My morning-espresso tastes thin, bitter and under-extracted. Then in the afternoon, it transforms and becomes much thicker, fuller and just better tasting. I have noticed that especially on sunny, dry days, the shots are very good, while on humid days they are mediocre and especially in the mornings, the shots are never good. Of course I change the grind according to the humidity, but no matter how fine or coarse the grind I never seem to be able to nail it in the mornings, while both the fast and slow poors always turn out quite good in the afternoons.



Has anyone else experienced this, and if so, what could be a solution?

klino wrote:My morning-espresso tastes thin, bitter and under-extracted.

Bitter is usually a sign of over-extraction. Sour is the flavor of under-extraction.

Do you leave your machine on all day, turning it off at night (or evening)? If that's the case, perhaps your machine isn't sufficiently warmed up? Most machines need at least 30-60 to properly warm up. Just reaching brewing temperature isn't warmed up.

klino wrote:My morning-espresso tastes thin, bitter and under-extracted. Then in the afternoon, it transforms and becomes much thicker, fuller and just better tasting. I have noticed that especially on sunny, dry days, the shots are very good, while on humid days they are mediocre and especially in the mornings, the shots are never good. Of course I change the grind according to the humidity, but no matter how fine or coarse the grind I never seem to be able to nail it in the mornings, while both the fast and slow poors always turn out quite good in the afternoons.



Has anyone else experienced this, and if so, what could be a solution?

I experienced the opposite direction last Saturday and was going to post here. No change in beans, no change in grind, no change in shot parameters as far as I could tell. I was pulling shots for friends from 10am until 2pm, the morning shots were stellar, fruity up front with a bit of bakers chocolate in the end. But after noon they were bitter and I never got back to the morning shots.

Only the environmental temp changed during that period, humidity stayed pretty much the same.

This is on the single group commercial lever so the only thing I can think of is that shot temperatures were rising during the day and I should have tried better to mitigate that on my machine.