Dear Alan, I've recently purchased an Aeropress and love the original Aeropress recipe (80C water, 10s stir, dilute in cup) since it always turns out very sweet. You've mentioned that a Brix meter is the way to go. Would you recommend a combination of Brix, TDS and pH measurements rather than just a Brix meter? I'm guessing that this should be able to log out influences of grind, temperature, time, etc to the acidity, sweetness, nuttiness, etc in a more rounded fashion. The intent is to make a recipe which is balanced on all fronts – fruit, nut, chocolate, spice, etc. Thanks a ton, Atig – From Atig B.

I don't recommend an old Specialty Coffee Association TDS meter, which was a conductivity meter. The most accurate way to measure TDS is with a refractometer. A Brix meter is a refractometer calibrated in the Brix scale. To convert Brix readings to TDS, multiply Brix by 0.85. You can also buy a refractometer calibrated in TDS. Two products are Atago Coffee and VST. Regarding pH, that would measure acid. You'll find that the lighter the roast the lower the pH, which means the higher the acid. This is "chemist's acid". The word "acid" is also used to describe a coffee flavor note.