Shot Inconsistencies (and Challenges Dialing In Dark Decaf Espresso Beans)

JHCCoffee

Hi All

I have been having challenges dialing in a decaf dark roast espresso bean. Any suggestions are welcome. The following is from a log I kept over 2 weeks, if you cannot sleep and welcome some tedious reading:

15 Gram IMS Basket on Lelit Elizabeth with With IMS Precision Screen (and with a larger grind dial modification, for more precise grind setting). Note: clockwise (from 0 towards 9.9 or less) is finer; counter clockwise (towards 0.1 or higher) is coarser.

· Shot 1 - 13.5g in, 20.0g out, 11 second bloom pre-infusion, using a “9.25” grind setting on a Eureka Mignon. Ran 48 seconds, including the pre-inf. 8.5 bar pressure. Acidic taste, thinner (not fuller body/mouthfeel). Temp 95C. “Burnt” taste.

· Shot 2 - As above, 9.5 dial setting (2.5 tick marks coarser). Abit more balanced, but still burnt taste.

· Shot 3 - As above, 9.5 dial setting, no pre-inf. Decent balance (of acidic vs sourness), but still thin body. And ran surprisingly slow (45 seconds).

· Shot 4 - 13.5 in, 20 out, 6 second bloom pre-inf. Decent strength, but abit sour. So assumed that it is under extracted.

· Shot 5 - As above, but at 9.6 grind and 8 second bloom pre-inf. Ran 42 seconds.

· Shot 6 - As above, which ran 41 seconds.

· Both Shots 5 and 6 had sour notes (just a tad, but they were there). Tasted abit better in cappuccino, but I have made better tasting drinks than this!

· Shot 7 - 13.5 - 26.0 (by accident) - more balanced, better extraction (more interesting flavours, but thinner body)

· Shot 8 - 13.5 - 25 in 45 seconds, with 8 second bloom pre-inf. 9.6 grind. OK balance between sour and bitter, but I do wish I could get more sweetness. And no complexity.

· Shot 9 - 13.5 - 26.0 with 9.8 grind. 8 second bloom pre-inf. Faster flow than shot 8. Balanced, maybe a tad acidic. No complexity in the shot, but detecting some in the cappuccino. So extraction is likely up, due to longer shot.

· Shot 10 - 13.5 in 39 seconds with 0.0 grind (a tad courser). Thought it would flow faster than this. Now getting burnt, ashy, burn’t bitters, likely due to higher extraction of these dark beans.

· Shot 11 - 15.0 - 29 in 41 seconds, incl 8 sec bloom pre-inf. at an even course 0.5 grind. Balanced shot with a somewhat thicker mouth feel (than the prior shots). No burnt or ashy tastes, but no other complexities. Flow looked a little uneven and the top of the puck had some holes. Taste in cappuccino - more body, less extracted complexity. Perhaps there was not sufficient headroom in this shot.

· Shot 12 - 14.0 - 27.5 with 0.0 grind in 32 seconds, including 8 second bloom pre-inf. A tad sour.

· Shot 13 - 14.0 - 27.0 in 38 seconds at same (0.0) grind, including pre-inf.

· Both shots 12 and 13 were a tad thinner with less body. Better taste in cappuccino than the Shot 11 with 15.0 in- 29 out (i.e. more extracted flavour) but less body. I’d like more body.

· Best shot of the 13 shots was Shot 9 (13.5 - 26.0 at 9.8 grind with 8 second pre-inf).

15g IMS Basket with Lelit Screen

· Shot 14 - 13.5 - 26.0 in 30 seconds with 8 second pre-inf, at 0.2 grind.

· Shot 15 - Same as above

· Both shots had weak strength, not much body and not much complexity. But not sour or bitter.

· Shot 16 - 13.5 - 25.0 at 0.0 grind in 40 seconds (incl. 8 second bloom). Still weak strength and insufficient complexity.

· Shot 19 - 13.5 - 26.0 in about 45 seconds. Still weak strength, but some flavour complexities are emerging.

· Shot 20 - 14.5 - 26.0 in 36 seconds with 8 sec bloom pre-inf. Abit more body, but less flavour extraction. Still, a semi-decent shot.

· Shot 21 - 14.0 - 27.0 in 37 seconds. Abit less body (than Shot 20) but a tad more flavour (i.e. complexity). (When I say flavour I mean complexity).

· Best shot of this series is Shot 21.

· Best shot of this and the prior series is Shot 9. But still a 7 out of 10 (10 being best), on my taste scale. I’ve never poured better than an 8 (I am hard on myself, when I score).

A Completely Different Approach (Shorter Shots at 1 to 1.5 ratio, with a coarser grind). Using the 15g IMS basket and the Lelit Screen. Varying temps (see below).

· Shot 22 - 14.0g in, 22 out in unknown time. Grind setting at 0.5. Temp at 93c. The shot was abit sour. However the taste in cappuccino had good strength, good length and even a a touch of complexity. If I could get this taste, but eliminate the slight sour note that would be great! As per the next shot notes, I could not repeat this shot, let alone eliminate the slight sour note.

· Shot 23 - 14.0 - 21.0 at 94 C (up from 93C). Ground a tad finer at 0.3. Was hoping to get more extraction and eliminate the sour note. Shot taste declined from Shot 22. Less body, less complexity, less length and a tad acidic. So I thought that I went to far along the extraction scale and backed off on the next shot.

· Shot 24 - 14,0 - 21.0 in 35 seconds with 8 second bloom pre-inf 0.3 grind; 93 C temp. Sour shot!

· Shot 25 - 14.0 - 22.0 at 0.5 grind at 94 C. Did not note the time. Even more sour than Shot 24.

· Shot 26 - 14.0 - 21.0 at 9.8 grind. Still the same sourness! *** *!@#

· Best shot of this series (and best of all three series) was Shot 22. I liked the mouthfeel and the body and the complexity, but it had just a tad of sourness. Moreover, I was unable to repeat it.

· Note: I am more often that not seeing some puck fracture, and the occasional puck hole. Is my puck too thin with this basket, for a dark roast?

The Next Series (Just Started) - Back to an 18.0 IMS basket and the same Lelit Screen

o Shot 27 - 17.0g in, 25.5 out with 0.4 grind. At 93.0C. Way too slow.

o Shot 28 - Attempted 17.0 in, 25.5 out at 93C, with 0.8 grind (coarser), but the scale battery died and it ran too long.

o Shot 29 - 17.0 - 26.2 or so (using an older, less responsive scale). Still too sour and too thin.

o Gave up and will try again tomorrow.

Any Trendlines From The Above?

I am unable to find a trend line in the above, that would point me in the right direction. It could be that a dark roast bean (that is frozen and ground from frozen) needs a thicker puck, or it might fracture. I am not sure if I am right or wrong about that. Also, not sure whether it is a good idea (or not) to grind dark roasts from frozen? Am I creating too many fines?

I also noticed that my water flow (from the grouphead) is 180 ml in 30 seconds, whereas I read that it should be 200 to 280 ml (say 240 midpoint). Increasing the BAR pressure would increase the flow. If this is a linear relationship, then I would increase the BAR to 11, by adjusting the OPV valve. Is this part of the problem? But I worry that 11 Bar would be too high; I do not wish to damage Elizabeth.

Next steps: I vaguely remember reading somewhere that too low pressure can create shot inconsistency. Additionally, a somewhat higher pressure will allow greater water flow, and will also extract more. So I might try increasing the BAR pressure to say 10. Any other broad ideas? It would be great to enjoy a great espresso shot or cappuccino, more than once or twice in 30 shots !!

And … my apologies for the long long post.

With some frustration!!! JHCCoffee.

LMSC

JHCCoffee Wow! That’s too many for a day. I wouldn’t do that.

The decaf requires a lower dosage than the normal - I normally dose 1-1.5g less.
You can keep the same temp that you normally would
You need to grind finer than the standard coffee.
93C - 95C seem a lot for the dark decaf. Try losing a couple of C and see if you like the shot. I would drop 1C at a time and won’t hesitate to go to 89C.
PI time of 5-6s and not more than 10s. It’s a dark roast, you don’t want a longer PI IMO.

Based on these, I would try shots 3, 9 and 21 plus any shots you liked. Please don’t over do it on a single day. You can try your experiments over a few days. Please try and stick to a bag until you are happy with the result.

BTW, I prefer 1:2 if medium dark/dark.

Rob1

JHCCoffee Any Trendlines From The Above?

Sounds like they’re all under extracted and you just about manage to get some kind of normal extraction at a 1:2 ratio (e.g 18%). Burnt taste can be fines or channeling because of how fine you’re grinding. If you want a coffee with thick gloopy body then buy one that will deliver that and extract it properly. Very much sounds like you’re trying to force it with the ratio.

JHCCoffee

LMSC Wow! That’s too many for a day. I wouldn’t do that.

Thanks LMSC.

Too funny 😂. They’d be clawing me off the ceiling 🤪, if I did that.

This was a log that I’ve kept over a couple of weeks: I only drink 2 shots a day on weekdays, perhaps 4 on weekends. All shots were from the same 2 lb bag, which had been divided into individual vac sealed portions and frozen.

And thank-you again for the feedback.

JHCCoffee

LMSC The decaf requires a lower dosage than the normal - I normally dose 1-1.5g less

Thanks again for the suggestions, LMSC. I always drink decaf, so unfortunately I do not know what a normal dose is. By suggesting “dosing less”, are you recommending a higher brew ratio (lower dose, same output) or the same brew ratio? What’s your thinking behind this suggestion

LMSC

I normally dose 14g in a 15g basket or 17g in an 18g basket. Based upon your suggestion, should I try 15.5 or 16.0g in the 18.0g basket? Assuming so, what is your rationale for that? And would I maintain the same brew ratio or increase it?

LMSC

JHCCoffee The dark roasts would be fluffier. so, you may dose less. If a light or medium-light roast, I would dose 17g; otherwise not more than 16.5g. The ratio is what you like. My general preference is 1:2 or 1:2.5 — depending on the roasts. Some prefer 1:1.5 for dark roasts. Let your palate dictate your ratio.