ira wrote:One the boiler gets to temperature, it will stay more more temperature stable with a PID. It may also take slightly longer to get to temperature because the PID will slow down the heat as it approaches the set temperature.

One thing I'm considering is the copper coil wrap that some have done on the Gaggia Classic. Of course there's not much room, so you'd only get maybe three 1/4" or two 3/8" coils around it. This would provide @ 8 grams of significantly preheated water, which would make temps even more stable. And since I really don't do milk drinks, the small hit this would make on steam would be irrelevant.

My concern (aside from messing with a perfectly functioning unit) is that the soft copper spec is 150 degrees. Wrapping it around a vessel that reaches 210+ F might compromise its ability to handle 9 bar pressure. So I'm in no hurry. Research and testing are needed.

EDIT: one possibility for the copper coils is to keep them 1/8" from the boiler. That way they absorb much of the warmth radiated by that boiler, without becoming leach-radiators themselves.

EDIT2: 3/8" Type L tubing, three wraps, would fit - and would provide more than 14 grams preheated water. And after some research I'm finding the pressure won't be an issue. Temperature stability would essentially become a non-issue. I'm pretty certain I can get it installed without disassembling the whole thing; I'll pre-coil it and then sorta twist it in counterclockwise.

EDIT3: upon further research, the copper coils cause lots of noise as they expand and cool down. I don't need the extra noise in my kitchen. So that idea is abandoned.

baldheadracing wrote:With the PID on the Silvia, my end-of-shot brew water temperature is two/three degrees F cooler than the beginning-of-shot temperature (measured on a Scace).

Tonight I got my non-PID ViaVenezia to start pre-infusion at 199 degrees, climb no higher than 204, and then fall no lower than 192 by the time the shot was done. That was a function of managing flow. My usual output is what I'd estimate (since I don't use a scale) as @ one to 2.5. So I scaled back the flow a little; lower flow throughout the shot, and then NOT boosting it to maximum flow at the end. The 'ready' light on the Brew button stayed lit throughout the shot. Ratio was probably 1:2 or slightly lower. The flavor profile was very similar to my usual, just more concentrated and slightly sweeter.

Temperature range not quite as focused as your PID, but well within the parameters of desirable espresso temperatures. The temperature gauge has proved to be nearly as good an addition as the dimmer. The guesswork has diminished, replaced by knowledge and method.