Under or over extracted - sour or bitter??

[dmuk]

I am trying to dial in my machine but am struggling with something funamental - is the coffee over/under extracted? I cannot distinguish between bitter and sour.

The espresso charts provide a taste scale from sour (underextracted) to bitter (overextracted).

I am thinking the easiest method is to brew two cups - one finely ground, one coarsely ground - and see what tastes better?

[Blues1143]

Covid test?

[WhatEverBeansNecessary]

Personally I wouldn't worry too much about the definitions of over or under extracted.

Just change 1 thing at a time - eg grind setting, brew the same way as before (or as close as possible) and then taste it. Does it taste better or worse?
Change the grind setting again, does it taste better or worse?
Change another thing, like dose. Does it taste better or worse?

Some people really like acidic coffee. Some people really like bitter Italian style espresso. Most people somewhere in the middle with some balance. Just try work out what is good for you.
As long as you are in the ballpark of dose, yield and time - don't sweat it too much. Just change 1 thing and see if it's better or worse.

[Superman]

Bitter/sour confusion is a thing, google it. A G&T is bitter, a whisky sour is obviously sour.
I find sourness is a good way to id under extraction. However bitterness can be due to other things apart from over extraction, eg burnt milk and over roasting.

[tompoland]

dmuk Event the terms "under extracted" and "over extracted" confused me at first.

My understanding is as follows (more experienced members please feel free to correct or add/subtract/refine/mutilate as you see fit):

"Under extracted" espresso tends to flow fast, have a very pale color and is often described as "sour". A common cause of under extraction is that the grind size is too coarse so the water pressure does not build up enough to extract the flavor/color from the beans.

"Over extracted" espresso tends to flow very slow, have a very dark color and often described is as "bitter". I would describe it as intense or super strong flavor. A common cause of over extraction is grinding too fine.

[Lyrebird]

FWIW coffee is almost never bitter*. The character usually described as bitterness in coffee is astringency.

To see the difference between sourness and astringency, take a coffee, split it in half and add bicarb soda to one half and egg white to the other.

The half with the bicarb will retain astringency but lose sourness, the half with the egg white will be the opposite.






* As someone mentioned above, quinine as in a G&T is the standard for bitterness, which is a flavour: the quinine is exciting the bitterness receptors on your tongue.

Stong black lowland grown tea is an excellent standard for astringency, which is a texture: the polyphenols in the tea are binding the salivary mucoproteins why prevents the parts of your mouth sliding normally.

[Lyrebird]

Ha.

Nerd alert: The solubility of the major protein in egg white (ovalbumin) increases as you move up from the isoelectric point so adding bicarb actually makes it more soluble. If the egg is fresh the heat of the coffee will denature the ovalbumin, if the egg is from a supermarket it probably won't.

[Barry O'Speedwagon]

Best to let the coffee cool first then.

[tompoland]

Lyrebird ... that's what I meant to say ;-)

[robusto]

You've heard of Boronia Marsala Al uovo....I think the next big thing is espresso al uovo. Thanks Lyrebird.

[Lyrebird]

The Australian wine is an imitation of a Sicilian wine from the region around the city of Marsala.

The wine is "enriched" with egg yolk rather than being fined with egg white. I think this was introduced by an Englishman who popularised what had been a tiny regional specialty at the end of the 18th century.

[Budgiesmuggler]

I am trying to dial in my machine but am struggling with something funamental - is the coffee over/under extracted? I cannot distinguish between bitter and sour.

The espresso charts provide a taste scale from sour (underextracted) to bitter (overextracted).

I am thinking the easiest method is to brew two cups - one finely ground, one coarsely ground - and see what tastes better?

or buy a TDS meter and test your coffee. I bought a cheap one on alibaba that does ok.