I have been playing with some temperature control on my Gaggia Factory for the past month, and have something that I have found to be very useful, repeatable and most importantly, improves my shots.

We know that one of the main difficulties with most levers is the tendency to overheat the water (since it needs to pressurize) and consequently the grouphead. People have tried wet towels, time, sprites of water etc to cool the head. What I found effective is a pseudo water dance like is used on HX machines. The trick is using it in conjunction with the boiler set at the lowest possible setting of pressure to allow the water to reach the head. I found this to be right about 10.5 psig or 0.7 bar. I achieve this by letting the system heat up and equilibrate as normal, and then flipping the unit off as I start my shot prep. The pstat for mine is set at about 1.1 bar. I know I can adjust it, but this is working.

Anyway, I turn off the machine and start my prep.

1) Remove and dry my PF.

2) Start the first "Dance". I lift the lever until water starts to come forth. I hisses and dances. I do this two or three a couple seconds apart. This seems to be the important part. A straight flush doesn't seem to cool the head down as well as getting some water onto the head and letting the steam produced carry the heat away. There is more energy carried away in steam then in water. Once it stops hissing, I continue on.

3) I grind directly into my PF, settle, tamp and check my pressure gauge. Virtually always it is right at 10.5 psig. If not, I give the head another quick shot of water by lifting the lever. There should be no hiss of steam this time.

4) From someone else's suggestion here, I then lift the lever just shy of water coming out, load and lock my PF, raise the lever all the way and apply a touch of pressure (under a pound, hand weight basically). I continue to raise the lever as water saturates the puck over the next 10-15 seconds. This seems to get me a fully saturated puck and maximum volume (each time I lift it, I feel a tiny hit of water filling the void, but not enough to disrupt any seals).

5) I then pull the shot for a leisurely 25-30 seconds if possible.

That is it. Since starting this, I have successfully pulled consistent back to back shots until my boiler was empty. 7 shots total IIRC, and not a single one burned.

And as a lot of procedures here, it sounds way more fussy than it really is. And yes, it "wastes" a bit of water, but I would rather have 7 great shots then 2 great, 4 mediocre, and 4 bad ones