# Letting coffee "bloom" **URL:** \ **Category:** Cafe Society\ **Tags:** coffee\ **Created:** [July 26, 2019, 8:03pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685 "2019-07-26T20:03:48Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![wclark\_xoom](https://avatars.discourse-cdn.com/v4/letter/w/d9b06d/32.png) [@wclark\_xoom](https://boards.straightdope.com/u/wclark_xoom)\ **Post date:** [July 26, 2019, 8:03pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/1 "2019-07-26T20:03:48Z")
We grind our own beans for our morning coffee, and recently started using a pour-over device rather than a regular electric coffee pot. My wife insists that we have to pour in just a small amount of water first, to let the coffee “bloom” before filling the container all the way. I insist this is nonsense, but I would also be fine drinking day-old coffee pot coffee reheated in the microwave, so clearly I’m not the connoisseur here. Looking online, this “blooming” nonsense is common advice, typically justified in terms of releasing excess carbon dioxide so that it doesn’t affect the flavor. But: There really isn’t terribly much carbon dioxide in the air, there isn’t all that much trapped air in with the ground beans anyway, and good luck if you’re trying to get carbon dioxide to dissolve readily into near-boiling water. I just don’t see how this could make any discernible difference. Am I wrong here? Could some experienced barista and/or organic chemist here enlighten me? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 26, 2019, 8:06pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/2 "2019-07-26T20:06:27Z")
Let’s move this to the Coffee Shop. Colibri General Questions Moderator ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [July 26, 2019, 8:34pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/3 "2019-07-26T20:34:31Z")
My skeptical suspicion is that it’s just another one of those bits of esoterica that snob hobbyists use to try and separate themselves from the hoi polloi. You know, stuff like ‘bruising the gin’, corks are somehow superior to twist-off caps on wine, or that whisky/whiskey actually ever meant anything significant. ---
**Author:** ![teela\_brown](https://avatars.discourse-cdn.com/v4/letter/t/d9b06d/32.png) [@teela\_brown](https://boards.straightdope.com/u/teela_brown)\ **Post date:** [July 26, 2019, 8:41pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/4 "2019-07-26T20:41:19Z")
We do French press, and I’ve read about that “blooming” stuff. Bah. What do I care at 5 a.m.? I just want a strong cuppa coffee as soon as possible and am not about to add any more time to the brewing process. ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [July 26, 2019, 9:09pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/5 "2019-07-26T21:09:45Z")
If it don’t bloom by the time I get my mug out, too bad. I’m drinking it anyway. ---
**Author:** ![Ukulele\_Ike](https://avatars.discourse-cdn.com/v4/letter/u/df788c/32.png) [@Ukulele\_Ike](https://boards.straightdope.com/u/Ukulele_Ike)\ **Post date:** [July 26, 2019, 9:12pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/6 "2019-07-26T21:12:53Z")
Letting the coffee “bloom” makes sense to me, on the same level that my being a Scorpio sun sign means my favorable day of the week is Tuesday. But it only takes a few seconds to do it, so why the hell not? ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [July 26, 2019, 10:01pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/7 "2019-07-26T22:01:12Z")
I don’t know about all that. But I do know that the longer the grind is wet the more caffeine will soak out of it, so I’m game to do it. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [July 26, 2019, 10:03pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/8 "2019-07-26T22:03:29Z")
I’ve switched over to cold brew here, so it’s irrelevant to me. I urge all coffee lovers to give it a try. NOT the commercial products (tho that’s the one starbucks product I think they do well) but making it at home. [/hijack] ---
**Author:** ![Zyada](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zyada/32/3028_2.png) [@Zyada](https://boards.straightdope.com/u/Zyada)\ **Post date:** [July 26, 2019, 11:35pm UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/9 "2019-07-26T23:35:47Z")
By “pour-over” you use something like [this](https://www.google.com/shopping/product/9108638552204354985?q=melitta&safe=active&client=firefox-b-1-d&biw=1703&bih=812&prds=epd:13492933933490661414,prmr:3&sa=X&ved=0ahUKEwiPqvOq39PjAhWPUt8KHTrlCyQQ8wIIiwQ)? I’ve had one of those for decades, and always wet the beans and given it a few seconds before pouring over the rest of the water, but I always thought it was to let the grounds get wet thoroughly so you would get stronger coffee. However, I’ll bet it doesn’t make any real difference in flavor. I wonder if Cook’s Illustrated has tested that? ---
**Author:** ![HyacinthBucket](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hyacinthbucket/32/3063_2.png) [@HyacinthBucket](https://boards.straightdope.com/u/HyacinthBucket)\ **Post date:** [July 28, 2019, 12:44am UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/10 "2019-07-28T00:44:05Z")
> [@Zyada](#): > > By “pour-over” you use something like [this](https://www.google.com/shopping/product/9108638552204354985?q=melitta&safe=active&client=firefox-b-1-d&biw=1703&bih=812&prds=epd:13492933933490661414,prmr:3&sa=X&ved=0ahUKEwiPqvOq39PjAhWPUt8KHTrlCyQQ8wIIiwQ)? > > I’ve had one of those for decades, and always wet the beans and given it a few seconds before pouring over the rest of the water, but I always thought it was to let the grounds get wet thoroughly so you would get stronger coffee. > > However, I’ll bet it doesn’t make any real difference in flavor. I wonder if Cook’s Illustrated has tested that? They mention the process but it doesn’t look like they ever taste-tested it; > **[Coffee, Coffee, Coffee | Cook's Illustrated](https://www.americastestkitchen.com/cooksillustrated/buying-guides/448-coffee-coffee-coffee)** Sorry if anyone hits a paywall) \*How to Make Pour-Over Coffee How it Works: Place ground coffee in a wedge-shaped filter holder and pour water over it into a container below. Why We Like It: The manual drip allows the natural acidity of coffee to shine through, yielding bright, flavorful coffee. As with the French press, you control water temperature and brew time. Downside: Since you have to add water in batches, you can’t leave the kitchen during brewing. The Right Grind: Medium (like coarse cornmeal) for paper filters; medium-fine (like fine cornmeal) for metal filters. 1. Add 2 tablespoons coffee for every 6 ounces water to filter. 2. Pour 1/2 cup just-boiled water over grounds, saturating thoroughly; let stand for 30 seconds. 3. Pour remaining hot water over grounds, in batches if necessary, stirring gently after each addition.\* ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [July 28, 2019, 1:47am UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/11 "2019-07-28T01:47:13Z")
If I’m doing a pour-over rather than french press, using fresh-roasted beans, I wait for the bloom to do its thing so the froth doesn’t overflow the filter cone and make a mess. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [July 28, 2019, 1:55am UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/12 "2019-07-28T01:55:43Z")
I’m also more a French Press person but when I’ve done the pout over it does just seem practical. If you don’t let it settle before pouring more much of the grind is up in the froth and not getting poured over. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [July 28, 2019, 2:03am UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/13 "2019-07-28T02:03:20Z")
Coffee bloom is real. It’s the froth that blooms up when you pour water on coffee grounds. If you don’t manage it, some of your grounds won’t get wet enough to brew properly. You can’t just pour a little water and passively expect it to work. Pour a little, watch the grounds swell and shift, pour more over the grounds that don’t seem wet enough. French press is easier. Stir, wait, then stir again. ---
**Author:** ![Mars\_Horizon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mars_horizon/32/2804_2.png) [@Mars\_Horizon](https://boards.straightdope.com/u/Mars_Horizon)\ **Post date:** [July 28, 2019, 2:12am UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/14 "2019-07-28T02:12:19Z")
> [@Daniel Gritzer of Serious Eats](#): > > With all this gas fleeing the beans, there’s a potential problem—in order for the water to properly extract the coffee’s flavorful contents, it first has to get into the beans, which it can’t easily do when CO2 is rapidly bubbling out. But how much of a difference does it make? > [@](#): > > In test after test, blind-tasters in the Serious Eats office were able to differentiate bloomed pourover coffee from un-bloomed, proving that one can indeed detect the effects of blooming. In almost all instances, tasters identified the bloomed coffee as richer, rounder, and fuller-flavored, while the un-bloomed samples tended to have a flatter, more hollow flavor, and at times tasted slightly more acidic. A more acidic flavor makes sense in un-bloomed coffee, as it’s a sign of under-extraction—the CO2 was bubbling out while the water was trying to get in, so the water wasn’t able to extract the beans’ flavor as fully. Cite: [The Hows and Whys of Blooming Coffee](https://www.seriouseats.com/2018/07/the-hows-and-whys-of-blooming-coffee.html) (Note that blooming is apparently a pour over-only thing.) ---
**Author:** ![ThisSpaceForRent](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thisspaceforrent/32/345_2.png) [@ThisSpaceForRent](https://boards.straightdope.com/u/ThisSpaceForRent)\ **Post date:** [July 28, 2019, 3:44am UTC](https://boards.straightdope.com/t/letting-coffee-bloom/837685/15 "2019-07-28T03:44:34Z")
> [@HMS\_Irruncible](#): > > Coffee bloom is real. It’s the froth that blooms up when you pour water on coffee grounds. If you don’t manage it, some of your grounds won’t get wet enough to brew properly. > > You can’t just pour a little water and passively expect it to work. Pour a little, watch the grounds swell and shift, pour more over the grounds that don’t seem wet enough. > > French press is easier. Stir, wait, then stir again. exactly what I do making French Press coffee. I can tell the difference, that’s all that really matters.