explicitly answer your question, the purpose of reducing your chocolate to 28C/80F is to create 1-2% Type V crystals ‘in a reasonable amount of time’.

One final science tidbit that I won’t (and can’t, I just don’t understand it well enough myself. Basically a variant of a variant of a Feynman quote "If you can't explain it to a six year old, you don't really understand it.") explain. It is in regard to your comments about stable and unstable forms. There is a general truism of polymorphic systems (i.e. compounds that form multiple crystal structures). It is that the LEAST stable forms are the forms that form first. So, Type V is the least stable. And really, this makes sense. If it were the most stable, we would not have to work so hard to form it and keep it. It would just happen…but it doesn’t, does it?

Class adjourned.

Go rest your brain and have some chocolate.

And keep those questions coming.

—– Submit your Questions to the Alchemist: question(youknowtoremovethisright?) —–



Ask the Alchemist #76

I have had some hit and miss tempering with the prototype temperer. It worked beautifully for my smaller test batches and only tempered half of the large batch I made last week. I have been looking at all the tempering methods you talk about on the website and contemplating trying it without the tempering machine. I know when I have done it at your house, we did hand tempering by using a double boiler and ice water bath. I would assume the same temperature parameters apply there as with the temperer: Get the chocolate down to 82 or so, then bring it up and hold it at 88-90.

I also read the tempering page on the site again and it discusses using marble and working the chocolate. Since i do not have a marble slab, this option is out.

Then I read your instructions on tempering in the santha using seed chocolate. That one is looking like something I want to try.

What do you recommend for me?

First off, everything you try without the tempering machine is just going to be harder. Even if it does not control the temperature right where you want it, you can use it to control the temperature manually and it stirs. That is basically it's benefit. So your assumption that the same temperature parameters apply are spot on.....except they are not absolutes. If you are a couple degrees too hot on either end, you can loose temper. So it might be than simple.

For the larger batch that only partly tempered, which half was it. The first or last half? Or was it peppered throughout?

About the only thing we know for sure is that you brought it down cool enough to form seed chocolate since some of it tempered.

If first, then I suspect you didn't turn the heat down and it over shot for the 2nd half and you lost temper.

Or it could also be handling technique.

If the 2nd half or mixed, then it could be handling technique.

What I mean by handling technique is over working the chocolate. Extra smoothing. Lots of dipping to fill one mold. And it sometimes gets worse near the end as the chocolate starts to get thicker. If you notice it getting thicker, then the chocolate is tempering (crystals are forming) and you have to raise the temperature a little to keep it fluid. It can sometimes be like walking a moving tight rope. Where at the beginning your working temperature was 87 F (for example) but by the end, it may be 90 F to keep it fluid enough to work with. Why can't you just have it at 90 F to start? Because the temperature is related to the amount of temper (i.e. the amount of type V crystals) in your chocolate. The more type V, the higher you can and need to go to keep it fluid. And you tell how much is there by viscosity. Basically, as it thickens, raise the heat to keep it in balance. You are destroying some of the type V, but that is ok. There is plenty, as noted by how thick it is. If you don't raise the temperature, then you have to 'work' the chocolate and you mess up the crystal structure, and you get bloomed chocolate.

Next. Marble. It isn't magic. It is often mentioned because it is non-porous, easy to clean and a good heat sink. I have used tile, granite, Corian and even just a clean counter. About the only thing really out would be wood or tile with grout. So anything that has those properties (glass? sure) will work.

As for working with the Melanger and seed, if you have a tempering machine, then in a way you are going backwards. A melanger is for when you don't have something that stirs slowly and mixes the chocolate (like a tempering machine) and for the sake of using something that you have on hand. The melanger has no other benefit, and has drawbacks. It runs pretty fast. The rollers get in the way. You have to add external heat. If the control on the tempering machine isn't working, then don't use it and add external heat and an external thermometer. Or better yet, use the tempering machine, use an external thermometer, verify what it is seeing on the display is what you are seeing from another thermometer, and if in doubt, use the external one and adjust your tempering machine settings accordingly. If your tempering machine says it is 89 F, but your external thermometer says it is 91 F, you can see the problem. Reduce your tempering machine temperature a degree or two (assuming it's smooth and has a low viscosity of course).

So what I suggest if finding out the cause of the hit and miss tempering. Stick with the tempering machine, and find the pattern as to where it is not working...then fix it. As I see it, it can only be a couple things. Either your chocolate is getting too hot, too thick or you are handling it too much....or some combination of those.



Ask the Alchemist #69

Chocolate molds, better ones anyway, are made with polycarbonate, which generally contains BPA or a related chemical. These chemicals have gotten a lot of press for mimicking hormones. I have seen some BPA free molds but they're still a rarity.

Does BPA enter the chocolate during molding? Is contact too brief? Temps too low? Or are we just turning a blind eye?

In short, the answer is we don’t know.

There is just no data out there so it leaves answering the question to speculation and my background in chemistry. In some places that is called ‘speculation’. Or an ‘educated guess’. Basically, I’m ‘theorizing’. But since I’m not giving concrete conclusions, it can at least be said that I am not ‘making sh!t up’ !

I am rather glad you didn’t get into asking my thoughts on whether BPA is a concern, but that is a real hot spot of contention. Regardless, there was some good data I was able to collect along the way.

BPA is the friendly abbreviation for Bisphenol A. Which is also a friendly name for it’s IUPAC name of 4,4'-(propane-2,2-diyl)diphenol. And thank goodness for standardization as its original name was either p,p'-isopropylidenebisphenol, or 2,2-bis(4-hydroxyphenyl)propane.

It has a solubility in water between 120 and 300 mg/L. It is freely soluble in oils, fats and organic solvents. Because of this later piece of data, it is theorized that the contamination to oily or fatty products (like fish in oil vs fish in water) would be higher, but I could not find one single piece of data to support that assersion….which means to me that people most likely are ‘making sh!t up’.

Part of the reason I say this is there is precious little data to support a direct link between solubility and leaching. They are two different animals as it were. Leaching in the most simplistic terms might be considered surface solubility. But only kind of. Solubility involves a solvent (let’s say water) surrounding and encapsulating the solute (the BPA). It requires the solvent to get between the molecular spaces of the solute in order for it to surround it and carry it off into solution. With leaching, it’s more a matter of what can the ‘solvent’ shake loose and carry away. Analogy time. You have dirt rubbed into your shirt. And the dirt here is powdered rock and sand but also clay and hummus. Stuff that isn’t soluble in water (the rock) and stuff that is soluble in water (the hummus). If you put that shirt in a bucket of water and don’t agitate it you will find that the water starts to color. The soluble hummus is being surrounded by water molecules and carried off. But the sand and rock stay imbedded. It takes agitation to shake them loose or ‘leach’ them from the shirt. Kind of make sense?

As for numbers to show leaching has little correlation to solubility, let’s look at that solubility of BAP vs what is found in two different ‘solvents’. Recall the solubility in water is 120-300 mg/L or ppm. That is the maximum that can go in. The levels found in water are 0.1-10 ug/L. The levels found in liquid baby formula were 0.8-11 ug/L. There are two things to notice here. The first is that the amount found is roughly 1/10000 the solubility level. Hundreds of parts per MILLION vs parts per BILLION. Next, to me, those two leaching values are basically identical. The ‘high’ fat formula had no noticeable effect on how much was leached. Now, please know, I am NOT saying oil won’t leach more…just that I can’t find any evidence of it. Which is a good thing for chocolate since it is 30-50% oil.

The next bit of good ‘evidence’ for chocolate comes from ‘modes of transmission’. We have looked at how BPA leaches into a liquid over time. But there are other ways for it to transfer. Solid to solid is another way. In the same study that liquid baby formula was looked at, they also examined powdered (high fat) baby formula in lined containers….and only found BPA in one of 14 of the samples. That’s good news. My suspicion why is because the container was rigid and the ‘solvent’ (being a solid) could not knock, brush or liberate any BPA from the surface of the lining (sort of like in a chocolate mold).

And this is kind of confirmed, or at least not contradicted by the fact that one of the highest forms of transfer was from thermal receipts that contain BPA. In this case, although both surfaces (the paper and your hand) are both solids, the contaminated surface was highly flexible so was able to ‘slough’ off BPA readily. Think again to our shirt example. It’s dirty. And so is a rigid baseball cap. If you pick up and handle both, which is going to get more dirt on your hands? Most likely the shirt. It gives, the dirt cracks, and readily falls onto and transfers to your hand. It has a reason to move because it’s being dislodged by physical means.

Temperature does play a role in leaching.  Higher temperatures (150-210 F) leach more (2-10x more) but chocolate is not molded anywhere near those temperatures.  Good for us. And one final note on leaching. It takes time. When I was in the lab we performed an extraction called a Toxic Characteristic Leaching Procedure (TCLP). In the procedure, we added what we wanted leached into a container with a leaching solution (not even called a solvent) and this was agitated (tumbled actually) for 24-30 HOURS. Which makes sense as the highest contamination is found in water bottles and canned foods where they sit for quite a while and are moved and agitated. My main point here is that time is a critical factor. In a few circumstances we did ‘instantaneous’ leaches for curious customers and found radically reduced leaching rates. Again on the order of 1/100 to 1/1000 times less.

So, here is what I see and could find in regards to BPA contamination and leaching.

  • Leaching is not directly related to solubility so oil vs water is does not matter.
  • Leaching is related to the surface of the material in question. Solid surfaces show much less contamination than highly flexible surfaces.
  • Leaching is related to time to some degree, with instantaneous leaching from solid/liquid boundaries being very low.
  • Leaching from one solid to another solid (powdered baby formula in a rigid container) is very low.
  • Leaching increases as temperature increases.

With all that in place, my gut feeling is that the contamination from polycarbonate molds to chocolate should be very low because:

  • The mold is rigid.
  • The chocolate although oil based does not increase transfer.
  • The time it is fluid is VERY low.
  • Chocolate is molded at 'cool' temperatures.
  • Solid/solid contact shows nearly no transfer potential.

Basically I can’t find any good reason that there should be hardly any transfer at all from polycarbonate molds to molded chocolate. But I want to re-iterate, I am just following a logic and data trail and we don’t know. To know for sure would take an actual analysis. Which honestly I am stunned has not happened and been published. Anyone?

So, to specifically answer your questions:

I don't know if BPA enters chocolate during molding, but evidence indicates probably very little

Yes the contact is too brief and of the 'wrong' type.

Yes the low temperature helps keep it to a minimum No, at this point now, we are not turning a blind eye...but maybe someone should test. That’s my take.



Ask the Alchemist #35

I purchased a 1 oz hobby grade bar mold from your establishment. I have been pleased with the results (good shine and crisp snap) in general, but I am a bit puzzled by a spot in the middle of each bar that has a slightly different sheen where the bar contacts the mold. I'm guessing the center is the slowest area to cool. Is there something I can do to avoid the variation in sheen?

This is the difference in theory and practice. In theory, there should be no difference in hobby molds and professional molds, but in practice there is a difference.

This is a result of it being a hobby mold. A few words about molds. Hobby molds are about 1/3 the thickness of professional molds. First off, the mold is less expensive and great while your chocolate making is, well, a hobby. Funny that. Next, the thinner polycarbonate allows the mold to flex and bend. Over time, these molds will crack along the edges and simply show harder wear. Finally, this flex allows the chocolate to warp the mold as it contracts during the temper. Now, a few more words about tempering and contracting. As I’ve talked about quite a bit, tempering is the selective crystallization of cocoa butter into Type V crystals. In know, I know. Wah, wah wah, wah wah – I know I lost some of you. Here – go read this. I’ll wait……OK, you are back, let’s keep going. Analogy time. You are stacking pick up sticks.


In your untempered chocolate the cocoa butter (your pickup sticks) are laying every which way. But once you align them, they nestle in, and as you hopefully notice, take up much less space. The same thing happens with nearly every fluid that solidifies (the glaring exception being water that expands when you freeze it (which is why it floats)).

So how does that cause the different sheen? The chocolate is also just ever so slightly adhesive, so as the chocolate sets up in the various molds, it can either come away from the walls smoothly, in one snap (if it is in a very rigid professional mold) or it can pull away slowly (if it is in a flexible hobby mold). And since chocolate does not like to be disturbed while setting up, when it disturbs itself, you see the result as a change in surface appearance.

Unfortunately, what that means is the only real way to avoid that change in appearance and have a 'professional' look is to use Professional molds - at least in regards to bar molds.

One final note, as I just thought of it. This is usually only noticeable on these longer, perfectly flat topped molds where there is one long continuous surface. The 2 oz mold shows it some, and the 4 oz bar mold even less, but most of the small cavity hobby molds don’t show this at all, partly because the curves in the surface make the mold naturally more rigid, but also because there is less to pull away at a time.

Finally, it's sort of interesting this question just came in as due to a decision of one of my main mold suppliers, the hobby mold option for the bar molds has been discontinued.  So, in very short order, once stock runs out, only professional grade will be available.



Ask the Alchemist #33

I want to make chocolate for baking. Do I need to still go through all the steps of refining, conching and tempering? How is the process of making baker's chocolate different from the process of making semi-sweet chocolate?You do not have to go through all of the steps you list above, but you do need to do most of the to one degree or another. And in one small case, I will back pedal and say you will have to do them all. First off, I want to get some definitions out of the way – or more to the point, I want to list some synonyms.

  • Baker’s chocolate
  • Chocolate liqueur
  • Cocoa mass 100%
  • Unsweetened chocolate

These, being synonyms, are all the same item. I’m going to go out on a limb, and assume that you recognize at least one, and you don’t officially need an actual definition.Way back in the dark ages of home chocolate making (about 1 BCA – that’s Before Chocolate Alchemy) I experimented with just using the Champion juicer to make one of them there things above – the result was something that looked like one of them there things, but was not one of them there things. It turns out, it was a matter of scale. Although the Champion had released the cocoa butter and the mass flowed, it had not released it all, and it just didn’t quite behave right. The flavor was muted, it was too thick, and it would not temper well. But just a couple hours refining in a Melanger, and suddenly, like Alchemy, it was transformed into one of them there things above. Going back to scale, basically that particles were just not small enough. Instead of sand, it is still gravel.

So, you need to refine. And that can occur much faster than if you had sugar in there – again, just a couple few hours. After that, you move into the conching zone. And really, I find that totally optional, and in nearly all cases overkill if you are going to be baking. I won’t refute that conching is a remarkable process…but it is a relatively subtle process that will be totally lost (to my tastes) in baking.

Now, semi-sweet vs baker’s chocolate. Gah, I had marketing terms sometimes. If there is sugar in your chocolate, you can consider it semi-sweet and most of the time, that is what we make. It’s close enough. Painting with a very broad brush, if it is not milk chocolate, and it is not 85% chocolate (that would be ‘dark’) then it is semi-sweet.

Tempering – here is that one that on the surface I want to just say ‘no, you don’t need to do that’ but, I have found in one case, where it does seem to make a difference. Chocolate chips and chocolate chip cookies. Very simply, if you are melting the chocolate down as an ingredient, then there is no reason in the world to temper it – you are just destroying the temper when you melt. If on the other hand you are, you are using some of that ‘semi-sweet’ chocolate, and you want to make your own chocolate chips (which purely for the work involved, I don’t recommend – chocolate chucks people, chocolate chucks), then there is a difference in how the chips behave during baking if you don’t temper. Simply said, we are used to tempered chocolate chips, how they hold together, how they feel in the mouth, etc, and untempered chocolate chips, while still good, seemed to lack something.

That’s about it…except for one final item.

Over the years, I’ve basically said lecithin is optional, and from the standpoint of fine eating chocolate. It still is. But what I have discovered is that if you are baking with it, and especially if you are mixing the chocolate into water based ingredients (truffle fillings, cake batters, tortes, etc) then a little bit (1% or so) greatly increases workability and reduces the chances your chocolate will ‘break’ and you will have cocoa butter floating around. There has been a few occasions that when I made truffle fillings, and tortes, both without flour or another binder, that oil floated to the top. Using the same exact recipe, but with the addition of a small amount of lecithin kept everything together and much more manageable.

OK, NOW, that’s it.



Ask the Alchemist #25

I am wondering about chocolate and refrigeration. How does it affect chocolate in setting up during molding, in storage, and in transport for shipping? Does the moisture have a negative impact?

It is kind of interesting (to me) how questions like this come up just a short time after I’ve done some experimentation. In particular, how refrigeration affects the tempering process. Let us take each stage and see how forced chilling and cooling temperatures affect chocolate.

To begin, even though it was not asked, I’m going to touch on cocoa beans, nibs and butter. If you have clean, pest-free cocoa beans, you get cold beans. No really. That’s it. It does not significantly affect how fresh your beans are or how long they keep. Most beans have shelf lives in the years. Maybe if you have a full 70 kg bag that you want to keep fresh, it might be of some use. But if you only have a few pounds, the hope and expectation is you will be using them before they can deteriorate. And really, a cold temperature is only going to extend the life 10-15% BUT the chance of moisture getting in and lessening the shelf life is much greater. Cool and dry and you are fine. And this goes with nibs and cocoa butter also. In 8 years, I’ve never had either go ‘bad’. One quick note here though. This is for raw beans. Roasted cocoa beans are a different story...but only slightly. Roasted beans do go stale after a couple weeks to a month. Not really bad – but no longer vibrant. But again, refrigeration hardly helps. The chemical reactions that cause beans to go stale are nearly unaffected by cold temperatures. All you end up with are cold stale beans. Basically fresh is best.

Moving on to tempering, I tried the following. I took some tempered, liquid chocolate from my tempering bowl and put one mold’s worth in the refrigerator, one at room temperature and one outside in the ‘cool’ weather (about 55-60 F). What I found was a little surprising to me. The two unrefrigerated ones worked just fine. But the refrigerated one actually bloomed. Why is this? Well, it’s conjecture on my part, but I think it tried to rush the crystallization process too much. The Type V crystals could not form fast enough around the seed, so at the surface where the chocolate was forced to set up, other crystals were formed, and that is basically the definition of bloom. As for the other two, the ‘cool’ one did best. Basically picture perfect. The cool temperature encouraged even, smooth crystal growth and the Type V formed through out. As for the room temperature one, it was moderate. There was just a touch of swirl on the surface. Basically just the barest hint of ‘almost bloom’. In this case, the ‘warm’ extended the tempering process too long, and a few other crystals had a chance to form on the surface. So, it’s basically the Goldilock’s syndrome. Not too hot, not too cold, but just right is what is needed for a good consistent temper. Which unsurprisingly is why there are cooling boxes and tubes in many commercial chocolate factories. Basically it’s a way to control the final stage of the tempering process.

As for storage – we are basically back at cool and dry are best. My rule of thumb is if you are comfortable, your chocolate will be comfortable. If you are in upper east or west nowhere, and it is does not get above the melting point of tempered chocolate (90-92 F) then you are good to go. If you are down south, where it’s 95 F in the shade, yeah, go ahead and double bag your chocolate (chocolate REALLY likes to absorb odors) and put it into the refrigerator.

Finally, transport. That’s tough. In the summer, even if it is pretty cool, many transport vehicles can get HOT, and if you don’t do anything to protect your tempered chocolate (like with ice or cold packs) it will most likely melt and then bloom. And depending on how far you have to ship, there may simply be no good solution except to wait for cooler weather before shipping. But I will point out that cocoa butter is FINE. I ship all the time in hot weather. The bags are double sealed, the cocoa butter melts in transport, sets up when it arrives and is none the worse for the adventure. Sure, it’s not tempered, but it was not tempered when it left here and you are going to be melting it anyway.

That’s basically it. Think comfort. If you are comfortable, your chocolate will be comfortable. Goldilocks zone baby, Goldilocks. Not too hot, not too cold but just right.



Ask the Alchemist #14

At what point in the chocolate making process should I add things like nuts, herbs or spices, and how would this affect refining and tempering?"

I’ll try and keep this short and sweet.

The base answer to when to add additional ingredients is that it all depends what you want.

Nuts – I like them right at the end, while I am tempering. If you put them in while refining, you are going to have the associated oils to deal with, and while homemade nutella (hazelnut and chocolate) is great, the hazelnut oil inhibits tempering and if you use too much (40 % or so) it won’t even set up (since oils by definition are liquid at room temperature).

Herbs and spices – first off, if you are using herbs - Water! Be aware. You really need to use dried herbs or you run the risk of seizing your chocolate. But if you keep them mostly whole and don't release the water, you may be fine.  Next. When? I personally like a smooth chocolate and like the herbs and spices added at the beginning of refining. Some people like the earthy texture of the herbs and spice and add them right at tempering time. Totally your call. Both will work.

As for tempering with chunky bits in there – it has the potential to make it more difficult. Lots of places for lower seed crystals to hide. You are probably going to want to hold at your working temperature (88-89 F for instance for Dark chocolate) for a little longer to make sure all the other seeds (1-4) are gone. And it’s helpful to get your additions (nuts mostly, but herbs and spices too) up to around the same temperature so you don’t plummet your chocolate temperature and wind up with a really hard to work with mass.

That’s about it. Add it either place to your liking. Be aware of added oils and water. Pay special attention to your temperature while tempering and take your time.

Nutted and herbed Holiday gift chocolates....what a great idea.  Glad you thought of it.



Chocolate Making 101

My dear partner Penelope put this together, noting that so far there is not one single page outlining the entire chocolate making procedure start to finish.  Well, now there is. Chocolate Making at Home 101

It won't give you everything you need in detail (hence the '101') but gives a great overview.  For all the detailed information follow the links under Alchemist's Notebook to the right.



Some musings

For some reason, there have been a few spats of difficulties lately with too thick or thin chocolate in the Melangers. One person reported only being able to get 4 lbs of chocolate into the Melanger before it spun itself out. The culprit was 3 times the cocoa butter the recipe called for. I don't know why they decided on that much, but it made the warm mixture too thin. I suggested if they wanted to use that recipe then to refine with a more moderate amount for the base time, then add the extra at the end.

I had three people write about chocolate that was too thick. One tried to cut back on the fat content too much (you can't really just randomly decide to alter one ingredient radically and expect it to behave the same) and the final on read the recipe in volume, not weight. meaning for 8 oz of cocoa butter they used a cup (really only about 6 oz), and likewise for the sugar. The "8 oz" of sugar (the 1 cup) was more like 12 oz, so they have a VERY thick chocolate that gave the Melanger a bit of trouble. So, just to be clear, all ounces are weights folks, not volumes. Finally, I may have never addressed this specifically, but it came up the latest tempering articles. You can temper over and over. You don't have just one shot. I had one customer giving away "failed" tempering batches because she thought they were totally ruined. Nope - keep it clean and dry and you can temper over and over until you get it right.



Tempering - Deconstruction and Reconstruction & Illustrated Tempering

I have put together an article on tempering. In it you will find one I wrote some time ago about some of the theory behind all those temperatures you have to worry about during tempering. New now is an illustrated explanation to tempering. My hope in both of those is that it will make tempering more approachable and less intimidating.

Tempering - Deconstruction and Reconstruction & Illustrated Tempering



Tempering - Deconstruction and Reconstruction

If you don't happen to know, the AlChemist here is also an actual Chemist. For a while now, tempering has been bothering me. Or more to the point, the lack of clear scientific information. Sure, there is a bit out there about the different forms of cocoa butter, and how you are forming a particular form (type V) that gives chocolate its characteristic snap and gloss. But there is still a lot of mystique, intrigue and lack of true explanation. Well, after quite a bit of reading and thinking, I think I have both an explanation as to what is actually happening, step by step, in the tempering process and why it works. So, without further delay, this is what I have worked out, pieced together and tested. It has lead to what I think is a new way to temper, and it involves a piece of equipment you most likely have if you are making chocolate from scratch - the Santha Wet Grinder. And it is very simple - I have tested it a number of times and so far, it seems just about fool proof as long has you have a reasonably accurate thermometer. But I will get to that at the end. On to a little theory.

You may have heard how cocoa butter forms into various "polymorphs". Well, it is a simple enough term, but I can't say it is very approachable. Poly means many, morph means shapes. So cocoa butter can take on many shapes - and we don't mean in molds here. The molecular (there I go being unapproachable) form can take on many shapes. Think of a cocoa butter molecule as a long stick, not unlike a Lincoln log. There are LOTS of ways to stack them together and some are more stable and stronger than others. If you take the whole box and just dump them on the floor, you will get a very loose pile that is "soft". If you push on it, it is going to move. That is like "polymorph I". It is a very soft form of cocoa butter as there is very little structure to it. It is what you get if you just let the cocoa butter cool or cool it very quickly. I could go WAY into the analogy here, but suffice it to say, if you take your time, stack each log up and interlock it with the one below it, your whole structure is going to be strong and stable. That is "polymorph V" or tempered chocolate.

Now, I found the following chart. I really don't want you to read it to carefully as in my opinion there is just too much information there. I want you to look at the melting points - that is the key to what we are going to do.

Polymorphs of Cocoa Butter melting point (°F/°C) comments
form I 63.1/17.3 Produced by rapid cooling of melt. Successive polymorphs are then obtained sequentially by heating at 0.5 °C/min.
form II 73.9/23.3 Produced by cooling melt at 2 °C/min or rapid cooling of melt followed by storing from several minutes up to one hour at 0 °C. This form is stable at 0 °C for up to 5 hours.
form III 77.9/25.5 Produced by solidification of melt at 5-10 °C or transformation of form II by storing at 5-10 °C.
form IV 81.1/27.3 Produced by solidification of melt at 16-21 °C or transformation of form III by storing at 16-21 °C.
form V 92.8/33.8 Produced by tempering (cooling then reheating slightly while mixing). The most desirable form with good gloss, texture, and "snap".
form VI 97.7/36.3 The transformation of form V after spending 4 months at room temperature. Leads to the white, dusty appearance of "bloomed" chocolate.

What it all comes down to is that if you let cocoa butter just slowly and naturally cool, you are going to get a mixture of types I-V (no VI as it takes months). The slower you go, the more type V you are going to get as the others can't really form if the mixture is too hot - they just "melt". So at 30 C, about all that is going to form is type V. Now, notice I say "about". Those numbers are great in theory, but in practice, a little of all of them form at all temperatures - it is just one of those crystallization/equilibration theory "things" that I took 3 months in 2nd year Organic Chemistry to really study and understand.

So, if we take some melted chocolate (untempered - no structure at all), and let it cool slowly, type V "crystals" will start to form as it cools, then IV, then III, then II, then I. What have we gained - all we have is this mass of soft chocolate with all the forms. Yes and no. What we have is a soft mass with quite a lot of type V crystals "contaminated" by the other forms. What happens if we heat this back up to 32 C? All the forms except type V melt and we are left with what is effectively type V "seed" chocolate. If you then add this to a batch of untempered chocolate that is UNDER 92.8F/33.8 C (the melting point of type V), the cocoa butter present will start to form around the seed crystals very nicely and preferentially give you 90+% type V cocoa butter. There WILL be a little of the other forms present (that whole crystallization/equilibration theory "thing") but the majority will be type V and you will have tempered chocolate.

Now, I know in "classic" tempering you stir, and scrape, and sheer and yadda, yadda, yadda. If I did that in my Organic Chemistry lab while forming crystals I would have failed. It works sometimes, but mostly it is unpredictable (hrm, tempering unpredictable, naaaa). What I always learned was to form a seed crystal, set your conditions correctly, then TAKE YOUR HANDS OFF. So many people wanted to "help" the crystals form - all they did was break them and make a mess. So, based on all of that, this is what I have developed for tempering with your Santha. It looks more complicated than it is - I like to give plenty of detail.

The AlChemist approach to Tempering

  1. Refine your chocolate to the level you desire. Verify the temperature is above 110 F and remove anywhere from 1/4 -1/3 of the chocolate. (note, chocolate tends to equilibrate at this temperature when refining in the Santha)
  2. Place the chocolate on a plastic wrap covered plate, cover the plate and put it in the oven or other semi-insulated place to slowing cool. (you are forming all the crystal forms here, with an advantage to the type V by cooling slowly).
  3. Let the seed chocolate set up a few hours. It will be quite soft as it is "contaminated" by type I-IV crystals. Don't touch it, stir it or bother it - it knows what it is doing.
  4. Once it is solid and you are ready to temper and mold up, remove the seed chocolate and chop it up into small finger nail sized pieces.
  5. Verify the chocolate in the Santha is between 90-95 F. If colder, just run it a few minutes and it will heat up. If hotter, let it cool.
  6. Add it to the rest of your chocolate in the Santha, turn it on a minute or so to mix it, then turn it off so the seed chocolate can melt. This is the advantage of the Santha. It will distribute the seed chocolate very well.
  7. Turn the Santha back on and verify the temperature of the chocolate once it is all homogeneous. You want it technically anywhere over the melting point of type IV (81.1 F) and under the melting point of type V (92.8 F) . Practically, assuming your thermometer is not perfect, a goal of 88-90 F is nice. If it is a little too cool, turn the Santha on a little to heat it up. It really should not be too warm since you are adding room temperature seed chocolate to chocolate you have verified to be no warmer than 95 F.
  8. After everything is homogenous, it is your choice how to withdraw your chocolate. I prefer to turn the Santha off, withdraw a syringe (soon to be offered for sale) of chocolate, turn it back on, and fill my molds. Then repeat - off - fill - on - dispense. During this procedure I take off the nylon nut so the chocolate is mixing but not heating (no friction means no heat).

That is all there is to it. Finally a couple quick molding notes.

  1. Polish your molds with a clean dry towel.
  2. I found no advantage to rubbing with cocoa butter - it did not help nor harm the final release or gloss.
  3. Let the chocolate set up at room temperature - give the Type V crystals plenty of time to form. If you force cool, you run the risk of forming other forms and softening your chocolate.
  4. After the chocolate is fully set up, put them in the refrigerator 1/2 hour or longer, then unmold immediately. This really helps the chocolate release from the molds effortlessly by contracting it just a little.

Happy Chocolate making.