artisanal thinking

I have officially become a chocolate maker! For, yesterday, July, 22nd 2009, I ground the nibs I had roasted the previous day, attempted to temper the melted chocolate and molded my craft, resulting in nine extravagant, mellifluous, brown-speckled and … highly experimental chocolate bars. Nevertheless, I now consider myself in the ‘alpha’ release, although the hope is, unlike google, or even web-2.0 chocolate maker TCHO, I won’t confine myself to beta for years and years… How did we do this—what is conching, refining, tempering and molding? Follow me, reader!

Introduction: A Further Roast

On Tuesday, July 21st, 2009, I attempted my second cacao roast, this time with 8 cups (about 2 pounds) of Panamanian beans and drawing from my last experience, with the intention of a more intense, but shorter roast. In this roast we were trying to bring out more of the ‘bean profile’ and less of the ‘roast profile,’ in other words, not as burnt… I multitasked, and warmed up the oven by roasting some almonds, eventually bringing the oven to a stable 400 F. The idea is to come in with high heat to give the beans some ‘thermal momentum,’ ensure good separation of bean and husk, then to back off so as not to burn the outsides of the bean.

Log of the roast notes initial 8 minutes cooling from 400 F to 350 F, at which point we had a cocoa smell, but fainter than last time. Another 18 minutes cooling to 300 F, then a final 7 minutes in the cooling, turned off oven. At their peak, the beans read about 235 F, much cooler than the previous roast. Our initial interpretation was that these nibs had a more distinctive chocolate flavor, whereas the previous roast yielded more nutty nibs. After cooling, we ground the nibs in the Crankandstein, (maybe not cool enough, as they were actually steaming in the bowl!) and took them outside to winnow with a hair dryer. Earlier in the day I stopped by H&H Restaurant Supply (nice people, but a little disorganized…) to pick up a couple of baking sheets and a large steel bowl, which made winnowing quite easy. We ended up with a little over 6 cups, a 75% yield.

More Equipment. More Stone.

On the advice of Laurence Mate I checked out the Champaign Preservation and Conservation Society (PACA) for a scrap stone slab on the cheap. Melted chocolate is traditionally tempered by spreading it around on a marble slab while it cools, then mixing the cooled chocolate back with some warmer chocolate. I originally called some local stone countertop cutters, who wanted ~$50/sq. ft… too spendy. At PACA I found a very nice piece of marble, measuring 2 and a quarter feet square, and three quarters of an inch thick. I paid only $30 for it, working out to only $6/sq. ft., a screaming deal!

In anticipation of my stone purchase later in the day, I rose Wednesday at 6am (embrace dawn!) and took my nibs and the bowl of the Santha grinder out of my oven, where I had let them warm up overnight and readied the grind. Because we are grinding and refining nibs directly in the granite Santha grinder, rather than using a juicer or some similar equipment to first grind them into cocoa liqueur, it is important to heat the nibs to about 120F so the fat contained within them liquefies more quickly. We also add them slowly, a handful at a time, otherwise the mass of nibs will compress and clog up under the wheels of the grinder, and nothing will be ground. As I was adding the nibs, I sifted out any remaining pieces of husk, and besides occasionally using a spatula to direct some of the nibby paste under the granite rollers, everything went quite smoothly.

The mass in the grinder, however, wasn’t smooth for another 10 hours. Above and to the left is what we had after 2.5 hours—a flowing liquid of melted coarse chocolate. Prior to this I had added 2 cups of (fair! trade! organic!) sugar, which together with 6 cups of nibs gives a 75% dark chocolate. The friction of granite on granite and the heat of the electric motor cause the grinding chocolate to hold a temperature of around 125 F, sufficient to keep it in a liquid state, and besides its coarse texture, at this point we had a bona-fide tasty chocolate fondue!

Nothing very notable happened while grinding (a good thing), and after 11 hours of refining, we ended up with what you see to the right. It is worth noting here that a desired side effect of the prolonged and warm refining stage is another related, and not very well understood process known as conching. The goal is to mellow the sharp taste of cacao, coat each cocoa particle with cocoa butter, and drive away volatile compounds that cause acidity and bitterness. Conching achieves this by a long period of gentle heat and continuous mixing of the ingredients. The temperature can vary between 110 F and 180 F and the time from hours to several days, but with a consistent temperature of 125 F and high shear from the granite rollers, we hope the Santha is conching the chocolate as it is refining it down to micron-scale particles.

Tempering, Molding. Achieving Correct Crystallization.

After refining and conching, after bringing home and cleaning my new (I won’t tell you what it was used for in the past) marble slab, I was ready for the final and most hands on steps towards bar-dom. In particular, we now had melted chocolate, but if we were to just let that cool, various crystals from 6 possible types would form in the hardening chocolate. We would have chocolate with a matte rather than shiny finish, which melted easily in your hand (NOT in your mouth) and which had little structure, little snap to it. That is untempered chocolate, and it occurs because we don’t ensure the correct crystallization of the chocolate particles. There is a particular type of crystal we desire, with the austere name, ‘type V’ (as in 5). Type V crystals melt at 94 F and form down to 80 F, there are five other types of crystals, each with its own melting temperature, from low to high.

The idea in tempering is to take a bowl of 100 F chocolate, ladle out about a third of it, and just start spreading it out on your slab, then pushing it together again. You do this until it has cooled to about 80 F at which point type IV and V crystals have started to form. Then we add the cooled seed crystal chocolate back to the warm chocolate, hoping the resulting mixture has a temperature of about 90 F, but never more than 92 F. The reheating will melt the worse type IV crystals, but not the nice type V. Sounds pretty straightforward, but this is one of the most artistic steps in chocolate making. I tried my best, however I think next time I will take out more chocolate and let it cool further before recombination. I ended up with a reading of about 91.5 F which was dangerously close, but I decided to go ahead and mold anyways. I was worried about the chocolate cooling too much and thickening up before I had time to pour it all in molds, but I think this worry proved unfounded.

This time we used 4 oz. bar molds, each plastic sheet has 3 molds in it, and we used 3 sheets, which means we started with at least 36 oz. of melted chocolate (more than I expected!). I used a plastic spoon to ladle the chocolate into the molds, but next time I will definitely try to use a syringe. At this point, melted chocolate was everywhere, on my hands and tools, covering the slab, dripping onto the sides of the molds as I ladled, but there was basically no way to clean it up, so I just embraced chocolatiness! After filling each mold with melted chocolate, I picked the sheet up and rapped it several times on the marble slab in an attempt to get the chocolate to settle and to force bubbles to the surface. More technological folks have chocolate vibrating tables for this purpose…

We finally let the molded bars cool in the fridge for about 40 minutes, then demolded them onto some tin foil and tried them out! As I had worried the temper was not great and there was not the clear snap we were looking for. They melted a little too easily in my hands and the chocolate was grainier than I had hoped. The flavor is good, I think! A little smoky, and even though it is 75%, not very bitter; fresh, maybe a little grassy at first? Who knows! Try for yourself! We broke two bars width-wise into 4-block rectangles and wrapped them simply in tin foil, then gave out free samples this morning in Caffe Paradiso. Apparantly they were gone in about a half-hour, cool!

I think this was a good first step and I have a good idea of where to improve in the future. When I get back from my sister’s wedding and move apartments, I am excited to try again!

This entry was posted on Thursday, July 23rd, 2009 at 5:09 pm and is filed under Chocolate Making. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.