Aloha. Looking for some advice on naked portafilter extraction. Been using Silvia and Rocky for a fair amount of time and have time and volume pretty much dialed in with a 16g double. Coffee is fresh roasted weekly. Given these variables and a modified WDT with 30-40 lb tamp, my shots start out pretty but I still get blonding and then spitting halfway (15 sec) through the shot. I thought that the most likely explanation at this point might be high brew pressure and I've been progressively backing out the OPV spring. I'm at 2/3 of a turn and the shots definitely taste better but the blonding and spitting continue. I'm wondering I use a Synesso double basket with the 16g shot but after tamp, there is quite a bit of headroom left between the puck and the shower screen. Would basket depth potentially be a factor ?

Mahalo Dan. So I took the blonding poll and I guess I failed miserably - if I were to cut off my double shot at the approximate time that most voters recommend, I think I would get no more than 1.25 oz and the shot time would be quite short (15-18s). Will take some video over the next couple of days (also I apologize - i should have searched and posted under the same post from august). Shots have been tasting better since dialing down the pressure - less frequently sour.

How old is your setup and when was the last time you replaced your Rocky Burrs? I had this same problem, then got new burrs and viola!!

The Rocky burrs do not seem to last very long....I needed to change mine every 12-16 months when I had it.

One way to tell if they need to be replaced is if you keep having to dial the grinder lower than when new...

-Mark

I'm not sure if this will help but here's what I did when I complained of my shots blonding early. I reduced the shot dose to 14gm (and I used a scale to weigh every shot which I still do). Reading a post by another_jim, I was inspired to try dosing 14gm and found less channeling, better consistent shots.

Thanks everyone - my burrs are indeed likely worn - although when I dial the grind down one more notch I can produce close to 2 oz in 30 secs but the blonding doesn't seem to happen less quickly. Will replace and re-evaluate as well as play with lower dose (and slop fix). I note that my shots seem to take 10-20 secs to settle and then form quite a layer of crema (kind of like watching a freshly drawn Guinness) so I think that I may still need to back down the brew pressure a little more. Also I typically roast 3-4 days before drinking. Is it possible a longer wait period would yield less quick blonding ?

MUTTS wrote:Also I typically roast 3-4 days before drinking.

Try a quality, known good espresso roast.
No offense, but maybe your home roast is the problem.

No offense taken. Will start looking around the web - Kona coffee may have a good repuation but not so much about quality Hawaiian espresso.