# French press - updosing...



## MWJB (Feb 28, 2012)

....can anyone please remind me, what is the logic for updosing the French press (with the caveat that whatever dose you prefer is good for you)? I seem to remember a point about coffee, rather than water, being trapped in the grounds and a subsequent drop in TDS...but the more I think about it the less sense this makes with regards to getting a good extraction.


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## garydyke1 (Mar 9, 2011)

I guess there will be more water and extracted coffee liqour stuck at the bottom with the silt. Wasnt this a topic on a tamper tantrum talk ?


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## MWJB (Feb 28, 2012)

Thanks Gary, not aware of the Tamper Tantrum talk you refer to?

So there's coffee liquor trapped around the grinds that doesn't make it into the cup. But how does this affect the yield/TDS of what has bean extracted & does make it into the cup...e.g. if you made a Chemex of a similar TDS but left a bit in the carafe, you have "trapped coffee" (as well as what is retained in the grinds), but no effect on the cup. Ditto re. a syphon/Aeropress/Clever Dripper, it's coffee trapped around the grinds?

I get that the extraction may be slow in the FP & if brewing to order, you don't want to make customers wait for half an hour, so updosing boosts the perception of strength at the expense of extraction, within a reasonable timeframe. But at home, if we have time to spare, might we not aim to dose a little less & wait a little longer? I'm not suggesting one way is right, the other wrong, just that the environment & time constraints might factor in how we brew?


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## garydyke1 (Mar 9, 2011)

..or maybe it was a presentation at the Nordic barista cup , hmmmm. My memory fails me

Using a refractometer and VST Apps' MoJoToGo, I've been measuring strength and calculating the extraction yield of my brews. However, in recent talks with VST Owner and all around science guru, Vince Fedele, he introduced me to the fundamental difference between extraction yields in drip brewing and immersion brewing. He has even included options in his newest software versions that account for the difference. It all has to do with what is left behind in the bed of coffee grounds.

Imagine for a moment slowly pouring water over a sponge that has been loaded with 10 drops of food coloring. If you continue to pour about 1 liter of water over the sponge and catch that water you'll be left with a sponge full of mostly clear water and a container full of dyed water. Now take that same sponge (reloaded with the 10 drops of dye) and instead of pouring the water onto the sponge just immerse it in the water for the same amount of time it took you to pour in the previous experiment. The dye will still dissipate into the water but when you remove the sponge it is not filled with clear water - it has dye remaining in it.

The same basic principle happens in immersion versus drip brewing in coffee. So if you are calculating extraction yields after measuring strength of your immersion brew there has to be a differential included for the stuff that gets left behind in the coffee grounds. Vince has applied his brainpower and time to figuring out this difference and has included the backend calculations in the latest versions of his MoJoToGo app and desktop software. A whole lot of time gets eaten up with the oven drying spent coffee grounds (the most accurate method). But, this is what Vince did multiple times to ensure his calculations were accurate.

Vince also notes that to account for the coffee solute left behind in the spent grounds you must increase the amount of coffee used to reach the desired strength. I remember hearing early on in my coffee days that when you brew a press pot that you add "a little more coffee for the pot" so that it tastes as strong as your drip brew. So, what many immersion drinkers have been doing and tasting for years is correct.


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## Earlepap (Jan 8, 2012)

I like the sponge analogy, that's pretty much how I'd come to understand it. I tend to like 64g/L in french press.

I noticed from following the brewers cup twitter feed - shoot me now - that a lot of competitors using immersion brewing were using massive doses, I think someone's was 90g/L?! That said, the tweets only contained the parameters, not technique so there may have been some jiggery-pokery to even things out, and an explanation in the presentation I'm sure. Shame they didn't live stream it.


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## Earlepap (Jan 8, 2012)

Whoops double post; forum freaked out and said it hadn't posted.


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## MWJB (Feb 28, 2012)

Thanks guys.

Yes, I remember the video of Vince Fedele's talk at NBC, but that seems to be set as "private" now & I can't access it.

I think Mark Prince recommended 80g/l with a skim, James Hoffmann a little less with a break, stir & skim.

Looking back, I have had good cups (by my reckoning at least) at anywhere from 60g/l to 70g/l, and also typically tend to aim for 64g/l...but that's with a

But my experiences with the Sowden & Clever Dripper have given me my best brews at a shade under 60g/l....I'm really just trying to pinpoint what differentiates these from the FP in terms of brewing dynamic...and still struggling a little with that (brew time being no object).


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## Earlepap (Jan 8, 2012)

Maybe since the lower dosing with the CCD would help with the inherent low extraction issues?

I don't know how the sowden works, or even what it looks like


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## MWJB (Feb 28, 2012)

http://www.sowden.co/pages/softbrew.html

It's the easiest brewer I have used to get a good strike rate, grind very coarse (just to keep the solids down, there's always a bit of sludge in the pot, but only light dust in the cup), 30-40minute steeps...and then some stirring, taste...then a little bit more stirring, taste...then nectar! I use 63g/1140g water (+/- 10g on the water, as I fill to line), or ~55g/l. Slowbrew would be just as apt as Softbrew ;-)


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## MWJB (Feb 28, 2012)

French press again - Ground as coarse as I could on the Rocky, 55g/l, kettle off the boil (tap water 280-290TDS by meter), wet with 3g water per g of coffee, swirl, fill, stir to ensure all grinds are wet, place plunger on top & steep for 35 mins. Stir the grounds to bring up the extraction & taste between stirs, then filtered through a Chemex paper so I wasn't thrown off by any bittering solids in the brew - very nice brew, a little weak, lukewarm due to heat loss.

Tried again, aimed for 58g/l, overshot at 57g/l...same procedure - stunning, great clarity of flavours, but lukewarm.

I'll give it another bash with the double-walled Bodum, but obviously the single walled glass FP's can't retain their heat well enough for a hot brew after such a long steep (unlike the Sowden). I personally don't mind lukewarm coffee, especially when it's as "gulp-able" as this.


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## Earlepap (Jan 8, 2012)

What's the purpose of steeping it for so long? Surely after ten minutes there's not a lot happening extraction-wise until you start stirring at the end.


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## MWJB (Feb 28, 2012)

Apparently not...there still seems to be "stuff happening". I don't have any reinforcable technical explanation, but I have found that steeps of under 20mins with a similar grind with the Sowden are very much under, then stir, stir, stir, stir and it's not so easy to hit the sweet spot. With the long steep (30min+) it just seems easier to coax the brew along a little more gently and hit the nail on the head. The porcelain Sowden retains heat much better, but it should work just as well with a better insulated FP.

At a typical FP grind I'd guess that shorter steeps really aren't long enough to get the grinds evenly steeped and saturated, so that they give up their soluble solids in an even manner. I had been grinding very fine in the FP to get more even-ness accross the pot, but obviously that introduces significant filtration issues. At shorter steeps I *think* you are more likely to get varying degrees of under, bolstered by bittering solids that give the impression of the brew being farther along.

If you get a typical FP brew that tastes good then filter it, you often find it tastes more "under" than when it was unfiltered...plus a big difference from top to bottom (which some people enjoy).

Like I said earlier, I was struggling to identify what made the different steep methods require differing protocols...now I'm not so sure that they have to...just a trade off between practicality/time/suitable grind size & whatever works for you/the environment, well "works"....but that was a sublime pot at 57g/l! ;-)

I'm probably going to have to forego luxuries like carbohydrates & protein this month and save my money for essentials like a refractometer...


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## MWJB (Feb 28, 2012)

Tried again, 37 min steep, in the dual walled Bodum Columbia, still not "hot" by the time its in the cup, but not so cool as to put off the majority of forum members I'd guess, a nice quaffing temperature. I'm probably losing more heat still by Chemex paper filtering, so may drop that aspect with the very coarse grind...Brews are like a sweet, juicy iced tea. Went a bit far today (I got impatient, too much stirring), bit caramelly/nutty, but delicious. Unlike a pourover when you go to far & you can surpress acidity & juicy fruit, this method seems to keep these components intact?

A couple of things I noted were, with a long steep, the grinds will hold much more than the oft mooted "2g of water per g of grounds" (which is less for an Aeropress pressed through anyway)...today's brew held back ~3g water per g of grinds. I lost 3.34g of water per g of grinds...though some will be accounted for through evaporation. An upshot of this is that a brew ratio of 56.6g/l actually gave a cup ratio of 70g/l (22g of grinds, 314.4g beverage), or about the equivalent of a 61g/l brew ratio with a pourover. This may also be relevant to the Sowden, but it's much more of a faff to determine retention with that.


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