I can pull somewhat acceptable shots with a single basket, it's hit or miss but i am trying to work with the WDT since my grind can be a bit clumpy (mazzer mini, domobar super). For some reason the doubleshot is IMPOSSIBLE for me no matter what I try, i almost always get a massive gusher with bad channeling indication around the edges. I tried weighing my coffee from 16 up to 18 gram, wdt leveling tamping, etc. I just had an autotamper show up today and thought this might help but it's just as bad using the autotamp. If i do not use wdt i think i get clumps that lead to channeling, if I use wdt when i take the cup out there is a gap around the edges and various methods to fill the gap such as wrapping on the counter before leveling, pushing with finger nsew or pencil. It's always the same a big gusher with a noticeable side channeling gap on the edge. I am not sure what else to try. I've gone through bag after bag trying a huge variety of things and I just get nowhere. Tag me as worst home barista in history.. sometimes I feel I'm like a 1 armed blind man trying to play golf. Maybe i'll try the fleth move, that should be a sight to watch..

Sounds like a coffee problem. How old are the beans, and how long before your shot are you grinding them?

Also, how old is the Mazzer...any chance the burrs are shot?


Grant

Well, i tried something different and it's working so far. I dose into the basket with the cup attachment, do my wdt only this time after i remove the cup I use the fatter than normal round pencil to push down on the top of the coffee stack from front to back sort of a gentle mush/mush/mush lightly pushing the grounds down, then i use the pencil to do a nsew leveling. Had close to 2 god shots in a row (my new autotamp may have helped a bit too). The wife was having a mouthgasm I just hope it wasn't a lucky fluke. I still have not attempted this on the double basket maybe tomorrow..

Well, looks like a got lucky, just pulled 2 more singles 1 probably would have been ok but i over-extracted it. The second blamo huge side channel. I think i have every aspect covered except dosing & pre-tamp. I have good beans, good grinder, right grind setting, consistent tamp with the autotamp, brew temp sussed, etc. My weakest link is when the grinds go into the basket and what happens after that. I may try WDT + that fleth move hmm... Got any suggestions hit me..

jeffg wrote:For some reason the doubleshot is IMPOSSIBLE for me no matter what I try, i almost always get a massive gusher with bad channeling indication around the edges. I tried weighing my coffee from 16 up to 18 gram, wdt leveling tamping, etc.

Try dosing less and grinding finer, e.g., 14-16 grams. Also confirm the brew pressure isn't wandering due to a faulty OPV spring as Randy reported:

Randy G. wrote:
The new spring, on the left, is much heavier than the original that I removed. The difference can be seen here, and compressing them between index finger and thumb reveals a great difference in compression force as well, with the new one being far stiffer.

Replacement is a simple matter of unscrewing and removing the adjustment screw, removing the old spring with a small tweezer, and replacing it with the new spring. Screw in the adjuster and Vito's your barista (Bob's your uncle?).

Once I had it all back together I inserted the blind filter and readjusted the OPV. I found that the new spring made it MUCH easier to adjust. The original was very touchy and the smallest adjustment made a large difference. The new spring was very linear in its adjustment and finding the desired setting was a very easy matter. before closing it up I turned the pump on and off a few times and every time the pressure gauge hit the exact pressure I had set.

Thanks for the info. I a pretty sure i have the right spring as my pressure never wanders, with the blind filter it hits the exact spot each time and holds steady. I suppose I could check but it doesn't look easy getting to it. As for dosing less and grinding finer that would likely have the grounds mostly below my basket edge so how do you distribute the grounds when it's like that? Do you just tap the basket around until it's level then tamp? Thanks!

well just pulled 15 more shots trying all manner of settings techniques etc, how many good ones did I get? 1 and barely good. When i tried to replicate what I did on that one shot I got a 5second gusher. I am now giving up and will not touch my equipment again until I have formal barista training. I'm currently trying to find a 2-3 day course of somekind. Very low spirits right now ugh.

jeffg wrote:........As for dosing less and grinding finer that would likely have the grounds mostly below my basket edge so how do you distribute the grounds when it's like that? Do you just tap the basket around until it's level then tamp? Thanks!

It sounds like you are using too much coffee. That can be a real problem. Try about 14-15 grams. Don't fill the PF.

If you have a gram scale, try weighing some GROUND coffee. Start with about 15 grams. Then pour the coffee into the portafilter. This will give you a good idea as to how much to use.

In daily use, as you grind, move the portafilter about to get the coffee distributed as evenly as possible while you are grinding so that further distribution is not very necessary. Once you have the correct amount, shake the PF about a bit to level as much as possible. You can use the WDT at this point if you wish. At this point, if the coffee seems uneven I will tap the PF STRAIGHT DOWN to pre-compress the grounds, or if the difference is slight, I will just jiggle the PF to level. Now tamp and lock. Remove the PF before beginning the pull. The coffee should NOT have contacted the screen.

You can also do the nickel test- place a nickel on the coffee and then lock the PF in place again. There should be no more than the slightest indentation from the nickel. if the coffee was disturbed beyond that, you used too much coffee for that basket.

Sorry to hear you are having so much trouble. I swear that several, untrained home baristas have pulled great shots first time out on my Vibiemme, so let's see if there is something amiss.

Please review http://www.home-barista.com/forum...p-guide-t3113.html

By side channeling, I assume you get a big blond gush out of one side of the basket

- the machine should be on for at least 45 minutes, with PF in the group
- boiler pressure ~1bar, 0.9 to 1.1 is normal
- when you lift the lever with no PF, there should be steam for just few seconds, then plain water
- brew pressure about 10.5 on a shot and should not vary, except a little with the heater element
- coffee should be from 4 to 8 days from the roaster drum

If you flush to rinse the screen, do it just before you pull the shot. This will prevent thermosyphon stall.

The most common problem I see with noobs is an uneven tamp. Use your fingers as a gauge around the tamper and make sure the tamper is level. IMO, the AutoTampers apply WAY too much force. The one time I tried them, the missus asked what all the clacking was about. A light level tamp is all that is necessary.

Try 15g and level just as Randy said. Adjust the grinder for 60ml in 30 sec.

jeffg wrote:I think i have every aspect covered except dosing & pre-tamp. I have good beans, good grinder, right grind setting, consistent tamp with the autotamp, brew temp sussed, etc. My weakest link is when the grinds go into the basket and what happens after that. I may try WDT + that fleth move hmm... Got any suggestions hit me..

Still think it is your coffee....what is the roast date of the beans you are trying?

Sounds like exactly what happens if I use stale beans....no amount of fiddling with distribution, tamping etc. helps.

With your Mazzer grinder and a 14g dose with fresh beans, you can practically "toss" the grinds into the basket without ANY distribution and tamping and get a decent shot.

http://www.home-barista.com/forum...luation-t4501.html

If you have gone to all that muss/fuss and are still getting channeling, it has got to be old beans.

Grant