Started filling the chocolate molds today, with the milk chocolate ones coming first. It’s been a long time since I tried tempering milk chocolate – normally I work exclusively with dark chocolate – and despite careful attention to temperature, I botched it. I got pretty close, so the molds do release cleanly (well, most of them anyway), but the results are streaky and spotty and tend to stick to the mold. Not usable.
Fortunately, the chocolate isn’t ruined or anything – I simply need to remelt, re-temper, and re-pour. It’s a pain in the butt, but I can manage. But it’s reminded me of the difficulties I used to have tempering chocolate.
But what, you ask, is tempering?
Basically, it’s the same principle as making fudge. Fudge is a sugar syrup that will crystallize eventually. The best fudges are made up of millions of teeny-tiny sugar crystals, so it melts smoothly in the mouth and doesn’t feel grainy on the tongue. If it crystallizes slowly, then big crystals form and you get a grainier fudge. That’s why you cool the sugar syrup rapidly (so no crystals form) and then beat it to get all the tiny crystals to form all at once.
Chocolate is somewhat similar. The fat in chocolate (cocoa butter) crystallizes as it cools. Big crystals result in a dull chocolate, with streakiness, or little stars, and a crumbly, unpleasant texture. Lots of small crystals, on the other hand, produces chocolate with a crisp snap and a smooth texture. So you want the fat to crystallize into lots of little crystals.
Well, there’s a catch. Cocoa butter (the fat in chocolate) actually has four or five crystal forms, only one of which is stable at room temperature. The others, over time, will migrate slowly into the stable form, but that slow migration results in large crystals of cocoa butter, producing a mis-tempered chocolate. So if you simply cool chocolate down quickly, you wind up having lots of unstable crystals, and the chocolate isn’t properly tempered. What you want, for good chocolate, is to get the chocolate to the exact temperature where all the unstable crystals are melted but the stable seed crystals remain.
The classic technique for doing this is to work the chocolate on a marble slab. You heat it up to about 120-130F, to melt all the crystals, then cool it rapidly to about 83 F to induce crystal formation. This puts a lot of unstable crystals in the mix, so you then raise it up to working temperature, 88F or so, to melt the unstable crystals. And presto! Nice, tempered chocolate.
This probably sounds difficult. And it is, in fact, very difficult to get chocolate tempered correctly. You need precise temperature control and good omens from the culinary gods. I had many failures before I took a month or two of weekends and spent it apprenticing to a professional chocolatier, who taught me how to temper chocolate by testing the temperature on my upper lip. And darned if that didn’t work a sight better than using a thermometer! From then on I have never had trouble tempering dark chocolate.
Unfortunately, my finely calibrated upper lip test doesn’t work for milk chocolate, which requires different temperatures from dark chocolate. So I used a thermometer on it, and like I said, I didn’t get it quite right. So I will have to do it again tomorrow. Luckily, my dark chocolate tempering worked perfectly and so I have a set of eight dark chocolate molds done. Two more batches of tempered dark chocolate should get me through the rest of the dark chocolate molds.
I’m a bit torn about what to do tomorrow. I really should be casting more chocolate molds, which of course means tempering more chocolate. However, I have a job interview at 1:30pm tomorrow afternoon, and chocolate has a way of getting everywhere. I’m not sure I want to turn up at a job interview with chocolate under my nails! So I may mix up some ganache flavorings, not sure yet.
I have also realized that I am perilously short on chocolate. I’m down to maybe 20 lbs. That sounds like a lot until you realize that I have 16 different types of chocolates to make, mostly in units of at least 1 pound…so I’m not sure I have enough. Fortunately Made in France is having a warehouse sale on Friday, so I will probably run down there and get another 12-13 lbs of chocolate. That should be enough to tide me through the rest of the batch.
I should mention that I am considering doing a systematic study of fudge after this is all over, playing with acidity, fat, and sugar percentages to see what affects fudge’s texture and understand how to adapt fudge recipes at will.