Does temperature loss from dosing basket outside portafilter matter?

#1: Post by **CaliforniaJed** » January 9th, 2011, 2:06 pm

When one grinds/doses directly into the basket and then inserts the basket into the portafilter, isn't the basket temperature lower than ideal? (Or is this temperature difference immaterial?)

Thanks for your thoughts.

#2: Post by **RapidCoffee** » January 10th, 2011, 12:22 am

You certainly want to avoid dropping the grouphead temperature, which would in turn lower the brew water temperature. But the mass of the filter basket is relatively insignificant. You are better off minimizing the time that the portafilter is removed from the grouphead. Dosing directly into the filter basket, as you describe, is the best way to accomplish this.

#3: Post by HB » January 10th, 2011, 6:45 am

I posted this in Can hot portafilter burn the coffee even before brewing?

HB wrote:Years ago I did measure the temperature difference between the top and bottom of the puck for hot/cold baskets:

The distance between the lines indicates the cold/hot basket delta; the distance from the 0 axis represents the top/bottom delta. It shows that indeed cold/hot baskets do have a measurable effect on the first seconds of the delta between the top/bottom, but the effect falls below the boiler's natural temperature variance shortly thereafter (measured on a La Marzocco Linea without PID controller). That said, I don't consider the above chart the last word on the matter, as it was hastily created from just a few trials back in 2004 in response to a discussion on CoffeeGeek.

John raises a point that I had not considered: Is the heat loss difference between cold/hot baskets smaller than the portafilter/hot basket heat loss while dosing directly? I haven't measured, but I bet the answer is yes for all except ultra-fast baristas.