Portafilter Heat vs. Grinder Heat

#1: Post by **IMAWriter** » June 5th, 2015, 1:21 am

I've posed this question as an aside in someone else' thread a long while back, but wanted to see what the population here thinks.

My theory is that a super heated portafilter and its basket insert is at a temperature FAR above what a quality grinder such as a K30 Cario, K-10, etc would put on a 18 gram grinding session. 4 seconds on average for a K30 Vario grind of 17 grams, lets say. The grind is barely...if that warm in palm of my hand. Same with the Baratza Forte.

Next, I grind 18 grams directly into the HOT portafilter that was in the group for at least 20 minutes, wait 20 seconds, then dump the grind into the palm of my hand. It is SIGNIFICANTLY warmer. Now suppose I grind into the PF, quick distribution, tamp, then insert in the group...which is at maybe 91-92c. Let say I wait another 10 seconds after the boiler recycle. Even assuming the water is emanating from the HX, I HAVE to think the coffee cake in the PF/Group is more than significantly hotter than what originally came from the grinder.

This seems to mean that a bit of grinder heat means nothing. In fact, the recent thread regarding a sous vide bath to heat up the beans prior to grinding, and it's apparent acceptance as a good thing would again dispel, once and for all the notion that a wee bit of heat from the grinder is, in any way deleterious to the resultant pull.

Am I missing something? Wouldn't be the first time.

#2: Post by **ira** » June 5th, 2015, 2:12 am

Reading between the lines in the discussions about the Mythos one, it would seem that the biggest problem with burrs heating up is the required grinder adjustment change as the temperature changes during the day.

Ira

#3: Post by **aecletec** » June 5th, 2015, 4:03 am

Yep grinder heat is generally explained by industry people in my experience as a problem due to the necessity of changing settings due to the grinder heating up, not necessarily the coffee heating up... though, heat radiating up into the hopper is sometimes discussed.

#4: Post by **canuckcoffeeguy** » June 5th, 2015, 8:11 am

I single dose my K10PB and grind directly into my basket, which is kept outside of my portafilter. So my basket is room temperature when I prep and distribute.

However, I keep my portafilter locked in while my machine idles. So it's kept in equilibrium with machine temp.

Once I put the basket into my portafilter I do a light bottom tap to settle and then tamp.

I find I can prep and distribute better with a basket only approach, as opposed to grinding into a portafilter and then distributing.

How, and if, this approach affects my brew temps I don't know. But I'm consistent with my routine, so I think it's moot.

Unless a grinder is running full tilt, shot after shot in a cafe setting, I doubt heat is a major factor for grinders.

#5: Post by **baldheadracing** » June 5th, 2015, 10:27 am

The Colin/3fe Mythos presentation offered the tidbit that the design team preferred their espresso ground at temps well above room temperature: 35C to 55C. The sous-vide presentation and the microwave experiments are (perhaps among other things) raising the temperature of the coffee when it is ground; perhaps into the 35C-55C range. (As an aside, if you do RDT before microwaving, the coffee is going to come out of the microwave stinking hot

.)

I would consider grinding temperature and portafilter temperature as two different things, as two different things are happening to the coffee - one is the temperature where the coffee bean is being broken up mechanically; the other is the temperature before extraction. Too much or too little heat in either case is not going to be a good thing; how much is too much and how little is too little ... well

June 5th, 2015, 1:49 pm

Good stuff everyone.

I just have to figure if all the "machinations" happen inside 45 seconds..grind, distribute, lock in, pull the shot/ push the button/ flip the lever/paddle, whatever is done to initiate the shot, I can't see how too much bad can be done as regards heat, unless, as was said, the heat is EXCESSIVE.

#7: Post by **Mokko** » June 5th, 2015, 4:05 pm

I just upgraded grinders from a Mazzer mini to a Compak F10. The Compak runs a cooling fan and is a conical vs flat but...lots of differences. But another significant difference is the grinds are much fluffier. With my Mazzer, 20 grams was below the lip edge of the basket, with the Compak 20 grams is a heaping mound. Do you think grind temperature can impact the quality grounds? Stated another way, does a grinder that generates higher heat as it grinds, also promote clumping and adhesion of the grinds as a result of the temp?