# Bypass Brewing



## fluffles (Sep 4, 2012)

I had been considering some of the comments I've seen recently on Barista Hustle around the whole fines=good argument and thought I would conduct a little pour over experiment.

My typical grind setting on the EK for a pour over is between 7 and 8 o'clock on the dial. For a 15g/250g brew this typically gives me an EY of around 21.00-21.50%.

In order to increase the number of fines (and, I suspect, reduce the difference between the smallest and largest grind sizes, though that's only an assumption on my part) I thought I would try and brew the same extraction at a finer grind setting.

I've now had a few cups with the grind setting around the 10 o'clock position and brewed at 15g/200g. This has resulted in cups with a similar EY, but of course much higher TDS (1.85 ish). I've then diluted the brew with hot water down to a more normal TDS.

Effectively I have brewed the same coffee to the same TDS and EY but with a finer grind setting. The results have been tasty, the cup this morning of the April LSOL was the best I'd tasted it.

I'm not making any great claims that this is a better way to brew, but I am encouraged to continue the experiment. Has anyone else been down this path? Probably requires a refractometer otherwise it's easy to get lost.


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## MWJB (Feb 28, 2012)

I alternate between 2 drip brewers, one a fine grind, one filling pour, all in in 10seconds. The other with a coarser grind & 9 pulses of 25g. Av. EY is about the same (20.36 to 20.31%).

The finer grind brews can be more syrupy in mouthfeel, the coarser brews can be lighter in body. I haven't seen a clear swing in preference for one over the other.

The coarser brews are more repeatable & span a smaller range of EYs & brew times. I suspect because less small particles are controlling the flow & therefore skewing the brew time.

Grinding finer might not change the distribution greatly, just replace more of the particles at the extremes with smaller ones over larger ones. I don't see an easy way to maintain a constant av. grind setting and just increase fines without reducing boulders, without using 2 different grinders?

I think it's more that fines are inevitable & not necessarily as evil as previously painted. "More" fines, as in an excess, can ruin even a drip brew as it can override sweetness. Oversize particles do more harm (outer layers over-extract). Removing fines from an immersion can make it much cleaner & sweeter. A bed/puck that is ground too fine will eventually under-extract as water won't permeate it properly, suggesting that there isn't a great deal of leeway to explore here.

There is also some confusion, as when you look at a grind distribution by particle count alone, the average um immediately drops compared to volume, or weight. So a grind with mostly 15um particles would be 'fines city' when looked at as volume/weight, but the same grind distribution when viewed as volume weight it might be 230um average. Two ways of interpreting the same thing.


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## antonivnk (Sep 24, 2016)

fluffles said:


> I had been considering some of the comments I've seen recently on Barista Hustle around the whole fines=good argument and thought I would conduct a little pour over experiment.
> 
> My typical grind setting on the EK for a pour over is between 7 and 8 o'clock on the dial. For a 15g/250g brew this typically gives me an EY of around 21.00-21.50%.
> 
> ...


Could you please specify the amount of added water and total brew time for your method?


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## Scotford (Apr 24, 2014)

Okay. With my Bunn ICBA, I have a 5% total brew bypass setting which shoots 5% total brew water down the side of the basket and directly into the urn. I find that this prevents a load of oversaturated grinds and actually increased ext by a (not negligible) fraction. I'm putting it down to longer contact time of a column of water above the bed as there's more standing brew water softly extracting instead of a forced movement downwards.


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## Scotford (Apr 24, 2014)

N.B. This is only on brews of 2l plus.


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## fluffles (Sep 4, 2012)

antonivnk said:


> Could you please specify the amount of added water and total brew time for your method?


I've been doing 15g/200g as follows: 50g bloom for 30 secs. Pour up to 125g, give it a little swirl and short pause then pour up to 200g finishing around 1m40s, everything is drained by around 2m50s. Coming out at 1.85 TDS, then adding 50g hot water bringing it into the 1.40s TDS range.


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## fluffles (Sep 4, 2012)

This has sort of come about because I've noticed that some others (including local cafes) seem to be brewing at a finer setting than me. I have the benefit of a refrac, so I'm not at all paranoid that I'm under extracting or anything (it tastes not so good if I grind finer and keep the recipe the same). I guess this could be due to the water I'm using, I don't know. So I thought I'd experiment with a finer grind but without over extracting


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## MWJB (Feb 28, 2012)

Could be that the smaller weight of brew water is easier on the particles that would otherwise be over-extracting? Even though you may not be making big changes to the distribution profile (a guess on my part) you are still reducing the overall grind size, so outliers may be in similar proportion (maybe more skewed to fines) as before but an overall narrower distribution from 1um up?

Would be good to see what you find long term, over a range of coffees.


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