Conching & Refining
I have noted that there tends to be some confusion when people talk about conching and refining chocolate. It probably does not help that I have even put the two processes on the same page. But I want you to understand that they are two separate processes with two different goals in mind. Sometimes conching and refining can happen at the same time, but they do not have to and often you do not want them to. Some definitions are probably in order. Conching Conch comes from the Spanish word concha, which means shell. The name "conching" arose because the original vessel used to hold the chocolate was shaped like a conch shell. Conching is a modern process used in making chocolate The characteristic taste, smell and texture (and by this, I mean general mouthfeel, not particle size) of chocolate are developed at this stage.
The process of reducing the particle sizes of both cocoa solids and sugar crystals in finished chocolate. The goal is somewhere in the range of 15-25 microns. Your tongue loses its ability to determine texture and grittiness at around 30 microns. Under about 10 microns the chocolate can get gummy. We will worry about over refining when we get there. We can only hope for that problem.
With that all said, what we have found that works remarkable well for both Refining and Conching is the Spectra 11 (previous known as the Alchemist's Stone Melanger). If you notice, it looks a lot like a commercial old style Melangeur.
On a weekly basis I get asked if there is another less expensive way to refine chocolate at home. Trust me (hopefully you do), if I knew of one, you would know about it. Right now, to the best of my knowledge, the Melanger is it for small scale (1-50 lbs). Although the list is by no means conclusive, different things we have and failed to use as chocolate refiner are as follows:
- Ice cream maker
- Blenders (many makes and models)
- Juicers (including the Champion, which is the only juicer we know of that will liquify the cocoa nibs, but still doesn't touch sugar)
- The oh so romantic Mortar and pestle
- Ball mills (homemade they were just too expensive)
- Rock tumblers (with steel shot)
The Spectra melanger has a heavy motor that rotates a granite slab (10 lbs) and two large heavy (7.25 lb total) granite rollers at about 150 rpm. The whole thing is just under 50lbs! Oh, and I just saw they say it is "light weight" - don't you believe them - this thing is a heavy duty monster - and that is great! Really, the pictures just do not due it is justice. Just have a look.
So, how do you use the Melanger?
I suggest pre-heating the bowl and rollers. Don't go over 150 F as the epoxy can fail.
Melt any cocoa butter you are going to add. Anywhere from about 120 F on up to 250 F.
If you are using liquor, melt and add it. If you are using nibs, heat them to 120-150 F and add them in small handfuls, giving the Melanger time to grind them down. Add more as it gets smooth. You can add your pre-heated sugar at this point too. There is no need to pre-grind your sugar. Regular granular sugar works great. NOTE: Do not add ANY water based ingredients to your chocolate in the Melanger. The chocolate will seize and you can damage your Melanger. After the first hour though, the chocolate becomes more liquid like and the whole thing generates enough heat by friction that additional heat is not really needed. After that, I have found a difference in texture after every hour, with "smooth" chocolate occurring around 10-14 hours. With the freshness and quality of ingredients we are using, I have found no degradation in flavor or signs of over-refining after 24 hours of refining and I have word from various customers that it performs great up to 36 hours (not that there is a problem after that, just that they refined that long). It is that simple.
If you need to stop the refining, just do. It will not hurt a thing. I turn mine off at night, put the bowl into a pre-heated oven (about 150 F, with the oven then turned off) and let it set overnight. It is usually still liquid in the morning and I can just restart the refining. If it does solidify, just turn the oven on about 150-175 and melt the chocolate. Take the cover off for better heat transfer and so you don't melt it. Finally, the bowl is held together my an epoxy that has a maximum temperature limit of about 170 F. It can handle a 200F for a short time, just don't let everything get that hot.
My latest batch of chocolate was two pounds of milk chocolate.
8 oz Ghana Forastero liqueur (melted) (20%) 8 oz cocoa butter (melted) (20%) 8 oz non-fat dry milk powder (20%) 16 oz sugar (40%) 2 g lecithin (0.2 %) 1/2 vanilla pod (split and soaked in the cocoa butter 1 hour)
After refining for 10 hours, at 1 hour increments, there was no noticeable grit left from the sugar. During that time, some conching occurred to - there was a marked increase in viscosity (which is what is supposed to happen) and some of the sharper flavors at the beginning have mostly disappeared. Conching has to occur to some degree as there is tremendous shear where the 120 rpm granite rollers rotate against the lower spinning granite slab.
This is the chocolate as it just went into the Santha
After about 5 hours you can see most of the grit has been refined away, but you should note that there is not a lot of gloss to the chocolate. It means is it not ready yet.
This is the chocolate all finished. There is a nice high gloss, and you can even see the chocolate sort of spinning off of the granite rollers.
Of course, the real test of whether it is done or not is "do you like it?" and "is it smooth enough?". Only you can answer those questions.
In addition to the above basic instructions, there is also the Chocolate Melanger Instructions and tips which give a bit more detail on how to use (and not abuse) the Melanger.
In the mean time, the following will give you a bit more detail as to what in involved in refining and conching.
Refining and(vs) Conching
The process involves heating and mixing for several hours to several days the ingredients of chocolate - cocoa, cocoa butter, sugar, lecithen and and any "flavoring" such as vanilla or essential oils. For milk chocolate, dry milk powder is also included in the mix. (don't try to use liquid milk, it will seize on you). During conching, the chocolate is heated to temperatures of 110 to 180 F, sometimes externally, sometimes just from friction. In the "industry" many Milk chocolates are heated to temperatures over 160 F to allow the lactose crystals to transition into amorphous lactose. This transition is often why milk chocolate has that soft and silky mouth feel. Some people (both commercial and at home) don't do this, and that is fine. Especially at home, it is your choice. I find the 140 F often reached in the Melanger does just fine. Regardless, during Conching the sharp taste of the fresh cocoa slowly disappears. At the same time the acidity and bitterness of cocoa are lost and the moisture content is reduced (there is actually debate over this) and the delicious chocolate flavor becomes fully developed. Simultaneously in the process, the smoothing of the cocoa and sugar particles takes place with cocoa butter forming around each of the small particles. This is different from refining really. The particles of sugar and cocoa are smoothed out in conching but not substantial reduced in size. Conching is done for several hours or up to three days. Finally, there are basically two thoughts on conching - low and high shear. When conching was discovered, there was only low shear, and this is probably why it could take up to 3 days. With modern equipment, there have been a number of conching advancements, notably high shear conches. These supposedly (there again is great debate) can conch a batch of chocolate in under 15 minutes. The high shear causes the volatile components to be quickly liberate from the cocoa mass.
There is no real right way or amount of time to conch. It is up to you and what you want your final chocolate to be like. All I can do is give you certain guidelines. Certain Criollo cocoa beans are chosen because they are bright and fruity. You would not really want to conch that for 3 days because you are just going to drive off those qualities that you choose the bean for in the first place. And you will need to keep balance in mind in that desirable and undesirable compounds are driven off during conching. The trick is to find that combination of conditions (low or high shear, high or low heat, short or long time) that give the chocolate flavor you want. Conching is probably the least understood process in modern chocolate making and consequently the most Alchemical of the processes. Finally, try not to worry too much over it. Even if you chocolate is not exactly like to want it, it is still going to be good, primarily because you are using fresh quality cocoa beans.Right now there are no heated home conchs, only the Santha that conchs as it refines. The present plan is that we can further modify the Santha to be heated. We are working on that and will keep everyone up to date.
We have come a long way since Chocolate Alchemy started. You if want, you can go read some of the History.