Chocolate – Trouble tempering Valrhona Couverture Manjari (64%) Chocolate

Chocolate is an odd substance when it comes to melting and hardening. When chocolate hardens, its melting point will end up being just a few degrees higher than the hardening temperature.

When chocolate crystallizes at high temperatures, it forms a strong, dense crystalline structure that, texture-wise, is quite brittle. Most bought chocolate (baker's chocolate and chips) is already tempered, but when you melt it, you break down that crystalline structure, and if you harden it at room temperature then it ends up forming very weak crystals that will melt in your hand.

If you use a special coating chocolate (couverture or the lower-quality compound chocolate) then you don't need to worry so much about tempering (although it's still a good idea), but if you use ordinary chocolate and don't temper it then your coating will end up being messy and wet and rub off on your hands while you eat it. It might even melt while stored.

Tempering is the key to making a room-temperature-stable chocolate coating. If you don't do this, you'll need to keep your pastries refrigerated until they're ready to consume.

First of all, if by marbling you mean spreading chocolate on a slab, then your chocolate may be tempered. If you heated the chocolate properly and slabbed a good portion of it then when you add the slabbed chocolate back in, it will temper all of the chocolate. Your "problem" may be that the chocolate was actually tempered.

I'm also a little confused about how you are judging the interior to be out of temper. Other than the "snappiness", the quality of the interior chocolate is almost never used to judge temper. If you could provide a picture of what the inside and outside looks like that would be very helpful.

Aside from that, there are a few possibilities:

• How long did you wait before judging the temper of the outside? Chocolate may not show signs of streaking for up to 24 hours.
• Polycarbonate molds when used and, more importantly, washed correctly will build up a layer of cocoa butter. This layer of cocoa butter may help encourage the chocolate to form the correct crystals (temper).