Pulling 'true' doubles

Beginner and pro baristas share tips and tricks.
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dsc

#1: Post by dsc »

Hi everyone,

recently I've been struggling to pull a 'true' (50-60ml) double espresso from my double basket and unfortunately I cannot get anything good taste-wise or volume-wise. I'm working with a week old SO (Celebes Toraja), but had similar problems before with other SOs as well as blends. If I set my grinder (Mazzer Major) to give me around 50ml of liquid after around 30s it's rather watery, body is lacking and the crema drops down pretty quickly, not even mentioning that stream turns blond pretty quickly. If I set the grinder to give me a slow pour, with beading at the beginning and a thin brown stream I can't get more than 30ml of liquid before the pour blonds or starts channeling.

To top that my pours usually never actually 'swell' as seen on most NPF extraction videos. They simply stay thin as a mouse tail and stay that way throughout the whole extraction. The only moment when they tend to 'grow' and expand when forming the cone is when I open a new bag and run a couple of test shots to set up the grinder. After a day or two it simply disappears and I end up with thin rat tail like pours which don't want to form an actual cone.

Any ideas what I may be doing wrong? or is it simply quite hard to get a 'proper' double from 14g of coffee?

Regards,
dsc.

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another_jim
Team HB

#2: Post by another_jim »

Try grinding coarser -- Al Critzer's rule states the larger required the shot volume, the shorter the shot time should be; a full 50mL to 60mL shot should be done in the 20 to 25 second range. As with all rules, there are lots of exceptions, but this is the place to start.
Jim Schulman

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dsc

#3: Post by dsc »

Hi Jim,

thanks for the tip, that's what I've been trying, but for some strange reason I still can't get a 'proper' calm pour, ie. no sudden swirls in the cone, no dancing cone and no channeling.

Perhaps it's a good idea to post a video and I will try to do it today.

Regards,
dsc.

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dsc

#4: Post by dsc »

Hi again,

so here it is:
Yes I know it's too fast and I will try to set the grinder a bit finer, but this won't change too much speed-wise (I'm shooting for 20-23s tops). Usually I don't have such problems with channeling, but for some reason I got them this time when doing the video. The result was around 45ml of espresso, but I had to cut the shot a bit faster as it was going blond already. Taste-wise it's nothing special, good in a cappuccino, but as a straight shot I've had better.

Regards,
dsc.

Bertie Doe

#5: Post by Bertie Doe »

Hallo dsc

Did you complete that scace-like mod to your spare p/f? I was wondering if temperature may be an issue?

Bertie

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another_jim
Team HB

#6: Post by another_jim »

18 seconds is close to right for a lungo shot. The color is also about right. So the only thing that needs calibration are your expectations.

Try worrying only about the taste.
Jim Schulman

Bertie Doe

#7: Post by Bertie Doe »

another_jim wrote
So the only thing that needs calibration are your expectations.


Three days earlier Jim and that would have been in the running for quote of the year. Sadly, folks' attention span, won't carry beyond Thursday week :roll:


Bertie

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RapidCoffee
Team HB

#8: Post by RapidCoffee »

another_jim wrote:18 seconds is close to right for a lungo shot. The color is also about right. So the only thing that needs calibration are your expectations.

Try worrying only about the taste.
Good quote... but a 45ml double is not a lungo.* The video shot is too fast for a normale double, and the naked PF shows clear evidence of channeling throughout the pour.
dsc wrote:To top that my pours usually never actually 'swell' as seen on most NPF extraction videos. They simply stay thin as a mouse tail and stay that way throughout the whole extraction. The only moment when they tend to 'grow' and expand when forming the cone is when I open a new bag and run a couple of test shots to set up the grinder. After a day or two it simply disappears and I end up with thin rat tail like pours which don't want to form an actual cone.
This paragraph makes the coffee suspect. Are you sure it was roasted within the week? You have some very high end gear, so that seems an unlikely culprit... but it might be time for a good cleaning of both the espresso machine and grinder. That's my fallback plan whenever the espresso goes south.

* Assuming we're measuring mostly crema volume.
John

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dsc

#9: Post by dsc »

Hi guys,
18 seconds is close to right for a lungo shot.
Good quote... but a 45ml double is not a lungo.
I was just about to say that, 45ml in 18s seems to little for a lungo and that's why I've mentioned that the shot is too fast. I always thought of lungo as a longer normale, so I would say 70-80ml would be the expected volume.

I know the video shows clear signs of channeling, but 95% of my shots are channel-free. The temperature was 92*C measured on the group with an unsheated TC.
This paragraph makes the coffee suspect.
I would bet my Elektra that the coffee is fresh and was roasted recently. Besides the same thing happens with all other blends and SOs I've tried since I got the Elektra (including coffees from different roasters). I can of course grind finer and get slower pours (much slower than that on the video), but they only give around 30ml of liquid and I was really curious to try something different.
but it might be time for a good cleaning of both the espresso machine and grinder
Grinder was cleaned 3 days ago when I was switching to the Toraja from a blend and the group head on the Elektra was cleaned two weeks ago. The last backflush with detergent that the machine had was more than a week ago.

I've set the grinder to a finer setting yesterday and of course got a slower pour, but again less than 50ml of liquid. It simply looks like the machine won't deliver volumes bigger than 30-40ml without extraction problems. Or I'm doing something very wrong on the PF side of the whole thing.

Regards,
dsc.

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eastpresso

#10: Post by eastpresso »

When is the last time you changed your burrs? If you grind per shot - have you tried putting more beans in the hopper? I suppose the brew pressure is fine? It looks like the grind/distribution is off.