Here’s a brief post about why I aim for higher extractions.
(I have much much more to write on this topic, so be ready!)

Some people will dismiss extraction yield as an irrelevant and non-subjective method of analysis and I couldn’t disagree more.

(Some readers have found this paragraph confusing, so I’ll explain. Measuring and analysing extraction with a refractometer is, by definition, objective. Lot’s of people claim that it has nothing to do with the subjective ‘tasting’ aspect of coffee analysis. I believe this to be untrue: it has a very direct relationship to the subjective side of coffee. That claim is what I am disagreeing with here.)

Measuring extraction yield is the single most important aspect to brewing coffee. It’s bringing coffee out of the stone age and also making it more accessible. Unfortunately, there are still precious few people in the world who really understand and have a thorough working knowledge of extraction yield. If you’re not one of them, please start working towards it!

(I’ll soon be publishing a crash course for this, so stay tuned!)

I – and a growing number of respected coffee professionals – prefer coffee to be extracted above 21%. There’s a bit of contention within the industry about whether this is a good thing, and I can’t blame them; it’s all quite confusing, and the ‘new thing’ in coffee doesn’t have the best track record.

Coffee roasted well and extracted above 21% is sweeter, more transparent, richer, more focused, more approachable, and simply much more delicious than any extraction below. Since I started extracting more out of both filter and espresso coffee, I’ve been unable to move my preferences back again. Everyone else at St Ali and Sensory Lab are the same; we;ve been totally converted, and we’re never looking back.

[ It must be said that extracting coffee above 21% doesn’t instantly make it more delicious. If your roasting and brewing isn’t specifically geared towards this style of extraction, it will not taste better!]

The first step towards more extraction is making your grinder adjustment finer and using less grams per litre.
After that, you need to put some effort in. There’s lots of things that contribute to a tasty and high extraction. Most of them require a lot of work, some of them cost a little money but all of them are just plain common sense.

– use techniques like stirring and distribution that promote even extraction.
(more even = more better)
– find equipment that treats every coffee grind the same way.
(even extraction = more freedom)
– roast, re-roast and then roast it again.
(aim for more sweetness from higher extractions)
– buy green coffee that’s complex, full of character and extremely well sorted.
(well sorted, single variety, single-screen coffee means a more even extraction!)

I hope you’re getting the hint.

Hunt down every single avenue to extracting the coffee more, and more evenly. An even extraction means it’s easier to get more extraction, and more extraction equals more yums.

Here’s a little bit more detail about uneven extractions –

An uneven extraction is the hallmark of bad technique or equipment. At its worst it creates severe bitterness and sourness (over and under extraction) simultaneously. At its most benign, it creates an unfocused or muddled flavour. Most coffee professionals won’t identify uneven extraction as a fault because it is so common, but once they taste an evenly extracted coffee it becomes quite clear.

An even and high extraction is strikingly focused and transparent, and will amplify a coffee’s natural flavours; be they good or bad. If you think of an uneven extraction as a mixture of different extractions (and therefore different and muddled flavours) you will understand that an even extraction is less of a mix as it contains much more of the flavour you want (hence why I call it ‘focused’ flavour).

Another problem resulting from an uneven extraction is the tendency for baristas to under-extract their coffee. When presented with an unfavourable taste, a large majority of Baristas will tend to extract less out of the coffee to hide it. They will increase the dose, coarsen the grind or stop the espresso shot sooner. All of these things are a quick fix to reduce dryness or bitterness, but they generally create an under extracted brew. In their haste to remove the over-extracted flavours, they begin to favor a coffee that is under-extracted (ie. sour, salty, grassy, cereal-like and in the case of espresso, quite awful). The unevenness of their extraction might be a result of poor technique or a bad brewer – it’s these factors that should be addressed first, before you can change the brewing recipe.

To make decisions about equipment and technique, use extraction yield as your benchmark. If you can somehow achieve more extraction without tasting dryness/bitterness, keep doing it. The equipment that can extract the coffee more evenly will produce a higher extraction with the same parameters as its competitor.

When comparing espresso baskets and pulling identical shots in each;
the baskets with a higher extraction win.

When testing shower-screens;
the ones that produce the highest extraction win.

When testing distribution techniques;
the one that achieves the highest extraction wins.

This may seem extreme and short-sighted, but it’s how I’ve been working for the last 18 months. Everyone at St Ali and Sensory Lab who makes decisions on coffee flavour thinks like this, and we’re improving faster than I could’ve previously imagined.
Please disagree at your leisure and ignore at your peril!

After all that, it’s likely the grinder. Grinders are the most important aspect to an even and high extraction. If you want to learn more about this, read through my series ‘The EK43 – Parts One, Two and Three‘.

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