A post inspired by David Walsh’s lecture on NBC2012 regarding coffee extraction
Okay, so we talk about brewed coffee. There are rules, there are commonly agreed standards how to brew it and everybody brews it. How do we define our standards, what ideally extracted coffee is, what makes your cup of coffee good – we can indeed discuss much about it. These norms change as time goes, and people change their expectations from coffee as well. It’s a shame that most of the time coffee is being drunk for its functional qualities, than its taste, but this fact is slowly and surely changing. People are starting to realize this drink is not supposed to taste bad, but the opposite – it can have all different aromas and flavors, just like wine. But let’s get back to coffee.
So how did we shape these standards:
At the very beginning coffee was eaten, then wine was being made from it and only around the 11th century it started to become more like a drink. Then the invention of the coffee grinder came and soon enough in 1711 in Paris the practice of infusion began. Towards the end of 19th century in France the used ratio was a 100 grams of grounded coffee per liter. Meanwhile in the US you would drink coffee with coffee to water ratio as less as 14 grams per liter, you can imagine the difference in the taste, right? During WWII the development of the brew stops almost completely, except that the common recipes changed and the amount of used coffee per liter in the US doubled. After the war the Coffee Brewing Institute was formed and it started publishing a lot of research in this area. Also there was one study by the Midwest Research Institute that said region of optimal taste is between 18% and 22% extraction and since then this information was adopted from every coffee association.
And this was confirmed from the quite recent Gold Cup Research, part of the Gold Cup Programme launched by the Specialty Coffee Association of Europe. However, this range of optimal taste is not that tight, 48% of the participants selected their most liked coffee with extraction rate out of this bounds. So when we talk about preferences the picture gets bigger, right? There are not set boundaries of which you can like and which you cannot, this studies just show us that the peak of preferences is between 18% and 22% of extraction. But still, I believe that everyone should know the “standards” and only after that should be able to say what one’s preferences are.
For me, I enjoy playing with the variables when brewing. It’s interesting how the taste changes when for example you do a stronger brew, but you don’t let it extract for long, or change the grind, or even the water. I have to admit that as a mad scientist, I’ve had terrible experimenting sessions and sometimes the concoction has not been so pleasant to drink, but hey, that’s how you get to know coffee better. I like finding these differences, because it makes me more knowledgeable about the brew. And the good thing is that there’s always more to discover!