Chocolate Alchemy The Art & Science of Homemade Chocolate Thu, 26 May 2016 17:36:20 +0000 en-US hourly 1 Ask the Alchemist #161 Thu, 26 May 2016 17:35:29 +0000 Level: Apprentice

Read time: 7 minutes

I have been making a batch of chocolate over and over.  It is sharp and astringent.  I think I keep over roasting it but nothing works.  I have tried roasting from 250 to 300 degrees for 15-30 minutes.  What am I doing wrong?


Somewhere along the line the trend has been to roast cocoa lighter and lighter for fears of not over roasting it.  That is an admirable goal.  You don’t want to over roast your cocoa.  Unfortunately this is the classic result that I am seeing every single week.  Effectively under roasted beans or possibly even raw beans that are sharp, astringent and lacking in chocolate flavor.

Before we going any further, I want to define who I am talking to.  If you like your chocolate and how you are roasting, then this article isn’t aimed at you.

If there is that little voice in the back of your head wondering why you chocolate isn’t quite right and you are fearful of over roasting because all the experts (self proclaimed?)  out there who have never roasted a cocoa bean in their life warn against over roasting, then maybe you should read on.

I’ve tried to over roast.  It is REALLY hard.  I’m talking  you have to try to over roast and you still might fail.  I’m not joking here.  I am kind of dumbfounded where the idea came from that it is easy to over roast cocoa let alone that it burns easily.

Let’s talk about roasting.  As in really what is happening.  To do that I need you to put away what you think you know about roasting cocoa and instead engage what you know about cooking and baking in general.  Because the rules are the same.  There is nothing special or magic about roasting cocoa beans.

Ok.  Agreed?  Great, let’s begin.

What has to happen when you roast?  You need to take a cocoa bean that is around 70 F and take the whole thing, all the way to the center, to somewhere in the range of 230 to 260 F.  From experience, I have learned that I personally like it best when that can happen in 15-30 minutes.  And anecdotal evidence suggests so do most people.  So that is what we are going to talk about.

I said this is like any other cooking or baking.  So instead of a cocoa bean, let’s talk about roasting a hunk of meat.  Or loaf of bread.  Either works fine.  I’m picking those because they are usually 2-3 lbs, start at room temperature and come to some higher final temperature.

What is the classic way to roast these?  350 F oven for an hour is not uncommon for either one.

You put your loaf/roast into a 350 F oven.  Here is the first important thing.  The surface does not immediately become hot.  After 10 minutes, the surface is probably only 100 F and the interior is still room temperature.  And you are not surprised, right?  As time progresses, the heat sinks in.  Two inches in becomes 90 degrees, 1 inch in is 100 degrees and the surface is 110.

Notice the gradient?  That is how the whole roast is going to proceed.  At 30 minutes in the surface might finally be starting to get hot to the touch.  150-160 F.  But If you put in a thermometer to the center you will find the very center is still under 100 F.  Raw.

Not until nearly an hour later is the center getting to 150-160 F for a small roast and maybe 200 F for the bread. The meat has more water so it heats more slowly if you were wondering.

Roasting cocoa is the same.

But cocoa beans are not a loaf of bread I hear you saying.  Well, they kind of are.  They are a solid like mass in the pile they are in.  You can speed the roast along by stirring.  Distributing the heat.   This is exactly why I suggest stirring every 5 minutes.

And let’s look at a few other common things you bake.

Muffins or cup cakes.  350-375 F for 15-20 minutes.

Biscuits 400-425 for  12-15 minutes

What would have happened to either of those things if you had put them in at 250-300 F?  Totally under baked,  right?  Yep.

It’s all the same thing.  Cocoa behaves exactly the same.  Why wouldn’t it?  They are not magical.  It takes quite a bit of heat and time to heat them all the way to the center.

You are worried about burning them at 350-400 F I hear you say.  You notice that gradient I talked about?  That is why they don’t burn.  The oven can be 450 F even at the start.  The only way for the bean (or you bread) to burn is if the whole entire thing is that hot.  But it isn’t.  The heat is continuously sinking in, in effect keeping the surface from burning.

I know many of you are shaking your head in disbelief.  This isn’t just my theory.  I spend a few weeks recently testing just this.  Look a little of the data.

Temperature plot

Those are actual surface temperatures.  From everything we have seen the interior has to be cooler.  They don’t have a choice.  Absolutely none of those beans were even close to burned, let alone even over roasted.

What that means, even at 300 degrees for 30 minutes, your beans probably never made over 150 F on the surface.  Which means 100-115 F inside.  Raw by any definition for the majority of the bean.

That is why they were so sharp and astringent.  They were massively under roasted.  They were still raw.

It’s really that simple.  It takes a lot of heat to roast cocoa beans in any reasonable amount of time.  And to keep it to a reasonable time, you have to have a hot environment.  Heat flows and how fast it flows is proportional to how big the difference is between your beans and the oven.  At 300 F, although it seems hot, it  isn’t that different from your target of 250 F.  The consequence is it takes a long time to get there.

Just think about baking bread or a roast of beast and go from there.   Be fearless.

So get the beans in the hot oven.  Stir them often to help the heat distribute.  Take temperature readings (I use this IR thermometer) and stop worrying you are going to burn the beans.

Be fearless.  It’s only chocolate.

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Ask the Alchemist #160 Thu, 19 May 2016 16:53:49 +0000 Level: Apprentice

Read time: 4 minutes

After winnowing I was told to remove all excess of twigs from the nibs (which is the root of each bean- see picture attached) otherwise my chocolate would be bitter! The task is huge!!! We can only remove 2 pounds per hour per person so for me it is rather an additional stress.

I have been grinding 3 different batches. The first 25lbs batch I left it for 24hrs. It was good but a bit over roasted, the second was much better and I left it for 36 yours. I tried a batch with the “twigs” to taste the difference and this batch grinded for 36 hrs too. I agree that it tasted bitter in the grinder but not so bad once tempered….Please give me your thoughts on these twigs.



My opinion is that it is utter nonsense.  And I’ll say it again, it is my opinion.

Now let’s talk about it.

Those twigs are called the germ of the cocoa bean.  The theory goes, as you described, is that they are horridly bitter and must be removed to make quality chocolate.  I’ve heard this over and over, and have yet to see any solid proof of it.  Just opinion.  Which is all I am giving you.

But try this.  Get a roasted cocoa bean.  Look to the large end.  You will see a small circle like indentation.  With your fingers or tweezers pull out the germ.  Or just crack the bean and pull it out.  Taste it.   Chew it up really well.

Is it bitter?  To my tastes it is not.  It’s a bit harder than a nib (but it will still refine down), but mostly I find it woody and neutral tasting.  And even if it were, how could something that amounts to less than 1% of the weight of the chocolate ruin it?  I have real trouble believing that.

So maybe it reacts with something in the chocolate and makes it bitter?  Great theory, but having done tasting after tasting, I have yet to find that substantiated.   I cannot taste any difference and I’ve never met a person that can tell me from a blind tasting whether a chocolate has had the germ removed.  I’ve only seen the reviews where a bar is raved over and it is disclosed that the maker has gone to the extra trouble to remove the germ.

Correlation is not causation for one.  And two, that sound suspiciously like cherry picking data or knowledge based bias.  You know it does or does not contain germ and skew your expectations and what you think you taste accordingly.

And also the assertion does not take into account the huge number of award winning chocolates out there that have germ.  It seems conveniently ignore that.

My suggestion is to do the test again.  Make sure you use the exact same roast batch and that you blind taste the results.  And in a perfect test, have more than just two samples.  Make up 4 of each and taste them all.  Blind.

I’d put money on you not being able to tell them apart reliably.

If it turns out you can, then ok.  I’m a supporter of data and YOUR tastes.  If you like it better without germ, then by all means remove it.  But do it because it REALLY makes a difference AND you like the difference more.

My suggestion as always is to make the chocolate you like.  And not do extra work that is not needed.

In my case that means I ignore the germ.  And think you should too.

Those are my thoughts.

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Direct Trade Vietnam is in Mon, 16 May 2016 22:47:26 +0000 Today is all about Direct Trade.  It’s been six months coming, but 3 new beans are finally here from Vietnam.  And all of them are big, bold, intensely flavored beans.  Just look how round the displays on all the spider charts are.  They are just big everywhere.

Ben Tre – The flavor is big and intense. It is tangy and the deep sharp flavor of raisins and a hefty doses of chocolate.

Lam Dong – Fruit cake.  In so many ways that sums up this bean.  Chocolate aroma with a touch of allspice. I have to admit,  I actually moaned (just a little) with my first bite.

And Tien Giang – This chocolate is high in spice, tobacco and nutty flavors.

And on the chance you missed it, go check out the other new Direct trade bean that is in.

Honduras Wampursirpi.  In particular, check out the Details tab.  I just updated a bunch information about Biosphere and what they are actively doing to support the farmers and communities in the region long term.  I’m really stoked about all they are doing.

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Ask the Alchemist #159 Thu, 12 May 2016 17:40:16 +0000 Level: Alchemist

Read time: 8 minutes.

Would you have a graph showing the temperatures at which type V crystals melt for different chocolates?

Part two

If you have not read last week’s answer, go ahead and read it.  I’ll wait.

Good.  You are up to speed?  Good.  Let us proceed.

One of the big problems is that different ingredients change your tempering temperatures in different ways.  The more cocoa butter you have, the higher you will be able to take your chocolate.   Similarly, the more sugar you have, the cooler you need to keep your chocolate.  Have a look at these graphs.


Basically, the two changes cancel each other out.  Which makes sense.  If you have more sugar, and the added cocoa butter is constant then you have to reduce the cocoa beans which reduces the overall cocoa butter.  But notice too how the data is all over the place.  It isn’t really predictive.  There is a general trend.  That’s all.  It’s because, as you know, tempering  has a lot going on that affects it.

The method you use be it slab or bowl or machine.  How much you are tempering has an effect due to heat loss.  And your ambient temperature likewise will have an effect for that same heat loss reason.

Look.  I know this isn’t really helping you learn to temper.  And it can be kind of discouraging.  My point in all this is that graphs are not practical day to day.

But the general trends can be helpful.  More cocoa butter gives you a higher temperature.  More sugar less so. To combat more sugar, a little more cocoa butter will probably be a good idea.  Those are the kind of things I want you to be able to think through.

Alright, one more thing.  This last part is about the subtlety of tempering.  In short it is another reason that graphs are not practical in day to day use.   Recall those graphs above?   Notice how although there is a general trend the data’s predictive power really kind of sucked?  That is because there is another variable at work here mucking up the works.

It has everything to do with how much Type V seed you have in your working chocolate and at what temperature you are working at.  Most people who work with chocolate know the word tempering.  They know in general it is a process.  That of making Type V crystals so that their chocolate will have a nice snap.

What many don’t realize is that while you are in the middle of tempering, lots of things are going on.  From what I can tell the generally understood concept is that you are make or adding Type V seed and as long as you are holding it a the right working temperature, nothing is going on.  The Type V is stable and just waiting for you to pour it into molds.

But that isn’t the case.  Double negative alert.  Nothing never happens.

And I bet you have seen this.   You are at the perfect 89 F.  You are keeping it right there.  You are pouring your chocolate into molds.  You go back for the next ladle full…..and the chocolate is thicker.  You check your temperature.  Yep, still 89 F.  Did you get water in it?  What’s wrong?  It was working perfect, now it isn’t.  You rush to finish only to find you last bars bloomed because you had to over work them.

What happened and what could you have done?  The answer lies in the fact that (get ready for it) nothing wasn’t happening.  i.e. something was happening in your bowl even if you didn’t see it.  What was happening was that you set up the perfect conditions (like you want to) for Type V crystals to form.  So they formed and your chocolate got thicker.

What could you have done?

As sacrilegious as it sounds, you need at that point to heat up your chocolate and start destroying some of the Type V crystals.  There really can be too much of a good thing and thick chocolate while you are tempering is the demonstration of that.

But remember, nothing is never happening.  As you heat up your chocolate (say 0.5 F BTW) you start to destroy some Type V.  But recall, you also have perfect conditions to form Type V.  So even though you getting rid of some, you are also forming some.  The key is that those rates are different.

Analogy time.  You are building a stack of blocks in the back of a moving van.  That is your job.  You can’t stop.  Soon the stack gets too high and they can’t moved around without them falling apart (i.e. molding up with streaking because the chocolate is thick).  So you need to some else to take some blocks off while you keep building (because you can’t do nothing).  So Bob (your uncle) starts to unstack blocks on the really tall stacks while you keep adding more on.  He is removing, you are adding.  As long as he doesn’t work faster than you (you don’t get the temperature too hot) all is fine. There are plenty of stacks for you both to work on.

Now here is the key.  When do you put Bob to work?   If you put him to work too early (have too warm a temperature) tearing down blocks, while your stacks are small, it might be he would not let you form any at stacks (Type V) at all.  If you put him to work too late your stacks are too big and unwieldy (the chocolate is too thick).

This is why tempering  temperatures vary too.  They are time dependent and also vary depending on how big your stacks are.   Your goal is to find the sweet spot where you are building and Bob is tearing down while you have a bunch of stacks that are not too big.  Sometimes you have to heat things up to make Bob work faster, sometime you need to cool things down if Bob is out pacing you.

This is why tempering machines  (AT THE RIGHT TEMPERATURE) work so well.  They are working in that sweet spot.  Building and tearing down at just the right pace.

Let’s bring this all together now.  You can see now why those temperature points were all over the place and at some points even higher when they should have been lower.  It was related to how long the session was and how much Type V was there initially.  A temperature that would ruin your temper at the beginning (say 90 f) might well be needed by the end because you have crystalized more Type V and need to reduce amount some so it can remain workable.

Basically maximum or optimum tempering temperature is a moving target and simply cannot be plotted on a 2 dimensional graph.   You might get somewhere plotting 3D like this:

3d plot


But in reality you are probably going to need something with 5 or more variable to do it justice

5d plot

I don’t think so!

5d reaction


My suggestion is just live with knowing it’s in the high 80’s to low 90’s and go from there. It’s what all those graphs boil down to anyway.

Good luck and happy chocolate making.

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Ask the Alchemist #158 Thu, 05 May 2016 14:13:45 +0000 Would you have a graph showing the temperatures at which type V crystals melt for different chocolates?

I get this or some variation of this question once a month it seems.  It is totally understandable.  It would be really great to know that if you have a 60% chocolate, you look it up on a chart, and find you can always take it to exactly 87.6 F without having it bloom later.

Unfortunately it is also completely impossible to produce for a lot of reasons.

There three main reasons.

  • Different cocoa beans contain different amounts of cocoa butter
  • Different cocoa beans contain different types of cocoa butter
  • You have no good way to know those exact amounts.

What this means is that a 60% chocolate made from beans from Peru will have a different amount of cocoa butter (what is getting tempered) than a 60% from the Ivory Coast.  The former bean may have 50% cocoa butter but the later 57%.  That right there will change the maximum tempering temperature.

Different amounts of cocoa butter change your tempering temperatures.

But even if we get rid of that variable it still will not help us.  Let’s say we are told the cocoa butter percentage, and press out single origin butter to add back so they are the same amount, then you still can find that the 60% chocolates have different maximum melting points.

The reason is that all cocoa butter is not created equal.

I have to resort to a bit of basic chemistry.  In its simplest form,  cocoa butter is made up of three parts (fatty acids).  Each part can be one of 7 different fatty acids (although 3 commons ones are used 95% of the time).  The longer the fatty acid, the higher the melting point.

Look at the three examples of what cocoa butter can be made up of.


Notice the difference?  How as you go down, the parts get longer?  As that happens the melting point goes up.

That fact right there, coupled with having no way to find out just what combination you cocoa butter has defeats us if we try and build a graph.  If you cocoa butter has more of the first type, you melting point will be lower than if it has more of the third type.

How much lower?  Probably about 2 F.  Which is why there is always a range when giving tempering instructions.  ‘raise to 87-89 F’.

On the other hand, if you are talking about just one bean and different percentages of sugar and cocoa butter, now that can be graphed.  But you have to do it yourself for it is unique to your recipe and cocoa bean.

And I am going to talk about that next week, and why in reality if you do it you may find it less than helpful.  Stay tuned.

And always

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