# Manual pourover flow rate



## MWJB (Feb 28, 2012)

Looking back over my pourovers (10-20g doses, 60-70g/l) I have noticed that the bulk of preferred brews fall between an average flow rate of 1.2 to 2.0g/second, with the highest incidence of brews I really liked falling between 1.4 & 1.6g/sec.

By flow rate, I mean the time that there is significant output from the brewer, so if you're blooming for 30seconds of a 3:00 brew & only see a couple of drips in that first 30 seconds (I tend to bloom with a little under 2g/g), your flow starts at 0:30 for 2:30. Conversely, if you are starting with say 20% of your brew water (adding another 20% every 30secs) & are getting reasonable flow straight away your flow is over the full 2:30 of the brew time. This also assumes the brewer drains out at the end of brewing, rather than whipping away the filter & grinds early whilst there is still water above the bed, also assumes reasonable technique & evenness of extraction.

E.g. 15g dose, 250g of brew water, 218g final output after 150seconds of flow: 218/150 = 1.45g/sec.

It strikes me that this could potentially be a way to roughly dial in grind/tie up grind, pour regime & brew ratio?

You need to weigh both brew water added & brewed coffee weight.

I'd be interested to see what others find?


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## Mrboots2u (May 10, 2013)

Ok il weight brew water in and out

So I'd need to record bloom and how long the total pour took?

Does this total time mean when nothing drips from the filter at all ( say in a chemex )


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## MWJB (Feb 28, 2012)

Mrboots2u said:


> Ok il weight brew water in and out
> 
> So I'd need to record bloom and how long the total pour took?
> 
> Does this total time mean when nothing drips from the filter at all ( say in a chemex )


Total brew time would be from when you add the very first drops of brew water, but if blooming for 30-45secs with virtually no flow (out from the filter), you would deduct the bloom time to establish flow time/rate. I guess what I'm saying is that 2 recipes, one with a bloom stage & another that goes straight in, may seem to have different "brew times" but flow time can end up similar.


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## jeebsy (May 5, 2013)

Like preinfusion?


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## MWJB (Feb 28, 2012)

Sure, like preinfusion.


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## fatboyslim (Sep 29, 2011)

I see very little merit in measuring pour overs in such a way. 18g in 3:30 adding 280ml assuming a 40 second 40g pre-infuse says it all. I believe my ideal flow rate to be around 1.4g/s however.

This information is of very little use considering the huge variation in grind consistency at coarser grinds, and the evenness of pour/extraction being the key factor and almost immeasurable without a refractometer.

Who cares about your flow rate if you didn't pour evenly and manage to extract properly via the pour.


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## MWJB (Feb 28, 2012)

fatboyslim said:


> I see very little merit in measuring pour overs in such a way. 18g in 3:30 adding 280ml assuming a 40 second 40g pre-infuse says it all. I believe my ideal flow rate to be around 1.4g/s however.
> 
> This information is of very little use considering the huge variation in grind consistency at coarser grinds, and the evenness of pour/extraction being the key factor and almost immeasurable without a refractometer.
> 
> Who cares about your flow rate if you didn't pour evenly and manage to extract properly via the pour.


Adding 280g only tells anything if you tell us how you add it & how fast/uniformly. For 18:280 to "work" & get you in the box as a ratio, grind needs to be tied in to flow rate. The gross amounts just put you on the brew line...could be under/over, somehow you need to tie in another element to pin down your region of interest.

Sure, it can't account for grind consistency, but then, what can? A refractometer can't tell you if an extraction is even, it doesn't pour for you either. One of the bigger variables is grind consistency & how that affects flow through the bed. Extraction may be largely driven by that rate of flow & identifying a grind from your specific grinder that facilitates an identifiable rate?

Specific preferences might only be +/-1% ext yeld, you need a refractometer to identify that kind of margin, or indeed to know what your yield is at all...there's no substitute for actual measurement, but for a given grind & method, also identifying your rate of flow (working out a consistent pour regime) can help you hit your targets with Coffeetools too.


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## Earlepap (Jan 8, 2012)

When using the Technivorm, since I've no control over pour or temperature, it's only the grind that I alter between brews. Other than taste, I'll consider the time it takes to drain and what the bed looks like once drained to figure out whether to go coarser or finer.


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## MWJB (Feb 28, 2012)

So, I gathered a bunch of publicly available V60 recipes between 10g & 20g dose, added a couple of my own (different ones, so as not to skew the number & variety of recipes), averaged them all out, topped & tailed the outliers and got parameters of 14g dose, 225g brew water, and a brew time of 2:15 plus bloom, 1.47g/s. (My own target is a bit lower than this, but what's the fun in just reinforcing your own preference, I wanted to see what the common consensus led to). 95C in kettle at bloom.

I also ended up swapping around my Lido1 & 2 between work & home, so it was good excuse to dial the Lido 2 in for V60.

Attempt 1: 1 full turn on the grinder, 30s bloom, 3 pours, brew ended 2:30 (1.68g/s) & 14.8% extraction. Pale, weak, strawy, but not offensive.

Attempt 2: Same grind, split the pours into 6 after the bloom, to slow the brew down, ended 2:37 (1.58g/s) & 15.9% extraction. Still weak, but better & a real slug of sweetness towards the end.

6 pours means adding water every 20 seconds after the bloom, so things were as hectic as I'd care for, time to adjust grind, went to 0.75 turn.

Attempt 3: Still 6 pours, ended 2:50 (1.43g/s), 18.68% extraction. Now we're talking! Good rich colour & mouthfeel, sweet from pretty much the first sip & just got better. Probably a little room for improvement, but a pretty good spot from which to stop & admire the view.

Sure, there's a bit of leeway regarding when you decide the brew ends (fully exposed grounds was the time quoted, then left to drip for a moment or two). I'm not suggesting that these are guarantees that will result in the desired extraction, just fleshing out the mechanism.


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