# Bloom control



## Step21 (Oct 2, 2014)

How best to deal with volcanic bloom in pourover?

My home roasts are typically producing more vigourous bloom than i'm used to compared to bought roasted coffee. They seem to have more CO2 to release. I'm noticing that even 3 days post roast some of them are still blooming very substantially.

I'm getting decent enough brews but noticing that extractions subsequent to the first one are typically reducing. My standard is to give 40sec bloom time. The first part of the post bloom pour sees the bloom rise up even more and i'm pouring slowly to try and saturate everything.

Should i simply extend the bloom time? I don't do any stirring of the bloom - would this help? Different pour strategy?

I could give the coffee more time to settle but i'd have thought 3 days post roast was adequate.


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## Stevebee (Jul 21, 2015)

I know someone has suggested in the past letting the coffee 'rest' after you grind the beans instead of the norm of brewing straight after grinding. Don't know if this works but hope there are some good suggestions as I have the same issue on some of my home roasts as well, especially if my stocks are low and I'm using the 1 or 2 day ones.


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## aaronb (Nov 16, 2012)

Extend rest time, leave the beans for a week?


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## Scotford (Apr 24, 2014)

Are you fully developing your roasts?


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## Step21 (Oct 2, 2014)

Scotford said:


> Are you fully developing your roasts?


It's very possible it is something to do with the roast. I'm just having a bit of fun with manual roasting at the moment, so not using a machine with profiles etc... It's hit and miss but i'm pleasantly surprised by the sweetness and flavours i'm getting in the cup most of the time. Some of the brews can exhibit a touch of dryness on the finish which i assume is a flaw in the roast process.

I'm not sure exactly what you mean by "developing the roast". I'm generally taking my roasts a little short of 2nd crack?


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## Step21 (Oct 2, 2014)

aaronb said:


> Extend rest time, leave the beans for a week?


No tweak to technique that could help? I've heard phrases like "riding the bloom" used in pourover but i'm not really sure what that actually means or whether it has any basis.


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## Step21 (Oct 2, 2014)

Found this study which might be relevant:

Department of Food Science, University of Guelph, Guelph, On, N1G 2W1, Canada

Food Research International 01/2014;

*ABSTRACT* CO2 is one of the major gases formed during coffee roasting, which has important implications on coffee's quality and packaging requirements. In this study, the residual CO2 content and CO2 degassing behavior of an Arabica coffee processed using a fluidized bed roaster, as affected by the roasting temperature-time conditions, were investigated. The results showed that positive correlations existed between the degree of roast (expressed as lightness value) and residual CO2, implying that lightness could be used as an indicator of initial CO2 content in roasted coffee. At the same degree of roast, coffee roasted with high-temperature-short-time process had significantly higher CO2 degassing rate than those with low-temperature-long-time process. Moreover, the CO2 releasing rate increased with the degree of roast. The degassing rate of CO2 in ground coffee was highly dependent on the grind size and roasting temperature, but less dependent on the degree of roast. The different degassing behaviors observed between roasted coffee samples were explained on the basis of chemical composition and microstructural differences.


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## Scotford (Apr 24, 2014)

Step21 said:


> It's very possible it is something to do with the roast. I'm just having a bit of fun with manual roasting at the moment, so not using a machine with profiles etc... It's hit and miss but i'm pleasantly surprised by the sweetness and flavours i'm getting in the cup most of the time. Some of the brews can exhibit a touch of dryness on the finish which i assume is a flaw in the roast process.
> 
> I'm not sure exactly what you mean by "developing the roast". I'm generally taking my roasts a little short of 2nd crack?


Sometimes when I get slightly underdeveloped coffees (we'll get to what it means in a moment), I find that the bloom goes a bit haywire and erupts like a volcano.

Developing a roast is where you're properly heating the beans to have altered the cell structure sufficiently enough that the entire bean is cooked consistently all the way through and as little green matter is left.


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