Peter:
FBM has developed a response to your concerns about interrupting the flow of chocolate when depositing into molds.
In most tempering machines that use augers to transport the chocolate through the pipe the flow of chocolate is controlled by starting and stopping the auger. When this happens repeatedly over a short period of time the dwell time of the chocolate in the pipe changes, which can change temper. Plus, because the flow of chocolate is not constant the rate of melting in the bowl is not constant, leading to over-crystallization.
FBM offers, as an option on some of its machine, a pneumatically-controlled doser. When installed, a pneumatic valve (i.e., one that is operated by compressed air) is installed at the top of the tempering pipe. When closed (the default position) the chocolate is diverted down a separate pipe into the working bowl. When the dosing function is activated, the valve opens and the chocolate flows to the mold. After the desired time, the valve closes. In other words, the tempering auger never stops turning and the flow of chocolate is never interrupted. This design eliminates virtually of the drawbacks associated with controlling the flow of chocolate by starting and stopping the auger.
I don't disagree with you about getting a machine that is larger than absolutely necessary, because parameter that affects the consistency of temper include how rapidly the amount of chocolate in the bowl changes and how full the bowl is. It's much harder to maintain temper when the bowl is one-quarter full than when it is full and when you're emptying the bowl faster than the nominal tempering capacity. (FBM's rule of thumb is that the tempering capacity/hr of a machine is 3x the bowl capacity - assuming the bowl is kept full.) However, in my experience, people tend to under-buy capacity because of the expense involved. Having an outboard melter that automatically keeps the working bowl of the tempering machine is a great option to consider if high throughput is required.
FBM also offers three-zone tempering on some of its machines. This can help quite a bit in fine-tuning and maintaining the consistency of temper over the course of work shift.
Of course, the chocolate(s) being used also affect the ability of a machine to reach temper in the first place as well as maintain temper over time.
Not surprisingly, the location of the thermocouples used to measure the temperature come into play, and it is possible that a thermocouple is not properly adjusted within the flow of chocolate. This can lead to difficulty in reaching and maintaining temper.
And, finally, there are differences in software that can account for some of this. FBM has, on its larger machines, a "soft" and a "hard" tempering curve. This refers to how aggressive the chocolate is cooled. In the soft setting the chocolate is cooled more slowly. In the hard tempering setting the chocolate is cooled quickly until it comes to within a set number of degrees above the temper point, and then cools more slowly. Some chocolates do not seem to work well with the more aggressive cooling cycle, so that's why the operator is given a choice.
Yeah, it's a lot to learn, but as I said earlier, the machines are not artificially intelligent. They only do what the operator sets them to do.
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@DiscoverChoc
updated by @clay: 07/25/16 19:31:10