# To Bloom or not to bloom



## the_partisan (Feb 29, 2016)

I came across this "coffee science" article which seems a bit more well thought out than others, basically proving blooming has no effect on removing extra CO2:

https://www.npcoffeescience.com/post/to-bloom-or-not-to-bloom-part-2

There'll be a follow up on dissolution of all organic compounds, likely with similar results, but it hasn't been published yet.


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## JoeBL (Jun 2, 2020)

Interesting. It's so ingrained in my routine now that I think I'll keep it up unless it's proven to have a negative effect.

The 40 seconds is the perfect amount of time to rinse out my grind container 😅


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## higbert (Jun 10, 2020)

Coffee science is not necessarily coffee reality. Whatever the reasons, the bloom seems to help (though of course it could all be psychological...)


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## garethuk (May 2, 2019)

Could be that the bloom is just getting the grinds evenly wet/saturated within a short time frame which then potentially assists with the flow of water through the coffee bed once the main pour begins, or something similar. I don't know, I just do what i'm told 🙂


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## Step21 (Oct 2, 2014)

garethuk said:


> Could be that the bloom is just getting the grinds evenly wet/saturated within a short time frame which then potentially assists with the flow of water through the coffee bed once the main pour begins, or something similar. I don't know, I just do what i'm told 🙂


 That's the widely held mantra along with pouring an amount roughly equal to 3 times the coffee weight. Where did this come from?

All pourovers have a bloom phase whether a single pour or multiple.

V60 I currently pour a third of the total in my first pour - I guess it's still technically a bloom as in the coffee swells up. I notice that the colour of the output liquid darkens noticeably on the second pour, presumably picking up more solubles "missed" on the first. Each subsequent pour picks up more.

The idea is to finish before you start to pick up undesirable solubles which muddy the brew or add taste defects.

There are many ways to get there reflecting the plethora of recipes and pour regimes that you commonly come across.


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## MWJB (Feb 28, 2012)

higbert said:


> Coffee science is not necessarily coffee reality. Whatever the reasons, the bloom seems to help (though of course it could all be psychological...)


 Coffee science is recording what actually happens and its effect. You're talking about coffee opinion, lacking practical experiment, just stuff that people say.


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## higbert (Jun 10, 2020)

Sure. But so much of the coffee world is based on subjective opinion and what people say. Like every niche activity in the world, there's an enormous amount of legacy knowledge passed on by word of mouth, and far more so when the opinion is about taste and perception.


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## MWJB (Feb 28, 2012)

Step21 said:


> That's the widely held mantra along with pouring an amount roughly equal to 3 times the coffee weight. Where did this come from?
> 
> All pourovers have a bloom phase whether a single pour or multiple.
> 
> ...


 3 times the dose weight came from Scott Rao just a couple of years ago. Previously, people were also regularly using 1-2 times dose weight, or Rao & Hoffmann were using ~5 equal pours at equal intervals, when adopting this Hoffmann even wrote a post to say how he had been proven wrong when blooming, then pouring the remaining water in 2 stages...yet, what does he do now?.

I guess that 2x dose came form a hypothetical illustration in Lockhart's paper where he postulated that a brew *might* hold around twice it's own weight in water (based on one interpretation this would be a figure of 2.086 that I see regularly quoted as some kind of target, which is ridiculous). In reality, your dose will only hold about 1.5x dose, or less, at the start of a brew, the rest drops through into the cup/carafe & is not saturating anything.

Back in the time that Lockhart wrote this, the CBI recommended method was to pour all your brew water in one swift pour, with no bloom, but they showed a Curtis Gold brewer that had a compartment that held the grinds in the base of the brewer. As @garethuk states above, in a situation where you are pouring a large amount of water, all in one go, without such a compartment, pre-wetting is a good idea to stop the buoyant grinds from floating about on top of the water & failing to extract.

I bloom from 1.5x dose to 4x dose, to no specific bloom at all for a brew with a coarse grind & lots of small pulses (all of which extract similarly and have similar repeatability based on ~1000 measurements). It entirely depends on pour regime & grind size. Anyone who tells you that you need to do a specific amount, or has a logic based on this, is flat wrong.


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## MWJB (Feb 28, 2012)

higbert said:


> Sure. But so much of the coffee world is based on subjective opinion and what people say. Like every niche activity in the world, there's an enormous amount of legacy knowledge passed on by word of mouth, and far more so when the opinion is about taste and perception.


 Agreed, but coffee is like anything else, there are known outcomes from known inputs (within reason), but these are not commonly discussed, or repeated by fanboys/wizards.

Much of what is passed on by word of mouth is just noise & not real.

Taste, e.g. preference is subjective and no science/experience/practical experiment can say otherwise. We might be able to prove that a certain flavour combination is more acceptable to a larger/smaller % of a sample...but that's less relevant to many of us.


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## MWJB (Feb 28, 2012)

Step21 said:


> V60 I currently pour a third of the total in my first pour - I guess it's still technically a bloom as in the coffee swells up. I notice that the colour of the output liquid darkens noticeably on the second pour, presumably picking up more solubles "missed" on the first. Each subsequent pour picks up more.


 The very first thing washed out of your dose is the oil, if you have a fairly small amount dripping out, this will appear to have a very low coffee TDS

Here are a few examples from drip through, 12g dose, final brews ended 1.25 to 1.30%TDS:
42g drip through @ 0.64%TDS

29g drip through at 0.79%TDS

I suspect you'll find that a sample of the last drips out of the brewer is, again, lighter in colour.


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## malling (Dec 8, 2014)

April don't bloom their coffee, they said a recipe should follow what the roaster intended with the coffee. So they made a two pour recipes with the April brewer with no bloom.

bloom like allot of things in the coffee industry isn't really constructed on science and scientific findings. Allot of it is done because someone did something and found it to be helpful/successful. Basically you can do what you like there are no golden rule, just look at recipes from past winners, these are all over the map. Some use no bloom others do, some uses small predictable pours with the same time interval others pour once or twice, some pour close to the surfaces with high flow others from high up with low flow. Etc. etc. Do what pleases you, everyone else is.

But most coffee science would not survive a true scientific examination, sad but true.

Rao say something one day and then the next he dos the exact opposite, who is listening to him anyway.


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## Step21 (Oct 2, 2014)

malling said:


> April don't bloom their coffee, they said a recipe should follow what the roaster intended with the coffee. So they made a two pour recipes with the April brewer with no bloom.
> 
> bloom like allot of things in the coffee industry isn't really constructed on science and scientific findings. Allot of it is done because someone did something and found it to be helpful/successful. Basically you can do what you like there are no golden rule, just look at recipes from past winners, these are all over the map. Some use no bloom others do, some uses small predictable pours with the same time interval others pour once or twice, some pour close to the surfaces with high flow others from high up with low flow. Etc. etc. Do what pleases you, everyone else is.
> 
> ...


 How can a roaster deliberately intend for their coffee not to be bloomed? What changes do you make in a roast to ensure that April coffee only brews as intended in an April brewer?


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## malling (Dec 8, 2014)

I think it's the other way round, they wanted a special profile, that profile requires a different way to brew the coffee, this again lead to the april brewer.

it's not uncommon that you brew very light roasted coffee with no bloom.


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## Step21 (Oct 2, 2014)

malling said:


> I think it's the other way round, they wanted a special profile, that profile requires a different way to brew the coffee, this again lead to the april brewer.
> 
> it's not uncommon that you brew very light roasted coffee with no bloom.


 The April brewer just looks like a flat bed brewer with a large single hole. The video shows them pulse pouring like any other device. I'm sure it would be an interesting brewer to try but saying that you need this particular brewer to get the best out of our beans sounds like marketing hype to me.

Pretty sure a few competitions have been won with the V60 in the past.

It would be interesting to hear from anyone who has one of these as to how it compares to say a Kalita.


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## malling (Dec 8, 2014)

Step21 said:


> The April brewer just looks like a flat bed brewer with a large single hole. The video shows them pulse pouring like any other device. I'm sure it would be an interesting brewer to try but saying that you need this particular brewer to get the best out of our beans sounds like marketing hype to me.
> 
> Pretty sure a few competitions have been won with the V60 in the past.
> 
> It would be interesting to hear from anyone who has one of these as to how it compares to say a Kalita.


 It is fundamental a flat bed brewer with a large single hole, but any brewer has different flow rate, for example the Origami has a much different flow rate than that of a Wave, and those it gives a difference in the cup.

you can pulse or not, it's just a brewer! But they made it because they wanted to get a certain result. No it's not a given you can replicate it with a wave due to flow rate.

a wave also have a much higher coffee bed than both an Origam and April.

loveramics have just released 3 brewers that looks the same but according to them due to the internal pattern design they have 3 different flow rates this again should lead to a difference in the cup.

I think you are missing the point, to achieve what they intended with their coffee, is really not the same as get the best out of the coffee. In the end this is what all roasters want.

Is it a marking stunt, well, obviously it is also that, name one that isn't.


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## jaffro (Oct 6, 2015)

malling said:


> It is fundamental a flat bed brewer with a large single hole, but any brewer has different flow rate, for example the Origami has a much different flow rate than that of a Wave, and those it gives a difference in the cup.
> 
> you can pulse or not, it's just a brewer! But they made it because they wanted to get a certain result. No it's not a given you can replicate it with a wave due to flow rate.
> 
> ...


 That's interesting.

Personally for different flow rates I have the December dripper. I don't play with it that much really, generally I'll use it wide open for things like natural Ethiopian beans where the drawdown takes ages.

Can't see why you'd ever want separate brewers for different flow rates... Bit of a ball ache!


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## MWJB (Feb 28, 2012)

jaffro said:


> Can't see why you'd ever want separate brewers for different flow rates... Bit of a ball ache!


 If you're making brews of the same size, grind & ratio it's easy enough to get them to extract the same - handy if you run out of papers for one but still have them for another.

If they did have greatly differing flow rates (this would only be because you poured at a speed to create this) you would get very different extractions & generic malfunctions.


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## malling (Dec 8, 2014)

jaffro said:


> That's interesting.
> 
> Personally for different flow rates I have the December dripper. I don't play with it that much really, generally I'll use it wide open for things like natural Ethiopian beans where the drawdown takes ages.
> 
> Can't see why you'd ever want separate brewers for different flow rates... Bit of a ball ache!


 I own both a Wave, Origami and April, all are usefull and one could easily live with just one as these. The Irony is that I find the metal Wave 155 to be faster than Origami, I always found it a bit ironic that people complaining about flow restrictions of the wave as it drain fast enough, in fact so much that the max flow is so high that you would never even consider to use it to it's fullest.

what determines the flow in a brewer is much more complex, people often over exaggerate the exit effect as a restrictive force when brewing.

I don't think the idea is to have different brewers with different flow rates, but choosing the one with a flow rates that suits your preferences. The one with fastest flow rate would allow you to grind finer, for some that is a desirable characteristic, others might want a brewer with slower rate so they can use a coarser grind. I think that is the logic behind it.

this is also the benefit of the december, not that it can restrict flow but that it allows you to use a finer or coarser grind


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## jaffro (Oct 6, 2015)

malling said:


> I own both a Wave, Origami and April, all are usefull and one could easily live with just one as these. The Irony is that I find the metal Wave 155 to be faster than Origami, I always found it a bit ironic that people complaining about flow restrictions of the wave as it drain fast enough, in fact so much that the max flow is so high that you would never even consider to use it to it's fullest.
> 
> what determines the flow in a brewer is much more complex, people often over exaggerate the exit effect as a restrictive force when brewing.
> 
> ...


 Yeah totally see your point.

I was thinking you meant people could have multiple of the same brewer just with different flow rates for different beans, which seemed odd because a December gives you the flexibility. I see what you mean now, you could just buy the one that suited your preference.

I had a kalita wave 185, then when I got a December I sold the wave on. Didn't see the need for both! I found the wave to be a bit slow mostly on the final drawdown, but not to the point that it was an issue at all. The December on its mid setting feels like a kalita, then I just open it up fully for beans that would otherwise need a really coarse grind.

I do keep meaning to see if there's much difference in taste between grinding coarse and restricting the flow vs grinding fine with the flow fully open. Like you say, seems like there are a lot of factors that would perhaps contribute!

Cool, that you a few of them though! Origami is probably the prettiest, but do you have a favourite?


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## malling (Dec 8, 2014)

I prefer the Origami at the moment, not much difference with the April, but has less mass so results in less heat loss, a thing that also effect draw down.


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