Burnt Espresso Taste Solutions?

JHCCoffee

Hi All

I purchased some decaf Brazil Bourbon Santos and Sumatra Mandheling from a roaster that I had not tried before, which I blended 50/50. I have poured 5 shots thus far, which I have been drinking as cappuccino. The coffee has a burnt taste.

The roast is apparently City+, at my request. However the oils that show on the surface of the beans (and the width of the bean crack) make me think that they might be Full City or even Full City+. The beans are 2 weeks off roast.

I have been using a 14 in, 26.0 to 26.5 to 27.0, out (1:1.85 to 1:1.92 ratio) in a 15g IMS basket.

I tried: a) reducing the temperature from 95C to 94C. b) grinding 0.5 coarser on my Niche. As a result the coffee tastes not as heavily burnt as initially, but still has unpleasant burnt flavours. And it seems to lack other coffee flavours and strength. I could go to 93C and even coarser but suspect that the result will not be great.

I am about to throw out the coffee. Well, I might wait, and try the Ethiopia Natural Sidamo and Brazil Bourbon Santos decaf blend that I also bought from that roaster and see if that also tastes burnt. I also have one of their proprietary blends to try. Hopefully they have not over roasted all 😡

I find that it is challenging to find roasters that know how to roast decaf. I have found afew but have rejected many.

Rob1

You could try decreasing the yield.

JHCCoffee

Rob1 You could try decreasing the yield.

Interesting idea. I’ll also give that a try.

Fyi, I read a Jim Schulman post at HB that recommends pulling more ristretto shots for decaf. Others on that thread complain about “sharpness” in their decaf.

I’m betting though that if I both drop the temperature (as well suggested by LMSC ) and drop the yield (say 1:1.75 vs my current 1.85 to 1.90) then I will lose ALOT of extraction.

LMSC

The temp is too high, IMO. Please drop it to 89/90 and see if it helps.

Given the process the beans go thru’, the bean structure of a decaf is fragile than the standard coffee. The cell walls in the decaf coffee tend to rupture at a lower temperature, allowing oils to pop up to the surface, although it may not have seen the second crack. You might see the oil a few days after it has been roasted. The decaf beans tend to be darker than standard beans.

JHCCoffee

LMSC The temp is too high, IMO. Please drop it to 89/90 and see if it helps

Thanks LMSC. Will try that.

When I do that, I suspect that extraction will substantially decrease. How should I compensate for that? I can try increasing the OPV pressure …

Also curious. I’ve been pouring my other decafs at 95c without these burnt tastes. I pour a decaf Hawaiian/Columbia blend that is roasted to City roast, at 94 and even 95C without burnt flavors. With that Hawaiian/Columbian blend, I had started at 93C and found that higher temps (94 and 95C) increased extraction (though I should haul out my refractometer to confirm that). Might there be something about the sumatra/brazil blend that causes it to taste burnt at 94/95C?

A related thought. All of my decaf espresso shots just do not taste sweet, such that I don’t enjoy a straight espresso shot. Great in milk, but not straight unless I add sugar. I’d love to find a solution to that.

Anyway I do appreciate the suggestion re the Sumatra and will definitely try dropping the temp to 90C.

LMSC

JHCCoffee I would go by taste. Try pulling 1:1.5. You can also go finer and see it it helps. I have never pulled a decaf at those temperatures on my lever.

IMO, the Brazilians are less soluble than Sumatrans. The latter allows you to grind coarser, while the former requiring finer grind. Not sure, how this blend would work. :-)

LMSC

JHCCoffee One at a time!

Rob1

Decreasing extraction is probably what you want. High EY isn’t always better. How strong this burnt/roasty taste is would determine how much of a change to make to correct it. It could also just need a longer rest.

JHCCoffee

Rob1

Good point on the EY.

I also went for a somewhat shorter (2 week) rest with these beans (in fact with my entire order from Dark City) as I needed I change from my go to beans. I had also begun to notice that 4 weeks rest was perhaps beyond peak flavour in my Hawaiian/Columbian decaf beans. Perhaps I should have waited a further week. Just curious. How would a shorter vs longer rest impact these burnt flavour notes?

Rob1

A longer rest lets roasty flavours ‘offgas’. Brazils and Sumatra can be ashy and burned quite easily, probably doubly so for decaf.

JHCCoffee

Rob1 Brazils and Sumatra can be ashy and burned quite easily, probably doubly so for decaf.

Hmmm …. I was looking to blend the Sumatra with something, in order to smooth out its intensity. Should I have used a Columbian instead?

JHCCoffee

Rob1 A longer rest lets roasty flavours ‘offgas’. Brazils and Sumatra can be ashy and burned quite easily, probably doubly so for decaf.

So if I understand this right, if the roaster is not highly experienced and skilled at roasting decaf (which is not easy), then (especially with Brazils and Sumatras) they can cause burnt flavours which then have to be solved through: a) longer rest periods, b) lower water temperatures c) shorter brew ratios, with b) and c) resulting in less extraction.

Fyi, I this morning encountered similar burnt flavour issues with an Ethiopian/Brazil decaf blend from the same roaster. I suspect it was/is the Brazil that is burnt, as this Brazil was also in the Sumatra/Brazil blend. I was able to eliminate the burnt flavour by reducing the temperature to 91C and shortening the brew ratio just slightly, to 1.85 (14 in, 25.8 out). Body is ok, but strength and flavour is still insufficient. So I suspect that while we got rid of the burnt tastes, we also (by reducing extraction) also substantially reduced the other flavors that we wanted. Will try a slightly longer shot at 91C to see if I can get some flavour back.

JHCCoffee

Thanks for the suggestions, guys.

For the decaf Ethiopian Sidamo, the key item was dialing back the temperature to 91C, which eliminated the burnt taste. Making the grind coarser allowed a faster flow eliminated the last vestiges of the burnt tastes, but also extracted some of the better flavours. Just need to reduce some astringency. Took 7 shots, but we’re almost there.

Will tomorrow try the above approach with the decaf Sumatra.

mobius

JHCCoffee Just need to reduce some astringency

Curious how you would define astringency - I’ve seen it mentioned in a few places, but never sure how it manifests. Fascinating to read along with this, and apply to my own process.

JHCCoffee

mobius Curious how you would define astringency

The closest taste parallel I can think of is the tannic taste of a red wine that has alot of tannins (tannin acid) and is young (the tannins have not resolved). A “drying” sensation. But not as extreme as a tannic wine.

Is astringency the same as an acidic taste? Not quite, IMHO. An acidic taste is more pickling. Its the acidic taste of a lemon or a lime or bottled orange juice.

The astringent taste I refer to is a mild combination of dryness and acidity. Its a sign of over extraction.