This is from David Lebovitz' blog:
The first step is melting the chocolate in a clean, dry bowl set over simmering water, to about 115° F.
The second step it to let it cool to the low 80°s F. I drop a good-sized chunk of solid (and tempered) chocolate in, which provides insurance by 'seeding' the melted chocolate with good beta crystals. While cooling, stir frequently. Motion equals good crystallization, aka, tempering.
The last step is the most important.
It's bringing the chocolate up to the perfect temperature, where it's chock-full of those great beta crystals. This occurs in most dark chocolates between 88° and 91° F. Remove what's left of the chunk of 'seed' chocolate, and your chocolate is dip-worthy: you can dip all the chocolates you want and all will be perfectly tempered. Don't let it get above 91° F of you'll have to begin the process all over again."
You can read more about crystallization in chocolate in his blog entry:
It doesn't need to be spread out, just lowered to the correct temperature. The "seed" chocolate can be a piece of the original chocolate you're tempering, i.e. divide your chocolate into two lots about 2/3 and 1/3 of the total. The larger portion (2/3) will be melted and heated to 115 degrees, the other 1/3 will be the seed. Chop roughly. Proceed as David says. It does work.
I have a couple of his cookbooks (he used to be a pastry chef at Chez Panisse). His explanations are always straightforward and easy to understand.
I'm also researching chocolate tempering methods, and there are so many ways!
The most complicated way involves heating, then spreading onto a flat cold surface, then re-mixing with chocolate. Is that really necessary?
I just have some 70% Callebaut I want to make into hard shells for truffles. Does anyone have good, relatively simple instructions?
you don't need anything more complicated than melted chocolate...but it helps to use a good chocolate - high cocoa butter content (i recommend Valrhona) - and you need to temper it. Tempering is heating to specific melting temperatures in order allow dipping/coating & keep the fats/solids from separating upon cooling.
The temperatures are very precise (to a degree) & will vary depending on the type of chocolate you're using (bitter, semi or milk, etc). The big Valrhona blocks have tempering info on the packaging...but I'm sure the general method is available onling somewhere also.
also, a wire rack & thin-tined fork for handling your candies are helpful. Put waxed paper under the wire rack to catch the excess chocolate for reuse...