Balance in Espresso is Intense Bitter and Sour Cancelling Each Other Out

Beginner and pro baristas share tips and tricks for making espresso.
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#1: Post by another_jim »

HB Post Balance In Espresso

How is it the same coffee, pulled wrong as espresso is a sinkshot; and pulled right tastes beautiful? A sinkshot mean we are running to the sink to spit out something overwhelmingly bitter or sour. But since espresso is ten times as concentrated as brewed coffee, why isn't every shot a sinkshot, overwhelmingly bitter or sour or both?

It turns out that Overwhelming Bitter + Overwhelming Sour = Mild and Balanced.

This is something you can confirm for yourself by doing the following experiment.

1. Mix an overwhelmingly sour mix of 1.5 grams citric acid per 100 grams water.
2. Mix an overwhelmingly bitter mix of 1.5 grams 50% Gentian root extract in alcohol to 100 grams water
3. Have some sugar syrup handy

How much sugar does it take to make the acid pleasant?
How much sugar does it take to make the bitter pleasant.

4. Now mix the bitter and sour so they taste balanced and bland

How much sugar does it take to make the mixture taste pleasant?

I tried this experiment with a class of people attending my lecture on home espresso. It turns out that 70% of the people liked a mix of between 1:2 to 2:1 of bitter to sour, while 30% were outliers. 80% of the people where happy using about 1/4 to 1/2 the level of sugar syrup to the overall level of their favorite mixture. I did not ask them to sweeten the unmixed liquids; but my personal results were about 1 spoon syrup per 1 spoon straight sour or bitter, and my other results were exactly average for the room.

The point is that all espresso shots are overwhelmingly bitter or sour. But when they balance, the bitter and sour tastes cancel each other out, and create a sort of generic soft drink flavor.

This is also a good exercise for distinguishing "bright bitter" flavors from sour flavors; something that can be tricky at espresso volume levels
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#2: Post by Martin »

I'm not clear about all that you might have in mind when you say "pulled wrong" or "right." Don't many coffees have the potential for wrong/right shots that cover the sour/bitter range? And why "intense"? Is it possible to have what we might agree is balanced/mild without what seems (too literally?) a balance of what is otherwise too much sour or bitter?

Do you have any observations about the participants" prior coffee experience and how that might affect their judgements of what is desirable or out of balance? For example, a simple personal observation is that I enjoy a component of blends that adds a touch of lemon drop, having learned to find the sweetness hiding behind the sour.

Anyway, interesting hypothesis here, and worth repeating with lots more data.
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#3: Post by kwantfm »

Thanks... nice to read a post the content of which I have never, ever considered before.
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#4: Post by another_jim (original poster) »

Martin wrote: I enjoy a component of blends that adds a touch of lemon drop, having learned to find the sweetness hiding behind the sour.
Do you enjoy sour as strong as unsweetened straight lemon juice? Or a bitter as potent as straight quinine? That is the levels you find when espresso is pulled wrong (I know it's been a while).

The point is that these flavors do not go away when you pull a shot right. Espresso is ten times as strong as a regular coffee however it is pulled, and all the extracts, bitter and sour are always there. It is that the intense flavors cancel each other out, and become enjoyable.
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#5: Post by Marcelnl »

Great find, it's much the same in cooking where usually a balance needs to be found between sweet and sour and or bitter. I never thought about espresso in this context but the underlying principle sounds to be the same.
I usually take my double espresso's without sugar although it sometimes seems to tie in the tastes and it does something with the mouthfeel but I'm not clear how that works.
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#6: Post by cannonfodder »

That is also why I stir my espresso's. The extraction tends to layer with the sweat and bitter in different substrates of the cup. A quick stir with a demi spoon blends them together giving me a more balanced drink. Those stages of the extraction can be observed with the Schectermatic cupping device. Talk about pulling one out of the way back machine, dont remember the last time I pulled out the Schectermatic.
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#7: Post by SJM »

Okay, I had to Google Schectermatic, and it really is worth sharing for anyone else who missed it :D :D :D
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#8: Post by SlowRain »

Isn't that why there was the experiment a few years ago to skim off all or part of the crema? The crema was found to be the most bitter part of the espresso. Skimming the crema altered the balance of bitter-to-sour. It's probably still a good tip when visiting a less-than-stellar cafe.

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#9: Post by Mach »

Very interesting. Brought to mind the recent interest in espresso and tonic. Tonic balances in a similar way, though usually with more (and mostly too much) sweetness. I just bought a tonic syrup with the intention of playing with it in coffee. Then I read about cinchonism (caused by a buildup of quinine in the body) and decided to wait until gin and tonic season is over. I am nothing if not cautious.

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#10: Post by Martin »

A few questions (or maybe one question asked in several ways):
1. Please say more about how you might distinguish (or overlap) the meanings of "cancel" and "balance." Or is this pretty much of a semantic fussiness that's not relevant to this post?
2. How is the taste cancellation phenomenon similar to or different from noise cancellation----as when sound waves align to actually extinguish the physics of noise from a particular source or sources?
3. Similarly, is there an analogy to mixing two colors to produce a third? In this case (say, red + yellow = orange) we might conventionally say that the original colors are blended, but not that they are cancelled.
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