What is an espresso shot?
Hi guys, I'm looking for some clarification on what the professional standard "espresso shot" is now. My confusion has stemmed from reading the work of Scott Rao, Jim Schulman and Ben Kaminsky regarding extraction yield and brew ratios.
In my previous job (and first exposure to coffee) we were taught to configure our volumetric machines using a measuring glass, stopping the GB5's water volume programming when the crema hits 30ml in both glasses. This programming was used for our large coffees (60ml or "double shot"), and a 22ml "ristretto" setting was used for our small coffees (44ml or "double ristretto") which would finish pouring at about 19 seconds. This way we could achieve the same espresso:milk ratio in both our 8oz and 12oz coffees. No mention was ever made to brew ratio, no one ever suggested to weigh the espresso. We used various different blends and coffees of different roast levels (and therefore different solubility) all on the same program - despite the fact that they had greatly different amounts of crema. Because of this, many of the coffees didn't taste quite right as espresso, besides the house blend which the water programming was always designed around.
I now understand why it is so important to weigh the espresso shot in grams and determine the brew ratio as a recipe for your chosen bean.
My new research has shown that in order to get the best flavour out of each single origin roast or blend, one must configure a unique recipe and brew ratio for that bean. At home I have been experimenting with the basic 1:2 brew ratio; 20g of ground coffee in a 20g VST basket and extracting 40g of espresso out. I don't have a TDS meter to measure the extraction yield % but this recipe tastes really quite nice. I too understand now that a ristretto shot is more of a 1:1 ratio.
The question I have now is how this ties in with the commercial application.
At home I have a naked portafilter. 20g of ground coffee goes into my VST basket, 40g of espresso comes into my glass; there are no spouts to split my extraction volume. Is the 40g of extraction my "shot" and therefore does the double spout used in most cafes split this "shot" into 2 servings (therefore making the notion of a 30ml shot standard redundant)? Or is my 40g espresso supposed to be 2 "shots" worth? None of the theory ever mentions this.
Sorry to make such a lengthy post, it's just been weighing on my mind. I would appreciate any clarification on the matter!
TL : DR - Is the final espresso volume at a 1:2 brew ratio the "shot" or is it supposed to be a "double shot worth of coffee" in the commercial application.
If a commercial outfit puts 20g of coffee in the portafilter you will definitely be charged for a double 20g ground coffee to 40g brewed coffee (which is approx 60mls including crema) is at least a 'double' shot (some would say it almost sneaks into a triple).
I suspect you'll find that commercial baskets are typically dosed closer to the 14g to 15g level, meaning that 30g of brewed coffee is a standard double at 'normal' extraction.
Given your 1:2 brew ratio, the number of shots reflects the amount of ground coffee used (7g = single, 14g= double, 21g = triple......ish).