# Immersion brewing revelation



## MikeHag (Mar 13, 2011)

Just wanted to post something about this incase anyone hasn't come across it yet. Last week at the Nordic Barista Cup talks Vince Fedele of VST spoke about how if you're using immersion brew methods then you may need to be increasing your dose to achieve the same extraction yield target as you would with drip.

Via Mr Hoffmann's site... http://www.jimseven.com/2012/08/16/vince-fedeles-nbc-talk/


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## Spazbarista (Dec 6, 2011)

...Or alternatively you could just have a cup of coffee instead


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## fatboyslim (Sep 29, 2011)

12 minutes in and I'm starting to lose the will to live. I really can't see you need this much insight just to get a 'slightly better flavour' in the cup.

Any clues as to when Vince eludes to what the topic hints at? Or care to summarise for us please Mike


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## lookseehear (Jul 16, 2010)

You could, but if you had a vested interest in brewing coffee consistently well across different brew methods - say you intended to sell said coffee to members of the public - then the information might be useful.

Sent from my Nexus 7 using Tapatalk 2


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## MikeHag (Mar 13, 2011)

Mark,

So (and I'll try to get this right, but it's still sinking in!) when you brew coffee using a drip/pourover method you make an allowance for water retained in the grinds when calculating the resulting extraction %. But with immersion, it's not water that is retained. It is coffee i.e. extracted solids that don't end up in your cup.

So to jump to some hands on brew parameters that everyone can understand even without a mojo, a 60g/L pourover brew eg chemex would need to become 69g/L if made with a french press.

But hey, as I've always said... controlled, accurate brewing isn't for everyone. I have no beef with home baristas dialing in by taste alone. I do think it's essential for professionals tho.


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## Spazbarista (Dec 6, 2011)

lookseehear said:


> You could, but if you had a vested interest in brewing coffee consistently well across different brew methods - say you intended to sell said coffee to members of the public - then the information might be useful.


Taste it fercrissakes!!!









Caveat: the older I get the more I realise that taste isn't a given even within a particular person. The exact same food or drink can taste different depending on what you've been up to. Try running a marathon then drinking some Robinsons squash, you'll be amazed at how much sweeter it will taste than normal. Coffee likewise. I was cocking about with espresso blends the other day and must have pulled 15 shots in the 90 minutes I was at it. Not one drop was actually swallowed (blatant lie) but spat out and mouth rinsed with water, for if I hadn't my brain would have started to instruct my olfactory senses to make it taste like shit.


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## MWJB (Feb 28, 2012)

Good stuff Mike. I had already come to the conclusion that some brew methods...& even differing devices within a broad method, vary with regards to dose, liquid retention in grinds & subsequently final brew volume.

Expanding on what Vince says, at a basic level any home barista can measure, I often see ~1.5g liquid/g of grinds (not 2g) retained in an Aeropress pressed all the way through (not pressing all the way can avoid this, which I think is as much of a reason to do this, rather than simply fearing overextraction - doesn't avoid wastage though) ...which means compared to drip (or an Aeropress stopped short, or left to drain the last part by gravity), more beverage in the cup & lower TDS for a given extraction yield.

E.g. With the Aeropress, I found a 6.3% brew ratio gave 7.5% in the cup not pressed through (let the last bit drip), compared to 7.1% for pressed through...which effectively makes the 6.3% starting ratio really 6% for the pressed through version (same grind, same beans, A/B tested).

Even a permanent metal filter can make a difference to a paper filter, with regards to retention & final beverage weight with drip...therefore to dosing, working back from a final "corrected brew" ratio (dividing dose weight by final beverage weight, rather than water added at start of brewing). E.g. a 6% starting brew ratio may well end up at ~7% in the cup...so I tend to look at final ratio & work back from there ...it certainly helps my consistency with brewed methods and is measurable even without a TDS meter (which would be ideal...but not within my budget for the immediate future).

For brewed I always attempt to measure:

Filter/brewer weight (rinsed if necessary).

Dry grinds.

Water added at start of brew/end of water.

Total weight of the above at end of brew time,

Total weight less wet grinds & filter (gives retention ratio)

Final beverage weight.

I did wonder how the VST Extract Mojo dealt with these "foibles"...because certain publicly available figures left me scratching my head when working back from the maths...


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## MikeHag (Mar 13, 2011)

Seems a great approach to understanding what is going on, MW, as well as helping make it taste consistently better.

As you know, I've had issues with the AeroPress. Your approach kinda supports what Vince is saying, and also helps me understand why I have found the method less than perfect.

Regarding those foible factors, the presentation also touches on new factors that have previously been brushed under the carpet during discussions of brewing. Bean moisture and CO2 content. Really interesting that 100g of freshly roasted beans could actually be only around 94g, with 6g being gas! Highlights how much impact degassing has. I guess the full impact of these factors will become more widely understood over the coming months and years, as more people understand how to use the information.


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## garydyke1 (Mar 9, 2011)

David Walshs presentation held more interest to me . Producing a cup of "brewed" coffee via a microwave or espresso machine and have them described as sweet and balanced by an advanced palate , just goes to show ...


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## MikeHag (Mar 13, 2011)

Havent seen that one yet. Sounds interesting. I can't imagine him doing it without analysing the bejabers out of it, so I presume he did the microwave in a controlled way?


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## Earlepap (Jan 8, 2012)

He leaves the instructions at the end of the talk as a teaser, alluding to it tasting good. I've yet to try it.


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## garydyke1 (Mar 9, 2011)

short video on microwave technique. Im not this technique was used for the tastings but the espresso machine one was. You need to wach the full NBC talk to understand it all


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