nuketopia wrote:Here's what I've found over the last couple years:
1. Frozen beans will "grind finer". Same beans, same setting, but straight from the freezer will pull a slower shot.
2. Pre-heated beans (125f bean temperature) will "grind looser". Same beans, same settings will pull a faster shot.
This is interesting. I've consistently find that my shots in the afternoon tend to pour a bit faster than those in the morning, with the same settings on the Monolith.
I live near Denver, and it tends to be cool at night, and warm up during the day. So for me, during the summer, "room temperature" in the cabinet where my coffee is stored is typically around 69-71 degrees in the morning, and ~75 degrees in the afternoon (with air conditioning running). In the winter, mornings might be 64-68 degrees (heater running, but still ramping temperate throughout the house), and 68-70 or so in the afternoon. So in either case, up to a 4-5 degree difference in ambient temperature.
I find shots tend to run maybe 2-3 seconds faster in the afternoon for the same volume, give or take. Not always, but as a general rule, this seems to be fairly typical.
I've always assumed it was a humidity difference (although I don't have any tools to measure this inside). But temperature could be it instead. If it was the metal in the grinder burrs expanding/contracting, I would expect colder parts to contract, and thus making a coarser grind when it's colder, which is opposite to what I see, so this is likely not it.
So I'm thinking perhaps it's the beans themselves being cooler/warmer causing some of the difference.