I bought some Tanzania Peaberry from a local roaster. So far, I've pulled 4 doubles with it (2 doubles per day), and had the same strange experience on each day. The morning shots flow so easily that I'm tempted to grind finer. The afternoon shots nearly choke the machine. I use the same weight of ground coffee each time. I have not adjusted the grinder. I tamp until the top of the tamper is level with the top of the basket, so I assume the force has been the same. I always fill the boiler before I use it.

I don't know what the difference could be--the relative humidity? It has been cool enough that I've had the air conditioning off. Thoughts?

Heilmittellehre wrote:I bought some Tanzania Peaberry from a local roaster. So far, I've pulled 4 doubles with it (2 doubles per day), and had the same strange experience on each day. The morning shots flow so easily that I'm tempted to grind finer. The afternoon shots nearly choke the machine. I use the same weight of ground coffee each time. I have not adjusted the grinder. I tamp until the top of the tamper is level with the top of the basket, so I assume the force has been the same. I always fill the boiler before I use it.

I don't know what the difference could be--the relative humidity? It has been cool enough that I've had the air conditioning off. Thoughts?

You're saying you're tempted to grind finer but you don't?

Probably residual grinds have overnighted in the grinder, making the morning espresso flow faster. I would surmise from your screen-name that you are a devotee of sleep, and the grinds have spent a long restful night in the grinder chute? The grinds haven't had as long to go stale by the time the afternoon rolls around, resulting in a slower flow.

You're saying you're tempted to grind finer but you don't?

Right. The morning shot makes me think I should should grind finer; the afternoon, coarser. I have not adjusted the grinder.

Probably residual grinds have overnighted in the grinder, making the morning espresso flow faster.

Maybe, but I remember this happening the first day I tried the new beans. I had vacuumed out the chute and the grinder to remove any leftovers, so the first shot should have been as difficult as my afternoon shots. Also, it's a doserless, so I don't think that great a percentage of the grounds could hide out in the machine. I'm sure that a gram is there, but that's about 7 or 8% of the total--but maybe that's enough to change things radically.

Since I'd be the first to admit that I have a sieve-like memory, I'm going to try a double experiment tomorrow. I will grind some coffee and put it aside for use in my afternoon shot. Then I will grind for my morning shot. If your hypothesis is correct, I should have a reversed experience (i.e., morning shot should be a near-choke, and the afternoon an overly-easy pull).

The things I do in the name of science....

Don't grind and set aside. The coffee will be super stale. Grind a couple of grams in the morning and discard. Ditto in the afternoon. Consistency should improve markedly.

See Poll : One Shot Grind Remnants

So far, staleness seems to be the culprit. This morning I first ground some that I didn't use and then ground for the shot. It definitely required force to pull the shot. Maybe not as much as the afternoon shots required, but a big improvement over the previous mornings' shots.

I am going to try to pull a shot with the initial grounds (grindings?) from this morning, if only to make it more certain that the staleness is to blame. It might be a sink shot. On the other hand, I'd be the first to admit that my developing espresso palate might not be sophisticated enough yet to mind.

Spoke too soon. My afternoon shot was made with about 50% "stale" grinds (i.e., the ground coffee I said I was going to set aside in the morning). It was nearly impossible to pull the shot when it should've been extremely easy. Other thoughts?