Where to measure water temperature

ThatsMyCoffee.com

I've been thinking about adding a PID controller to my machine to increase and better control the water temperature in my Gastroback (Breville) machine.

Right now, I'm getting 65 to 70c and frequently the espresso tastes sour. After running the steam wand for about 30 seconds (which forces the machine to give full power to the thermoblock) I can hit 75c and most of the time, this problem goes away.

My question to the forum is: Where should I be checking this temperature?

I've been reading it in the (pre-warmed) cup. Should it be there? Or in the portafilter? Somewhere else?

Thanks,

Scott
ThatsMyCoffee.com

Koffee_Kosmo

Sour coffee is from cooler than the optimum temp of the water passing through the puck And yes everything should be hot Machine , PF , cups KK

ThatsMyCoffee.com

I guess I wasn't clear enough. I know the temperature is too low and needs to come up. The question is how do I know *how much*? Should I remove the PF and try to (carefully) measure it there?

derrilex

I was always under the impression that brew water at the puck should be between 91 & 93 degrees C. I would just run the machine and measure the water coming out of the brew head. Not 100 % accurate but more than good enough to see if you have a issue.

Koffee_Kosmo

ThatsMyCoffee.com wrote:

I guess I wasn't clear enough. I know the temperature is too low and needs to come up. The question is how do I know *how much*? Should I remove the PF and try to (carefully) measure it there?

The ideal temp for espresso coffee using beans that have reached 2nd crack is 90 to 93 deg C but can be in a band of 89 to 94 deg C There is a direct correlation to the correct brew temperature and the depth of roast To light a roast and greater heat is required with longer contact time The easiest way to measure the water temperature is with a bead/wire type thermocouple inside the locked PF KK

UNM

Hmm, I thought around 70c in the cup. Derrilex method of measuring brew water temp (KKs figures are good, but 90-95 as an approximation) is useful as cup temp is affected by other factors, so will give as close a guide as you can hope for unless you get access to a scace type device. If you have a small bead thermocouple you can drill a hole in a portafilter and place the bead at the base of the filter basket to get accurate temperature readings of real extractions Eventually, you will get to the stage you need to let your senses guide you, but measuring can certainly help set you on the right path and develop consistency.

ThatsMyCoffee.com

Ok, sounds like we're on to something here. I'll probably try removing the filter and running a temp probe up the spout of the locked PF first. Makes sense. After the machine has warmed up and then I'll run maybe 2 or 3 shots (as I've noted in the past that the machine needs this to reach a consistent temp.) Thanks everybody!