As a coffee trainer I have dealt with everything from long term baristas to completely new baristas, sometimes in the same sitting.  The base knowledge of each trainee coming in can vary and there is a lot of conflicting information out there about coffee so it got me thinking about what every barista should know. I think this will end up turning into an ongoing list but I think these are some of the fundamentals that have been commonly misrepresented. If you have further questions, please feel free to call us or write us!

1. What espresso is and isn’t

What espresso is-

Definition- When a restricted amount of pressurized hot water is forced through fine ground coffee the water extracts proteins sugars and oils into a delicious couple of ounces of thick caramel colored liquid.

Espresso more refers to a method of brewing that will result in a small concentrated coffee beverage. The consistency is syrupy and dense and, if properly aged and prepared, should have a thick head of rusty golden colored crema.

What espresso is not-


-a specific kind of coffee bean

-a specific roast profile (usually expected to be dark)

-always a blend

2. Quiet milk is happy milk

There are a variety of ways to steam milk poorly, but they typically fall into two categories. While they have different visual and tactile results, they share a common trait- they are both pretty noisy. The best result lies in between. It shouldn’t be completely silent, but you should only hear occasional bursts of air for the first half of the steaming process and then it should become more and more quiet. The result? Silky microfoam!

3. Grind size is everything

The wrong grind size could be compared to a great many things, but I think tuning a stringed instrument is one of the best analogies for it. You can have the best technique in the world as a musician, but if your strings aren’t set to the right pitch, then none of that matters-it will still end up a little bit off. Also, humidity, temperature and barometric pressure can cause the wood of the instrument to swell and shrink throughout a sitting which means that the strings will stretch and slacken minutely causing the pitch to shift around, needing to be chased.

The same is just as true for espresso, factoring in climate, pressure, age, blend, roast profile etc. On any given day it’s normal to have to make over a dozen small changes to your grind setting to keep the coffee in its ideal flavor range. Even if you are positive you are dosing the same, distributing properly, and tamping level and at the same pressure, if the grind is off so is the flavor. The best solution? Start tasting a lot of espresso and getting to know the telltale signs of over and under extraction.

-Holly Bastin

Coffee Trainer for PT’s Coffee Roasting Co.

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