I will try that dose and ratio. I've been using 19gr with 36-38 gr out with a 8-10 second pre infusion for a total of 36-40 seconds.. It definitely gets to the end of the water supply in the pull. Your recipe would be more comfortable perhaps for the 800. I have a 18gr VST and Barista pro baskets. I will give them a go.

espressoerik wrote:An update -

I've confirmed this is in fact a temperature problem. Lowering the boiler to 240ºF fixed the issue, and so far, it appears I can operate around 243ºF which delivers about 200-202ºF water to the portafilter.

I do believe - and others will contest - that my 4,600 ft of elevation is the culprit. It's clear that using a boiler temp of 246ºF or more, at my elevation, the water coming out of the group is flash boiling - pretty much exiting the group head as steam. Using the 246ºF (or more), the group water temperature at the portafilter is at 204ºF or more. My water boils here at 202ºF

I have a new Pro 800 and here in Colorado, I am experiencing similar issues. This is not surprising to me though -- my last machine was a Synchronika, with the brew temp set to 200. When I lifted the brew lever without the portafilter attached, the water coming out would gurgle. At that temperature, water does not boil at 5k feet where I live. I spent hours on the phone with the technicians at Whole Latte Love, trying to figure out what was going on. I even ended up sending the machine to them, and they could not reproduce the issue. I am somewhat convinced that the elevation is the culprit, but I still don't understand how or why.

I've asked baristas in ski towns about this and never got a useful response. I am definitely not buying the "your beans are not rested enough" explanation.

In the end, I decided that the gurgle probably doesn't matter, as long as the temperature at the brew head is correct (which it was, according to an instant read thermometer). But I am curious about revisiting this conclusion now that I've got a different machine.

If lowering the boiler temperature removes your gurgle/frothing, is that even a good thing if it means your brew temperature is lower than you'd otherwise like it to be? In your case, the brew temp seems appropriate, but I don't understand why the elevation would cause less of a temperature drop between the boiler and the brew group. This is not when I experienced with my old Synchronika anyway.