I was really lucky to be able to attend the SCAE Brewmaster course held at Marco HQ a couple of weeks ago. The course in a nutshell gives someone the tools to effectively take control of their brewed coffee. The aim it would appear, from the SCAE point of view is to raise the quality of brewed coffee across Europe by creating a nucleus of “Brewmasters” to spread the good word. The ultimate target isn’t really the super speciality people, rather the average cafe, who is likely to be using as little as 30g of coffee in per litre water, and extracting every last morsel of coffee from that 30g. Nonetheless the material is hugely relevant to anyone who cares about brewed coffee quality. It was was more than just interesting for me, however, it has crystallised some thoughts in my mind about brewed coffee, particularly in relation to grinders for brewed coffee, which has been a bugbear of mine for some time.
Firstly I will say that, in general, in my (good) coffee drinking lifetime I have been drinking updosed underdeveloped coffee as outlined by the SCAE (and most other bodies). For those unfamiliar with these concepts, it basically means I was extracting less than the ideal (18-22%) amount from my coffee, and perhaps compensating for the diminished strength of such an extraction by increasing the dose. To fall within “SCAE Ideal” you need to be using between about 50g /l and just under 70g/l. The Nordic standards permit a higher dose range, the SCAA standard a lower one. With drip and press, I have pretty much always favoured finding myself at the top or just above the SCAE standard (without knowing so at the time). For Vac Pot and Aeropress, however, I have found myself using doses well in excess of any known standards.
However, I am not alone. Examples of underextracted, updosed brews are abound. In the recent Aeropress Championship two of the top 3 methods (including the winner) used a dose of 100g / l. When I duplicated these results at home, I got tasty cups, that were underdeveloped by any standard (12-14%), but fell into the ideal range in terms of strength. Take note that the palates of the judges of the aeropress championship are not to be sniffed at.
So does this suggest a kind of mass hysteria among speciality coffee folks, a laziness in technique due to increasing bean quality, or perhaps that the 50+ year old standards are inadequate?
The answer is probably not 100% any of the above, though I will admit at times finding it difficult to brew a bad cup of certain stellar coffees (hint = Aricha).
The problem though, is the Gold Cup extraction percentages presume a relatively uniform grind, the kind you might get from industrial roller grinders, and to a lesser extent some commercial / bag grinders. The physics of bean grinding, however, says that the finer the grind, the more fines (dust-like tiny particles) will be created, regardless of grinder. Whether you have a Mahlkonig Guatemala or a Rancilio Rocky this holds true. Conversely coarser grinds produce fewer fines.
Over the course of a brew these fines will overextract in relation to the normal sized grinds, typically creating a bitter, muddy taste. I’ve heard it mentioned that the fines add complexity, I would argue brew a cup of 100% fines and see how complex you find it. A turd in a swimming pool probably makes the swimming pool more complex. It seems natural enough therefore that those of us sensitive to these types of flavours , identifying them as undesirable will perhaps instinctively move to coarser grinds that produce fewer fines. When we find the mouthfeel and body lacking we increase the dose.
I’d put 95% of the blame for this trend on the grinds we use.
The other 5% perhaps is that these types of brews actually can be excellent. Punchy, intense, BIG! They may not deliver a full picture of a coffee – but does a ristretto give you everything a bean can give to espresso? It is foolhardly to merely label anything short of 18% extraction “wrong”.
My message here is not to say that 18-22% extraction is not a meritorious standard. With a good grinder, or as I have been doing at home, sieving my grinds to remove the fines, extractions in this range really sing, beautifully sweet, rounded and complex. Without sieving the grinds there was a kind of muddy overlay to the flavour profile. I do believe this is the default level to which coffee should be brewed. But we don’t all have Mahlkonig Tanzanias or Ditting K804s (yet), and if we do, when were the burrs last changed? Sieving grinds is also a pretty tedious process.
It’s apt to point out that the SCAE Gold Cup is due to undergo a process of consultation to update the standards and aims of the concept. The timescale is in the half a decade kind of region so I suspect one won’t be able to accuse to them of not being thorough. I do hope, however, that in that time we are able to move on from lamenting fines, the grinders that produce them and being drawn inexorably coarser… always coarser.