Tempered Chocolate

Tempered chocolate is chocolate that has been melted and then cooled in a particular, delicate way in order to achieve the desired crystal structure in the finished, solidified product. If you simply melt chocolate, pour it into a mold, and let it cool, the resulting solid will be inferior to tempered chocolate in three major ways:

• Appearance. Most people have had the experience of opening a chocolate bar that has been forgotten in a cabinet for far too long, and finding a grayish, powdery surface on the chocolate. This is called "bloom". It doesn't actually affect the taste of the chocolate at all, but it doesn't look nice. Untempered chocolate develops serious bloom in 24-48 hours, and it never gets the beautiful shine of tempered chocolate.
• Solidity. Untempered chocolate never develops the hardness, or "snap", that one expects from a piece of chocolate. It can be very messy to serve in warm conditions.
• Mouth Feel. This is the important one. It's all right to dip things in melted chocolate without tempering it if you're going to eat them right away, or you don't care about the appearance, and it's not going to be too warm. But if you want to make candy bars, or molded chocolates, or cups--anything with a largish solid mass of chocolate--you really need to temper. The texture of bulk untempered chocolate is highly unpleasant: it's chewy in a way that chocolate was never meant to be. The flavor doesn't develop properly in your mouth. It's just not right.

So what's involved in the tempering process? Basically, you have to melt chocolate, then cool it beyond its normal freezing point while agitating it to prevent it from solidifying (this seeds the chocolate with cocoa butter crystals of the correct crystal structure, as I understand the process), then warm it back up to a temperature that keeps it fluid without melting the newly formed seed crystals. This is tricky. Basically, when a recipe calls for tempered chocolate, you have three options:

• As noted above, if you're planning on dipping things, instead of casting large blocks of chocolate, and if you're serving relatively soon or you're not fussy about appearance, and if you're not expecting it to be too warm, you can simply use untempered chocolate.
• The easiest and most reliable (and most expensive, alas) option is to buy a chocolate-tempering machine. These things really exist; they are finely engineered devices for just this purpose. That kind of specialty product doesn't come cheap; mine cost $330. On the other hand, it's been a major source of joy to me, and it's my favorite kitchen toy. There are several different models available. The one I got is called the Sinsation, from Chandré, and I love it. However, the Chandré company appears to have vanished off the face of the earth, but their former R&D division is now a new company called Chocovision. I haven't really done business with Chocovision yet, but the person that I spoke to there seemed uncharacteristically smart, knowledgeable, and helpful for a customer service person, and it's basically the same machine, so you'll probably be okay with them.
• Finally, it is possible to temper chocolate by hand. It is not easy, but it's possible. You'll need an instant-read thermometer, and it would help a lot to have a heating pad as well. The idea is to melt a lot of chocolate, either in the microwave (on high, stopping to stir every 15 seconds; stop before it's completely melted and stir for a while, and the rest will probably melt from the heat stored in the liquid chocolate) or in a double boiler (over hot, not boiling water), and then add one or two large pieces of well-tempered chocolate and stir constantly until the molten chocolate is within the tempering range. For dark chocolate ("sweet dark", semisweet, or bittersweet) this is about 87-91°F. For milk or white chocolate, try 86-89°F. Your results may vary based on details of the kind of chocolate you use, so experiment. When your thoroughly mixed chocolate is well down into this range, remove the solid chocolate (the "seed") from the pool of tempered chocolate and then keep the tempered chocolate within its tempering range; the reference materials I've seen on this subject recommend a heating pad set on LOW, wrapped in plastic wrap so that it doesn't get covered with chocolate. Good luck; if you go this route, you're going to need it. In the event of a complete failure of tempering, you can always melt it down and try again.

Whatever method you use to temper chocolate, these are things you'll need to keep in mind while using it:

• Moisture is your enemy! Even a really small amount of water added to a pool of tempered chocolate will cause it to seize, forming a stiff mass that can never be tempered. (If this happens to you, chop it up and dissolve it in hot water, milk, coffee, or cream to make hot chocolate, mocha, or chocolate sauce.) Make sure everything that you dip is dry and at room temperature. (Cold things will attract condensation, introducing moisture.)
• Don't put your tempered chocolate items in the refrigerator to help them set faster; they won't set up correctly. Room temperature is the way to go.
• Try to work when it's cool and dry. I've successfully worked with tempered chocolate while it was raining, but that doesn't mean it's a good idea. If you must do so, work as quickly as possible so that it's absorbing moisture as briefly as possible.