Chocolate – Tempered chocolate spheres in advance

Very simple: don't store your chocolate in the fridge. The ideal temperature for setting chocolate is 20°C. You can store it at less or more than that, but not too much. Setting in the fridge results in bad chocolate. Remember, when you work with chocolate, exact temperatures are extremely important.

Here a loose translation from a good article on chocolate/couverture coating:

This is the usual case. You only want a temperature difference of 12° to 13° between the chocolate and its environment as well as between the chocolate and the confect interior.

If the interior is colder than the room, the setting will happen "inside out". The cocoa butter film which gives a confect its shine will build on the inside, leaving the outside looking dull.

This is a really good case for some types of confect, but you can't do it with most types of filling (definitely not with strawberries). Cooling from the outside gives you a beautiful shine.

If you want to achieve a good shine, it is possible to put the confects in the fridge for a short time, but only after they have cooled to 20°C at room temperature. Don't let them fall to fridge temperature, take them out at 15°C. The continued cooling from the outside is beneficial.

This shouldn't happen. The temperature difference is too small, and the confect doesn't set quick enough. In this case, cocoa butter pools on the surface and creates a yellowish layer after it hardens.

When you make your confect, you should time the first piece. The setting should need 10 minutes. If it is less, you don't get all the possible shine. If it needs more, it will get grey or whitish yellow.

To answer your last question: yes.

Regarding the previous question, it's because the temperature at which the cocoa butter in the chocolate crystallizes affects the overall consistency of the chocolate. If you've ever eaten a chocolate bar that was left in a car on a hot day after it has cooled down again, and who hasn't, you'll know about this. Sometimes chocolate tastes fine but has a definite 'grittiness' to it: other things being equal, that's usually because the cocoa butter crystals are too large.

Cocoa butter has a number of different crystal forms, each of which will have a slightly different effect on texture and melting point. When melted chocolate sets, the cocoa butter crystallizes, and it will generally all crystallize with the structure that it starts to crystallize with. (This process where crystals start to grow is called nucleation.)

So you want to have control over the temperature at which crystallization starts. The optimum crystal form for nice chocolate will tend to predominate when crystallization starts somewhere between 18-25 degrees C (around 64-77F).

So if you think about it: when you add room temperature stuff (like a pretzel) to chocolate that is considerably hotter than room temperature, the resultant temperature on the surface of that pretzel will likely be way higher than 18-25 degrees. On the other hand, if you are dipping an item that is significantly below room temp, then your chances of hitting that window are much higher.

The surface structure of the thing being dipped can of course make a difference to crystallization as well, but for normal purposes that is marginal. To put it another way, it doesn't matter what ingredients you're dipping - temperature is key!