In the last few months, I've cupped about 20 different natural and anaerobic coffees from various sources and roasters, including my own home roasting efforts. I've also talked to several people about my experience.

Turns out, everyone is OK with naturals or anaerobics that have no ferment notes at all; where the dry processing just adds a little sweetness, but doesn't add any strange flavors, that is, flavors that do not originate in the coffee cherry. Some people, call them the coffee purists, are not OK with any ferment notes at all. If it isn't in the coffee cherry; it shouldn't be in the coffee after it is processed. Even if those flavors are pleasing, like the blueberry notes in some Ethiopian coffees; they aren't coffee, just flavorings added after the cherry was picked.

I'm not a purist, nor are lots of other coffee lovers. For us, a natural that has added ferment notes can be either good or bad, depending on the ferment notes. But "I like good ferment and not bad ferment" is an empty tautology, basically "I like what I like;" it is not a way to judge anything.

So I'm proposing a very simple test for judging ferment flavors, the wine to sauerkraut ratio. are the acidity and the acid carried flavors mostly acetic and vegetal, i.e. sauerkraut; or are they mostly tartaric and fruity, i.e. winey? Treat sauerkraut flavors as a taint that ruins the coffee; treat winey flavors as a bonus created by your friendly yeasts from the sugars and acids in the coffee cherry, like wine from grapes.

Looking back at the notes on all the coffees I tasted during my anaerobic journey, the wine to sauerkraut ratio was the best predictor of whether I liked them or not.

So what does everyone think?

Had some recent anaerobic coffee that I would describe as having a touch of sweaty socks, where does that fit into your scale?

civ wrote: {about coffee purists believing pleasing ferment flavors are added, nit real coffee} Not a purist.
But that's what I think.

Didn't think anyone would say "it's not really coffee; but I'm OK with it" for the fruity-winey ferment.

John49 wrote:Had some recent anaerobic coffee that I would describe as having a touch of sweaty socks, where does that fit into your scale?

As far as I know, that may be a plain old mold taint that used to be quite common in African and Indo coffees. "Baggy" and "horse blanket" are similar names for this kind of taste effect. Ferment flavors, on the other hand, tend to be associated with acids.

A lot of the aerobics I tried also had woody notes, like green coffees stored in bourbon or beer barrels. I'm not sure what this is due to; but maybe when it goes wrong, it smells like old socks

another_jim wrote:As far as I know, that may be a plain old mold taint that used to be quite common in African and Indo coffees. "Baggy" and "horse blanket" are similar names for this kind of taste effect. Ferment flavors, on the other hand, tend to be associated with acids.

A lot of the aerobics I tried also had woody notes, like green coffees stored in bourbon or beer barrels. I'm not sure what this is due to; but maybe when it goes wrong, it smells like old socks

Two coffees from the same grower, a bourbon and a geisha had this funky taste, possibly a feature and not a bug.