Coffee froths out of bottomless portafilter

Help Support Steer Planet:

ngotham93nd

Member
Joined
Aug 19, 2015
Messages
6
Hi coffee people (you guys, not the old place in Portland),

Two issues, perhaps related: 1) I've pretty consistently seemed to have an issue of early blonding and lots of frothing/big bubbles after about 15–20 seconds from my bottomless portafilter. 2) We just installed new burrs on our grinder, but the finest setting before they chirp no longer is enough to choke the machine. It had been on the old burrs we bought the machine with.

More details:

Machine: Saeco Aroma; naked portafilter
Grinder: (90s?) La Pavoni Zip base
Coffee: various; 1-10 days post-roast
Dose: 16-18g
Time to 35g of brewed coffee: about 25 sec.

I always pull a few oz through first. The machine has been on usually 30-min at least. I grind right before dosing and tamping. I think I'm tamping 30-40lbs.

Shot description: usually drips gather in the center; dark brown stream in middle; goes to tiger striping; then, about 15 seconds or a little later the stream becomes a large cone and blonds; at worst big bubbles froth out of the whole bottom of the basket. When I check the puck it seems like there is probably some channelling, but not every time this happens.

So volume over time seems right (aiming for ristretto). That said, I've always (6 mos.) had some issue with the stream growing to a cone when blonding. Oddly enough, I got superior results on the old burrs we bought the grinder with, though only when I used the finest settings and tamped quite lightly – often 50 seconds for 1–1.5oz. Cream was okay (maybe a bit dark). Now, with the new burrs the FINEST setting and firm tamping yields that volume over about 25 seconds, but large cone and poorer, thinner crema.

Did we buy bad burrs? They feel sharper to the touch, at least. Am I missing some channelling? Other thoughts?
Thanks for any help

Tag : hat oc cho
 
Top