Originally posted by jupaka
I have a problem and maybe someone can help me. The top of chocolate bars become like marble, I think maybe, my moulds was prepared not right. What is the best method for clearning chocolate moulds.
Thank You very much
p.s. Sorry for my English
People have mentioned the “out of temper” problem – and I am virtually certain that this is what you’re experiencing – but nobody so far has explained what temper *is*. Since it’s possible you’re not familiar with this term, an explanation.
The fat in chocolate, cocoa butter, doesn’t have a single melting/crystallisation point. Rather, there are many, and depending on what temperature it’s at when it solidifies, it can fall into various crystal forms. Only one of those, however, gives chocolate the right texture and stability. So it’s critical that you make sure that it solidifies at this temperature. This process is called “tempering”. Here’s what’s involved.
The basic idea in principle is that after melting, you cool it down to a specific temperature (just below the solidification point for that correct crystal form). You then stir it in a specific way to encourage proper solidification. Then you very gently warm it ever-so-slightly, then pour into your moulds. Hopefully at this point it’s been tempered. There are a few approaches to doing this in practice.
Method 1 uses a marble slab and palette knife. You pour about 1/2 to 2/3 of the chocolate onto the slab, spade it around with the palette knife until it just starts to solidify, then quickly scrape it back into the rest of the chocolate. Then stir once again and pour.
Method 2 uses a bowl and some pretempered chocolate. This only works if you’re simply remelting tempered chocolate you intend to use in some way, because otherwise you won’t have the pretempered chocolate to hand. Anyway, you get the pretempered chocolate in nice little bits. Then, after melting, let the chocolate cool to about 30C, stir in the bits (these are called the “seed”), and stir. Try to get the chocolate into a good glossy, stiffening mass.
Method 3 uses a bowl and a dual double-boiler rig. The first double boiler contains hot water, the other warm to tepid. What you do here is after melting over the hot, pass it over to the warm to tepid and allow to cool, spooning the chocolate around the sides, until you see signs of it getting solid at the rim (and it should have a nice sheen). At that point, stir well and put it very briefly (seconds at most) over the hot water. Then pour into the moulds.
Method 1 is generally the most successful and reliable, although it requires the most specialised equipment. Others trade off various aspects of ease and convenience against certainty of result. In all 3 cases, you will find it much easier going with a chocolate tempering thermometer which is a sensitive, fast-response thermometer tuned to the critical range (35-25C). Practice is also useful because as everyone will observe, in time you can make the judgements visually and will be able to temper in your sleep.
Apologies to NG regulars for the long explanation of what most of you already know. I figure this problem is so diagnostic and by the OP’s remarks it seems clear the possibility exists he isn’t familiar with tempering that I thought an elaboration was in order.