As inspired by the OE Apex thread. Just wanted to solicit HB members' opinions on the issue.

I'll share a quick Instagram exchange I had recently to kick things off:

I wrote:Anecdotally I've found that sifting fines slightly increases clarity and sweetness but at the expense of overall complexity. Also requires updosing in order to achieve good body/mouthfeel. Then factor in the average 3g fines per ~18g dose (Feldgrind 1.1, v60 prep) and you're well on your way to both a more labor intensive and expensive cup of not-necessarily-better coffee.

Scott Rao wrote: Fines are fine for espresso. They have no virtue in filter, other than perhaps contribution to body. I have zero doubt about this.

If fines were fine for filter, why would: sifting create cleaner, prettier coffee? Why would batch taste best at the coarsest settings? Virtually fines-free roller mill capsules make filter with massively high extractions and no bitterness or astringency?

[regarding sifting] You'll lose some body but you gain massive flavor clarity. As for complexity, I think that's an illusive concept that's hard to agree on or replicate

Matt Perger wrote: they're fine in terms of their extraction yield not being any different than the exterior surface of all grinds (the first thing mentioned in these comments Scott and I *actually* disagree on). In terms of flow and porosity they're annoying as hell for filter.

I don't have an answer and don't have sieves.

I do read a lot of rationalizations. Fines are great /bad they control flow / add cellulose are bitter / add body etc. maybe all or a subgroup is accurate / inaccurate / meh.

Many of the rationalizers are convinced/certain/somewhat sure / feel that it might be.

Ask sievers and the results don't seem as clearly articulated. They like it but don't feel it is worthwhile. They do it sometime. But very few seem to be pushing a sieving is better agenda. That is why I don't own sieves.

There are lots of hypothesis and very little scientific observations that prove the case one way or another.

Edit: there was at least one engineering observation in the Brita Folmer book. It seems Nestle and others are sieving (actually more like winnowing using puffs of air). If seems fines cause problems in the instant coffee processing. Maybe they clog up the filters?

If you listen to this lecture by Matt Perger, he thinks that fines are great and that boulders are the true enemy. He actually recommends sieving to remove boulders, but not fines. He also says he thinks it's very difficult to over extract coffee unless you are purposefully trying to do so, which I don't agree with. Anyhow, it's an interesting watch:

I've heard there's more that goes into this. Such as not just the fact that fines are present, but how many fines are there and what is the total grind profile (what percentage of the total grounds are fines vs desired grind size vs boulders). If you have a fairly flat grind distribution vs a single large peak vs 2 medium peaks, the taste and how the fines effect things, will be different. I've tried Kruve sieving and I don't get it. I should probably try it more but it's a waste of coffee. My problem was I couldn't get a good taste after sifting and discarding fines. Then there are coffees like Turkish that are all "fines" (compared to a filter grind) and taste good, complex, etc. Starbucks adds "micro-fines" (coffee dust) into their Via packets and I think that very much helps body and taste.

I haven't given sifting a fair shake really (no pun intended). But I don't think, with a good enough grinder, that it's necessary. Is it better? Not in an immediate way since it seems to require exploring how to get a good brew after tossing the fines.

In my oppionen they are both wright and wrong.

Fines can be both good and evil depending on their current state in either free form or sticking/clustering. If the fines is in their free form the fines don't contribute with anything desirable. In their other state the fines somewhat make the larger particles extract "better" than if you remove them from those particles.

Whether or not you like the changes "science" and more knowledge about coffee has brought with it, is obviously an Individual thing. Personally I think the coffee has improved greatly from it, we are vastly better at roasting today then we where 10 years ago, we simply have a bigger understanding of whats going on in the roasting process, improving the likelihood of a well roasted coffee

Drink what tastes good to you.

Taste is all thats important. Not TDS, not extraction %, not what someone else thinks coffee should be.

Fines are a part of handmade coffee. I can tell fines from the bloom, its a puffier bloom with more fines. It also tastes better imo. But this may depend on overall recipe followed, and taste profile you want.

This is also purely anecdotal, but first, the question of what fines do has already been answered, right? We know that the size of the coffee particle is mostly responsible for the taste, or profile, of the coffee. Grinder is the most important. You grind down to an espresso consistency, it tastes different from French Press.

So fines are just a slightly different tasting particle than whatever you're grinding. Removing fines would predictably take out that taste, and the body they contribute, which would be perceived as clarity, at the expense of overall complexity, or different tastes, as you said.

I don't think it needs to be any more complicated than that.