Hi. So, I dialed in a blend and it was great. Then I used it up and had to pull some shots of the same blend but roasted a bit different (much longer ramp up to development) with someone else. I had to pull the shots 20hrs or so post roast, and they were pretty raw. I had much more spritzing than normal and my pours didnt keep a nice cone shape, opening up too fast, yet they were pouring slow and had about 10% less volume after completing a pull-which on my pavoni is normally from 28.5-30g in one full pull depending on preinfusion technique. I ground coarser and never got it right despite some 7 shots. I was also ramping up pretty fast after preinfusion, trying to keep a tighter stream. The shots were really High and heavy on the senses-undrinkable really, just alot of unpleasantness in all directions.


My theory is that Despite a 10 second 1bar preinfusion some of the puck was not evenly saturated. This would cause the decreased volume. Also, with a sudden 9 bar the wetter portion flowed faster and caused for spritzing and for the puck to either fracture or the flow to become uneven. If true I was progressively exacerbating the problem rather than fixing it.

Thus, I suspect that a finer grind and a slower ramp up-say 5bar for 10-15 seconds then 9- it would have alleviated the problem. I have pulled shots early before, but never tried to dial in such a fresh roast.

Any of you guys have a similar experience or are fresh roast not normally the cause of such problems?

day wrote: Any of you guys have a similar experience or are fresh roast not normally the cause of such problems?

Sounds like every sign of a too-fresh roast. Time is your best (most consistent) cure.

Pre-grinding the coffee fifteen minutes or more before you use it can help if you have to use too fresh coffee.

If I'm using something really super fresh, I'll grind it before even turning the machine on and then do a much longer than normal preinfusion. Can make a shot fresh out of the roaster that way. Isn't as good as it will be in a couple days, but it's decent and gives somewhat of an idea what to expect.

Too fresh? I think I would adjust dosage and grind, starting with adjusting the grind first...I recently bought a digital scale and using it has opened my eyes. What I learned is that coffee density, either ground or as beans, can't be determined by the naked eye, and that volume doesn't equal weight. Further, grind density is directly related to how finely the coffee is ground. I would think freshness to be directly related to flavor, and not to the flow rate

Post by trees » Sat Feb 27, 2016 9:28 am
Too fresh? ... I would think freshness to be directly related to flavor, and not to the flow rate

If the coffee is outgassing copious amounts of CO2, as a too-fresh coffee would, it would certainly affect flow rate.

I've done the pre-grinding for cuppings and occasional brewing. I find it works somewhat ok on manual levers that I can control the flow thru the puck but it's not as useful for anything with a pump or heavy spring.

Andy wrote:If the coffee is outgassing copious amounts of CO2, as a too-fresh coffee would, it would certainly affect flow rate.

Ok, I'll buy that it may, or could, affect it to some degree, but it wouldn't have nearly the influence that the grind would have, would it? An adjustment in the grind changes the flow rate while allowing for copious amounts of crema, wouldn't it? I can't remember ever having too much crema. Probably should make a distinction here, I'm using manual lever machines. I think that having a declining pressure, and the ability to control that decline, is pretty important, but let me add that I've never used an automatic. Now let me add, I don't have a home roaster. The closest I've come is buying coffee from my local micro-roaster that was still warm and just bagged. They attempted to discourage me from buying that stuff, saying it was "too freshly roasted, and needed to degas". I thought at the time that it was more likely they were trying to get me to buy coffee that was a couple days old already, well, because it was a couple days old already....

This is all thought-experiment territory on my end, so take that into account, by all means. But consider: You are making espresso -- brewing under pressure -- while CO₂ is trying to escape (being forced out of the ground coffee by the brewing process). I don't see how that could not interfere with the flow of water through the puck. I don't think your vendor was trying to con you.

edit: duplicate post deleted