Espresso stays underextracted

Beginner and pro baristas share tips and tricks.
Jeeheon

Postby Jeeheon » Apr 14, 2018, 3:09 pm

I'm trying to dial in Modern Times' Guardian Spirit but can't get something nice. I tried ristrettos to no avail so I set it for 22g in and 44g yield. At a grind setting I used it took about 40 seconds. Any finer a grind and nothing will come out. Yet it's still underextracted. Should I keep increasing yield? I feel like I'll have to grind coarser but then I might even end up at 3:1 before I hit over extraction!

stherric

Postby stherric » Apr 14, 2018, 3:38 pm

At a certain point, extraction will actually start to decrease the finer you grind. There is a lot to unpack here. Are you measuring extraction or tasting it? I would drop the dose, maybe grind coarser, and do a 2.5:1 and see how that works. We need more specifics about grinder, coffee, setup, etc to really diagnose this.

Jeeheon

Postby Jeeheon » Apr 14, 2018, 5:00 pm

stherric wrote:At a certain point, extraction will actually start to decrease the finer you grind.


Why does this happen?

stherric wrote:I would drop the dose, maybe grind coarser, and do a 2.5:1 and see how that works. We need more specifics about grinder, coffee, setup, etc to really diagnose this.


Yup, I found their own recipe for it online and they recommended 21g in, 52g yield in 29sec. Now it's balanced!

stherric

Postby stherric » Apr 14, 2018, 5:59 pm

Jeeheon wrote:Why does this happen?


At a certain grind size the water becomes blocked and will channel severely once it starts flowing.

Mrboots2u

Postby Mrboots2u » Apr 15, 2018, 4:18 am

The accepted way of stating a brewing Ratio is coffee to water, so try going to 1:4 if need be. Taste, adjust.

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Peppersass

Postby Peppersass » Apr 15, 2018, 5:51 pm

Just an FYI: Ristretto shots (brew ratio greater than 1:2, aka "pulling short") are likely to be under-extracted because there's less water moving through the coffee. A finer grind can compensate somewhat by exposing more surface area and slowing the flow for more contact time but, as mentioned, after a certain degree of fineness the "fines" will pack togther and block the flow enough to decrease extraction.

Ristretto shots were commonly used by third-wave cafes back in the day when espresso blends and SOs were roasted darker than they are today. Those coffees tended to over-extract and taste bitter when pulled Normale (1:2 brew ratio.) Ristrettos usually don't work very well with today's much lighter roasts, which are harder to extract. Typically the result is a sour, under-extracted shot.

The revised shot worked for you because you pulled enough water through the puck with enough contact time to get a full extraction. These days Lungo shots (brew ratio less than 1:2, aka "pulling long") can be the solution for pulling very light roasted coffees.

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