Jim - this may be the case with wholesale chocolate such as Valrhona, but it does not seem to be for bean-to-bar chocolate. At least that's been my experience. With bean-to-bar a number of issues come into play such as potential lack of seed (you don't have the tempered chocolate to use as seed until you make the chocolate and temper it, leading to a bit of a catch-22 situation), non-trivial differences in varietals, little or no added cocoa butter in the chocolate making process, etc. In general, I think those of us who make our own chocolate tend to struggle more with the tempering process.
As for myself, for example, I've almost never experienced over-crystallization. Maybe once or twice. My biggest problem was getting my single origins to temper well at all. With a lot of trial and error, I finally found that I had significantly more success with the lower temp and larger delta. Maybe other chocolate makers here will disagree, but it's the only thing that ever consistently worked for me.
The EZTemper, at least so far, has changed my process in a very positive way. Here's how:
PREVIOUS TEMPERING METHOD
1) Melt untempered single origin chocolate in Rev Delta (or pour straight from the melangeur)
2) Go through custom-programmed tempering cycle (which depending on the amt of chocolate would take 2 hours or more)
3) Pour "tempered" choc into large molds (This first tempered chocolate was almost never tempered very well)
4) Take most of that first "tempered" chocolate and run it through the entire process AGAIN, setting aside some to use as seed
5) Pour the second tempered choc into final molds (This second tempering usually did the trick, but not always)
EZTemper METHOD
1) Melt untempered single origin chocolate in Rev Delta (or pour straight from the melangeur)
2) After melting, lower temp to 92º
3) Add 1% precrystallized butter by weight and stir. Wait a few minutes. You're done.
My previous method took 4-5 hours per batch, and gave me an 80%-90% success rate.
The EZTemper method takes less than an hour, and so far gives me a 100% success rate.
Significantly easier, faster and more reliable tempering sessions with less wasted time and less wasted product.
And while I am currently only using it with 5 and 10 pound batches, I see no reason why it wouldn't scale up.
So far I am very happy and very impressed.
updated by @michael-arnovitz: 09/15/15 15:10:18