Stupid Question v. 1.0

Jammer Six

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Sep 8, 2022
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I have a Breveille dual boiler, and I have some stupid questions.

On the front of it, it has a gauge laid out in bar, that shows the pressure. (The steam pressure being applied to the coffee, I assume.)

What do I do with this information? Why do I want to know this pressure? What does it tell me about my coffee?

Do I want low pressure or high pressure?
The pressure seen, is the amount of bars required to push the hot water through the grinds. A bar is roughly 14.7 pounds per square inch pressure. If the pressure is too low, the water just rushes past the grounds, and does not extract the flavor from the beans. If the pressure is too high, the water moves VERY slowly past the beans and can "over extract" the harsher elements of flavor. (You will note I didn't give a specific number of "bars" for the ideal cup, as this will likely start a "spirited discussion" on this topic. Generally 7 to 9 bars is considered a great starting point.)

You can use that pressure reading to let you know if you have ground too fine, and/or packed them too tightly. In the other direction your grounds are too coarse, or too lightly packed. The reading is very diagnostic. When you have the double shot filter inserted in the portafilter handles, start with about 19 grams of coffee, and start your tuning on grain size and packing from there. The length of time to brew 2 ounces is also important. A "pull" which is too fast will tend to taste sour, a pull which is too slow can be astringent and bitter. I am going to avoid a specific number of seconds, to avoid the same "spirited debate" mentioned earlier. (Many people will say the ideal pull takes about 25 to 30 seconds.)

This will mean you will need a scale to accurately determine your quantity of grains. Depending upon the type of bean, one scoop will be heavier or lighter than the desired amount.

Probably the best approach is to find an experienced espresso person in your area, who can help you dial in your brewing process. Perhaps they can tune your machine, with a specific bean/grind/tamp/brew time... to give you the much desired "God Shot".

Good luck!
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