Ok to use smaller doses in a big basket? - Page 2

#11: Post by **Nate42** » July 26th, 2014, 8:52 am

endlesscycles wrote:Probably not. Getting good extraction is already near impossible with espresso. Low resistance baskets and a finer grind is a good idea in my book.

Yeah, but this is talking about 12 grams in a 22 g VST. Surely there such a thing as too much of a good thing? Im not a refractometer kind of guy, and maybe the terminology isn't 100% correct, but if I'm cranking my grind down finer and finer and reach the point where it stops tasting good, I call that over extracted.

July 26th, 2014, 9:02 am

If it's bitter, and it's not the bean, 99% probability that it's over-extracted. The most likely causes of over-extraction are too fine grind, too low dose, and/or too hot water.

Over-extraction and "good extraction" are largely different. Over-extraction is a question of what's in the solution, not how much; and has little to do with yield.

Rich

#13: Post by **boar_d_laze** » July 26th, 2014, 9:22 am

OldmatefromOZ wrote:I guess a lot depends on the roast to? lighter roasts will do better.

Seems right.

A lot of people generalize about light vs dark in terms of how they're going to grind and dose, and how they're going to temp, and maybe that gives them a leg up when it comes to dialing in. I just figure every coffee is sui generis and start the dialing in process from scratch whenever switching to something new.

Rich

#14: Post by **MWJB** » July 26th, 2014, 9:57 am

boar_d_laze wrote:Over-extraction is a question of what's in the solution, not how much; and has little to do with yield.

Rich

Overextraction is precisely a case of having too much in the solution (for a given dose). There are usually peaks & troughs of good flavour vs extraction yield, you may have a higher extraction than another that doesn't taste as good, but it's only overextracted if pulling more out of the coffee can't help. If you have a factor that prevents you from overextracting, which can happen, then this may seem like a distinction without a difference.

#15: Post by **boar_d_laze** » July 26th, 2014, 10:19 am

MWJB wrote:Overextraction is precisely a case of having too much in the solution (for a given dose).

I'm not sure if you're using the term "given dose" as a sort of savings clause. Perhaps we're actually saying the same thing.

I apologize for misusing the term "yield," when I meant "strength" (concentration), which undoubtedly was confusing. Over extraction is very much related to yield. Over-extraction is a product of yield, not concentration. Yield = Percentage by weight of coffee dissolved.

From Wiki:

Yields of over 22% are "over-extracted", specifically bitter, as bitter components continue to be extracted after acids and sugars have largely completed extraction.

In other words, over-extraction is a product of what's in solution (those bitter components), not how much.

Rich

#16: Post by **MWJB** » July 26th, 2014, 10:40 am

boar_d_laze wrote:Horsefeathers! Weak coffee can be over extracted and bitter.

Rich

Indeed it can, as can strong coffee be sour & underextracted...both weak & strong coffee can also be nominally extracted. Weak & strong (concentration) are largely independent of extraction yield. Concentration is the amount of coffee dissolved into solution, relative to the weight of the solution - on it's own, this tells you nothing about extraction yield. Extraction yield is the amount of coffee dissolved, relative to dry dose - this is the parameter by which under/overextraction is assessed.

Otherwise all drip brewed coffee (~1.15%TDS to say 2.00%TDS) would inherently be prone to one defect & espresso (~5%TDS to 15%TDS for example) the other.

This video explains the relationship well...
http://vimeo.com/67386871

#17: Post by **cpreston** » July 26th, 2014, 9:15 pm

I believe the problem with very low doses in oversize baskets is partly poor filtration performance, leading to excess particulates in the cup.