A scientific run-down of coffee blooming | Hacker News Reader

A scientific run-down of coffee blooming

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84 pointsgreen-eclipse56 comments

I went through my coffee hipster phase. But I eventually came to the conclusion that my palate is just too unsophisticated to tell the difference between supposed “hints of blueberry and molasses” in third wave hipster coffee from a boutique roaster versus the cheap coffee that my local newsstand brews every morning.

Now my only concession to coffee is brewing a cup on a Technivorm. Also Hawaiian coffee is super smooth and mellow which I like, but serious coffee aficionados apparently don’t like it for the same reason.

I'm still in that phase, but I like my coffee to taste like coffee. Not necessarily one-note, but not akin to fruity tea (as can be the case brewed with blonde roast, coarse grind, lower water temp, fast percolation). I stick with medium to full-city/espresso roast. Though some single-origin differences can cut through, they don't make much of a difference to me. Where I am enjoying variety more is in my brewing process, french press vs hario switch vs moka pot.

Everyone's coffee journey is unique and that is awesome!

The palate is a bit like a muscle. Some people have bigger/better ones naturally, but everyone can improve what they have with training.

There's also value in having a mediocre cup of coffee on the regular. A little saline solution goes a long way in improving palatability.

I learned enough to know what I like, what I don’t like, and what doesn’t matter to me.

I don’t like expensive coffee that use “fruit” descriptions to their flavors. I like the expensive ones that use “chocolate” or “nuts” descriptions.

I like anything from 1:12 to 1:16 ratio (in my routine, 9g to 12g of coffee to 150ml of water).

Grain should be fine, but I don’t need a precision grinder.

Precise water temperature doesn’t matter much.

I like pour over. Not so much french press, aeropress, espresso, or moka pot. I still drink it, just prefer pour over.

Regular filter coffee at a café, cheapest store-bought Segafredo powder in a moka pot—I still like that more than almost any expensive coffee (as far as black coffee goes, at least), but there is perhaps one particular hand drip the taste of which beats everything. It’s hard to come by and I do not know how to describe it except that it is not sour at all and is diametrically opposite to what many coffee hipsters want (“what is your sourest bean?” is something I overheard once or twice).

I got the beans, same beans roasted and ground in the same way in the same shop where I found my desired taste recently, and after making it a couple of times learned that too many things affect the taste. The first time it was good, the second time it was too sour. It is “fun” trying to diff the culprit: water temperature? way of pouring water? psychosomatic factors?

A fun fact I re-learned recently and was able to replicate for myself for coffee: there are different sensors in different parts of your tongue that taste different aspects; sides taste sour more so even the shape of your cup affects the result (wider cup may taste more sour with the same coffee).

The tongue map is debunked: https://www.smithsonianmag.com/science-nature/neat-and-tidy-...

I wrote that I have personally observed it. One cannot debunk a factual data point.

Even if one could, the article you linked does not even attempt to do that:

> Hänig found that there was some variation around the tongue in how much stimulus it took for a taste to register. <…> Hänig’s hypothesis generally holds up. Different parts of the tongue do have a lower threshold for perceiving certain tastes, but these differences are rather minute.

Within the category of “coffee”, all differences are minute. The whole point of coffee hipstertude is enhancing individual sensitivity to those minute differences in taste in order to pointlessly argue and express sophisticated preferences about such.

(It took me years of drinking single origin hand drip to just start noticing a difference between light and dark roast, and believe it or not there are people who have much more narrowly defined tastes.)

Diner coffee is something I appreciate as a separate category, you can consume several refills of without feeling it much. I don't love it like e.g. local medium roasted coffee, but it's pleasant.

Me too. I went from using various pieces of equipment and freshly grinding it every day to simple cafetiere coffee using pre-ground coffee.

Then I got into coffee again and wondered what the hell was wrong with me. Life is too short for bad coffee. If something is forcing me to make such sacrifices in things like coffee and food I fix the thing.

> Life is too short for bad coffee.

Amen.

Some would argue you adjust your "baseline" overall satisfaction by going without x/y/z regularly, but why race to the bottom into asceticism with that idea? It's basically the most pleasant thing I consume all day, as I do away with junk foods.

Same here. I tried coffee subscriptions to see if I was missing something by trying different roasters. Nope, it just tasted like coffee. I've tried Aeropresses and other doo-dads, and still, coffee tastes like coffee.

I will say that I just bought a used Bonavita BV1800TH for $9 from a Goodwill store, and all the sudden my 3lb $17 bag of Costco ground coffee tastes significantly better in the Bonavita. Although I'd love a Technivorm one day.

I might have to revisit some different beans again, now that I have a decent machine.

I’ve long assumed that the main effect of the bloom is to soak the grounds so the rest of the water you pour in goes through slower, and all the other alleged effects were minor compared to that.

But maybe the CO2 removal stuff really is a big deal.

TFA seems to agree with you; it says that bubbles are an indication that the coffee was unevenly wetted.

I’ve taken to stirring my coffee as I pour the hot water in. Definitely seems to ensure that all the coffee grounds ate wetted.

> But maybe the CO2 removal stuff really is a big deal.

It’s definitely a thing. There are some super light roasts that if you try to brew them without enough resting time, you can sort of cheat by just grinding the coffee about 30mins before you brew for a hacky quick degas. It really helps get rid of that grassy vegetal taste.

There should be no grassy taste, that’s a roast defect and comes from inconsistent roasting. You should find a better roaster. You can roast really light and not get that taste, but you need to be consistent.

Maybe grassy wasn’t the right term. I don’t mean under developed, it’s kinda bitter and sharp without any sweetness. I’ve experienced this with pretty legit roasters like apollons gold. It seems like the lighter the roast, the more time it needs to degas before it hits the sweet spot.

I've found that lighter roasts don't degas/bloom anywhere near as much as coffees that are taken even a little more darker (like talking about the difference between super light and light). I think this continues up to second crack. I'd guess that the breaking down of the cell walls in the bean has something to do with it, more roast more breakdown = more C02. I actually think the C02 is just probably not even created in lighter roasts.

There was a post here a few months ago saying that blooming prevented static electricity build up within the coffee grounds which made them clump together (or something like that anyway), I thought it was interesting.

That’s not the bloom phase, that’s misting the beans before grinding.

In my own attempt to bloom coffee in an Aeropress, the result is, strangely, that it takes much longer to extract the coffee to 'full strength' if I bloom it, compared to not blooming it. If I bloom the coffee, then fill up with water and stir, the result is under-extracted unless I brew for longer. If I just fill up the water immediately and then stir, it takes much less long to brew to the same 'strength'. This is the opposite of what should be happening. But I am using light-to-medium roasted coffee, and this article notes that bloom and roast are interconnected, so perhaps this is normal? All I know is, coffee brewing seems to be much more an art than a science, regardless of how much you try to focus on the science. Dial it in to what tastes good to you, and that's all that matters.

Blooming in an Aeropress would seem to be unneeded to me if you are agitating.

Any type of immersion brew benefits from immediate agitation in my experience, aeropress and french press (which gets aggressively swirled under my hot water tank while it's filling.) You can aggressively stir aeropress as well, you just need to manage it dripping from the bottom using more filters, finer grind, invert method, etc.

Aeropress should make this acessory standard-issue with their coffee makers, so that we don’t have to rely on other methods to reduce drip-through:

https://aeropress.com/products/aeropress-flow-control-filter...

The inverted method is an even easier way to achieve this :)

You still have to screw a lid on it, how is it any easier than simply screwing on a different lid? Or perhaps you meant “cheaper” instead of “easier”. :-)

Perhaps you're letting your water cool? If the water in the kettle cools, and the water in the grounds cools while you let it bloom, then when you combine them they'll have a lower strike temperature then if you were to introduce the water all at once.

Could this be a result of low-strength brew draining through during the bloom, which then has to be compensated for with a stronger brew for the rest of the cup? Or is the bloom being done upside down?

I mean 90% of coffee brewing is meaningless rituals. Could you taste the difference between a burr grinder and a blade grinder in the resulting brew? Nope, but endless pages of debate exist on this, grain size distribution, quality of burrs. It has a strong resemblance to the audiophile community.

Of course you can detect the difference between a blade and a burr grinder: how much sludge is at the bottom of your cup?

That said, is it really meaningless if it gives you personal satisfaction and peace? Is it any different than any other routine or ritual, like going to church on Sunday?

>> burr grinder and a blade grinder

Come on over and we can do just this in my half assed home espresso machine.

There will be a difference.

The process, roast and general quality of coffee matter.

Can one make magical claims about all of this. They sure do and charge an arm and a leg for it. But you can get a quality product an a consistent cup at a reasonable price if you shop around.

On blind color difference tests, I score 100% when your average person scores less than 60%.

I laugh when people say two colors are the same.

Huge difference between burr and blade.

I mean this is pretty easy to test without making unsubstantiated claims. I’ve done this. We have a range of grinders from $700 to $5000 and did an informal blind tasting. No one had tasted coffee from all grinders.

Guesses were revealed simultaneously. 100 percent hit rate.

Are you using the same amount of water in both cases? I sometimes overdilute the coffee because letting it bloom lets the current water drain away.

I learned that I like without bloom phase. The CO2 getting in the way of extracting flavor might be a good thing, since (at least that is my understanding) the more acidity flavors are extracted later. I like the coffee with more sweetness and less acidity, so I just skip the bloom phase, pouring all at once, it extracts less of the coffee, only the good (for me) parts.

Gentle circular pouring can prevent dry coffee blocks and the creation of channels. I also do a little swirl with the filter to flatten the coffee bed. So it is possible to avoid those issues even without the bloom phase.

It works for me, even though I am not a hundred percent sure that I got the science of it right.

At least, some coffee specialists support my choice:

https://youtu.be/miuPSjazpyw?si=_UPZfh9O0YYZwmri

Sounds like your grind might be too fine tbh

Idk. I have a cheap grinder that grinds unevenly, so at least it is not uniformly too fine.

The barista in the video does use fine grind for this no bloom method, though, so it makes sense. I like the result of the no bloom with my grinder though, so I am happy with it

If you’re happy with your coffee then that’s what matters in the end.

I’d recommend trying a burr grinder though, or getting your coffee pre ground with one, it makes a significant difference in my experience.

> the more acidity flavors are extracted later

The first compounds to be extracted with coffee tend to taste sharply sour, shifting to sweet and then to bitter as the brew progresses - you can actually taste this directly by sampling a bit of the coffee that drips out at the start, middle, and end phases of your brew.

I found this guide to be helpful when I was first getting started: https://www.homegrounds.co/wp-content/uploads/2021/10/Coffee...

So the way I do seems to stop before the bitter notes.

Thanks for the correction. Nice chart too

One coffee phenomenon I'm curious about: why does old coffee get cloudy?

On the day I brew it, it's a dark brown translucent.

But if I leave it in the pot overnight, it's definitely more opaque.

My wife claims it tastes the same as the day before.

I assume it's just the emulsion breaking.

fresh coffee has a distinct taste. Maybe your wife is just used to day old coffee lol

> fresh coffee has a distinct taste. Maybe your wife is just used to day old coffee lol

I can definitely taste the difference, and I much prefer fresh coffee.

She just can't taste the difference for some reason. Which surprises me, because AFAIK her sense of taste is otherwise normal.

One difference might be that I strongly notice "bitter" and find it unpleasant. Maybe bitterness is one of the key differences in stale coffee?

It mentions immersion methods and then never revisits it :(

I used to use a Chemex but found the whole process so fickle and involved. I've since switched to a Clever dripper (similar to the hario switch) and found that my coffee life has improved substantially. The basic idea is to let the coffee sit with the water for a bit and then flip a switch to drain it into your coffee. I prefer the consistency of the method and haven't noticed a difference in flavor.

My latest project has been attempting to speed up the cold brew process (to get low acidity cold coffee for the summer) and I've taken to using a sous-vide. The idea is that low heat will reduce the time needed for extraction without actually causing the water to leech acidity from the beans. It's worked, but results were kinda meh. I just bought some PH strips to run a more thorough experiment, though.

I really enjoy the Clever dripper too. My big revelation (from a James Hoffman youtube video) was that putting the water in first, made the whole process so much faster and maybe even tastier.

I'm curious to how this applies to the Aeropress because in that system, you actively stir the coffee for several seconds.

> 30 grams of coffee, 500 grams water at 205°F

Woah, that's too hot IMO, and a bit watered-down.

Me: 33g coffee, 350g water at 190°F

16:1 water:coffee ratio is a pretty common starting point. Your brew is pretty intense!

I’ve found that darker roasts are much nicer around 195F, I mainly brew very light roast and almost all of them come out under extracted at temps below 200F

Ok, I've been doing 190F for a while so I need to given high temp a try again, thanks for helping me continue exploration

Good luck! Remember that the only real acceptance criteria in coffee brewing is “do I like it?” =)

Obviously immersion brewing is different than percolation, but the 16g water : 1g coffee ratio is exactly what James Hoffman recommends in his "Ultimate French Press Technique": https://www.youtube.com/watch?v=st571DYYTR8

For OP's light medium roast (dark roast prefers cooler temps) Hoffman says high temps aren't a problem and shows hard boiling water lead to peak brewing temperatures of 90-93C: https://www.youtube.com/watch?v=K_r5kpXPRYo Other youtubers have done blind taste tests and found they liked boiling water brews best with light roast coffee.

Not saying your taste is wrong either, just that OP is doing things a way described as ideal by at least one coffee expert! Lots of ways to brew.

For dark roast yes, but for lighter roasts they are usually more dense and you could get a sour bree

206F/95C is the recommended temperature, some brew fine at 100C.

Obligatory James Hoffman link: https://www.youtube.com/watch?v=K_r5kpXPRYo

Hot water is fine.

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