I have this question bothering me for a long time and am happy to find this forum. I hope my question can be answered.
I saw the microwave tempering process-starting with pre-tempered wafer, heat at different interval in microwave. Make sure it is melted but less than 91F. Than the chocolate is tempered. I tried it and it works! So in this logic, I can just have a warmer at constant 90.5F to melt the chocolate and have tempered chocolate all the time?
If this makes sense, why do I need temper machine, as long as it starts with tempered chocolate? ( I know it can not make sense but what makes it nonsense?)
If you can keep (dark) chocolate at that 90-91F. temperature, you are fine, but sometimes reality intervenes: If, for example, you are using chocolate left over from a previous session, it is very unlikely still to be in temper and must therefore be raised to high enough a temp to melt out all the crystals. I use your method (of very careful melting-though I do it over a water bath and not in a microwave) if I am doing a small amount (e.g., for a ganache or for decorating finished pieces), but it is very difficult to melt a large amount (e.g., for dipping pieces or filling molds) and keep the temp within the final working range.
I tried on milk chocolate and it worked too.
But if I have a 90.5F holding tank with a dispenser, never let it cool down or empty. Would it be fine?
My impression from reading (and experience) is that with time too many Type V crystals form, and the chocolate will thicken too much to be usable--even if the temperature reading has not varied at all. At that point there are options (heating up the chocolate a bit or adding some warmer untempered chocolate), but you can't just let the chocolate sit there forever. Tempering machines continually adjust the heat to slow down this process, and with melters, the user can adjust the temp manually, but the over-crystallization is likely to happen eventually--and you can only turn up the temp so far before the chocolate is out of temper.
got it! Thanks. I will go ahead with a temper machine. They are absolutely there for a reason.
I didn't mean to say a tempering machine is better than a melter. Many people like the melters because they can hold more chocolate and allow you to empty a mold much more easily. And I think it is fairly easy to adjust the temperature up and down so as to deal with over-crystallization. I myself like a tempering machine because I don't use huge amounts of chocolate at a time, and it takes less chocolate to get a tempering machine bowl to a usable level than it does for a melter. I also like that a tempering machine requires less attention and so I can do something else while the process is going on.