I think this is an important insight. Some people don’t have much experience in making repeatable coffee, and whether you make the coffee well is more important than how good the grinder is.

But once you have repeatable steps and that are good (water, quantities, temperature etc.) the grinder becomes the most important piece even in espresso.

Not really, almost everything else matters more. Bean quality and water quality in particular are at the top of the list. Good beans bad grinder > bad beans good grinder. The grinder is the last place to look, even though it does matter.

The mistake you’re making is that not all variables are under your control.

Getting better and better beans is very hard. You’re stuck with what is available. You’re stuck with what water is available (if you’re a reasonable person). You’re stuck with the local roasters.

So of the variables you can control, the grinder is the most important piece of equipment you can buy.

Of course they are, don’t be so helpless. Getting good beans vs Starbucks is trivial. You’re obviously not limited to local roasters, google “specialty coffee delivery”, it needs to rest for around a week anyway. As is getting filtered water (in-line under your sink for less than $100, filter pitcher for a fraction of that) and saline drops (you can buy them for next to nothing online or mad-science your own for even less). All of those things will make a huge improvement compared with a better grinder.

Again. Grinders can make a difference, but they’re the last step in the chain. Do everything else first.

The other mistake you’re making is thinking people haven’t tried all of this and this is new information to them. And that trying all that results in a product that someone else prefers.

The fact is, there is a certain level of spend needed. If you’re not making espresso, this is very low these days. You can get very cheap, good gear. If you are making espresso, you’re spending several hundred minimum. Although you can lower your spend quite a bit if you’re willing to hand grind for espresso.

If you’d tried it we wouldn’t be having this conversation. It’s ok, no need to be defensive.

I would say it's most important for espresso, at least in espresso machines that do everything else well. You essentially control the duration of the pull via the grind, and the taste of the shot comes predominantly from how long and hot you pull it.

As you said, once you are dialed in, really the only variable I am tweaking per bag of beans is the grind.

It's not an important insight at all - it's a credentials fallacy. "I was in industry so I am right". Many people have spent many years nerding out on coffee, myself included, but you'll note I don't use that as an argument for being correct.

You should really reread my comment, that’s not what I’m talking about.

It’s exactly what you’re talking about. The claim was “i was in industry -> therefore i know if you control the other variables you can tell the difference”.

For one, controlling the other variables is an obvious step you need to take when testing the effect of particle size. For two, it doesn’t follow that the OP is magically correct in his hypothesis about the affect of grind size just because he thought of this step and works in industry.

Your posts are very curious. Why do you think that the credential (10 years in the specialty coffee industry) mentioned is fallacious or somehow irrelevant? It seems to me that a decade spent finding ways to control variables and improve the quality and repeatability (both in a cafe setting and for customers with home setups) of coffee is like.. super relevant here.

Also - is controlling the other variables actually obvious to most as you say? Are those variables even easily identified by the average home coffee maker? I'm not so sure.

Look I hope I’m not insulting your profession but controlling the 5 or so variables that go into brewing good coffee is not exactly rocket science. To claim to be an expert in it is akin to claiming you are an expert in sharpening knives or picking a lock. It’s something basically anybody can take up, the rules for success follow a general formula, and if you experiment just outside of this formula you’ll find the way that works best for you. Hell, even the prices of growing, preparing (fermentation), and roasting coffee beans is infinitely more complex than the brewing process imo.

So no, the fact that you claim to have spent a decade professionally controlling the water temperature, bean roast,ratio, brew time & process, and grind level, does not make you any more knowledgable than any one of the other million nerds (including myself) who do this on a daily basis as well. Yes, controlling all of the variables when taste testing is obvious to most coffee geeks (people responding here). Americas test kitchen has been doing this for decades with recipes that have many more variables than the coffee brewing process.

No, those variables are probably not easily identified by the average home coffee maker. That’s because the average coffee maker is a boomer with a keurig. I still don’t think it was a particularly insightful comment though, regardless of this fact. This forum is not made of keurig drinking boomers.

So in your home coffee nerd experience coffee made from grounds with a narrow size distribution is not noticeably different than coffee made from grounds with a broad size distribution?

No, in my home coffee nerd experience the realized size distribution across multiple grinders is minimal enough that it has no effect on flavor profile. When all other variables are controlled, of course ;).

If you like it, that's all that counts!

Exactly! Just like how all of the “experts” liked blade-ground coffee when it was blindly tested (https://youtu.be/O7LAzSKgeoQ?feature=shared), in what seems to be the only blind test that brings together experts on the internet. They liked it, so that’s what counts.

It’s easy to like something though when that something’s “taste” (when drilled down into the realm of unrealities) is largely social. That’s why John Manzo noted as such in coffee, connoisseurship, and an ethnomethodologically-informed sociology of taste.

https://philpapers.org/rec/MANCCA-3