How To Use a Scale for Brewing Coffee

Brian Gumm

Nov 26, 2019

About a year before becoming a coffee roaster, I started improving aspects of my home coffee brewing game. First, it was buying better coffee (Specialty-grade, fresh-roasted, from roasters like us ;) ). Then came a better grinder.

The improvement I'll focus on in this post is the use of a scale for weighing out coffee and water prior to brewing. This method stands in contrast to the common use of some kind of scoop just for coffee grounds. My argument is that the use of a scale is the superior approach. First I'll explain why, then how you can make this transition.

Why use a Scale?

Why is using a scale to weigh out coffee and water important? It comes down to one thing: Consistency.

By using a scale, you can establish what's known as a "brewing ratio." For making drip coffee at home in something like the AeroPress, another pour-over device, or even an electric coffee maker - common ratios of coffee to water are in the 1:17 range. Doing this will directly correlate to how "strong" your cup of coffee is, and you can tweak your ratio depending on brewing device, whether or not you're adding milk or sugar, and personal preference.

Putting it into Practice

So what does this look like in practice? Well, first of all, you're going to need a kitchen scale, preferably one that also has a timer function. (We just so happen to sell an awesome one with the RSR logo etched on the surface!) The unit commonly used for weights & ratios in coffee brewing is grams.

Example: The 10oz "Quick Morning Cup"

Desired output: 10oz cup
Water required: 284 gr (10oz converted to grams)
Coffee required: 16.7 gr (284 divided by 17)
Brewing device/method: AeroPress (traditional method)

Pro tip: Use the "cheat sheet" at the bottom of this post to save yourself from constant unit conversions on your phone.

Weight out 16.7 gr of coffee beans & grind them (medium-fine for the AeroPress)
Put the grounds into the AeroPress
Place your mug with the bottom half of the AeroPress onto the scale
Tare the scale (zero it out)
Start the timer and begin adding water (approx 200ºF) until it reaches 284 gr
Stir the water/grounds slurry for 3-5 seconds
Steep water/grounds slurry for another 45-60 seconds
Remove the mug+AeroPress from the scale
Finish the brew by plunging out the contents of AeroPress into the cup
Enjoy

Total brew time with pouring, stirring, steeping, & plunging: ~90 seconds.

Note: Some AeroPress nerds will howl at this and suggest other/better brewing methods, and that's fine. Go to YouTube for those instructional videos. This post is about the scale. :)

People who are coming from electric brewing methods or pods machines often see me going to all this work to make a single cup of coffee and scoff. I get it. It takes time and effort.

But here's the thing: Like most work, practice makes perfect. And the "new" work eventually becomes second nature/muscle memory. So after 5+ years of brewing this way on various devices (AeroPress, Chemex, Kalita Wave, etc.) - I hardly even think about it anymore.

So if you care about making a great cup of coffee and are willing to work a bit at it at first, you'll eventually become a killer cup-brewing machine and not have to fuss too much about it.

And you'll also be able to take this ratio to any number of other brewing devices and methods. Keep in mind that the 1:17 ratio is specifically for drip coffee. Other devices/methods use other ratios. Espresso is usually about 1:2. Cold brew concentrate is about 1:3.

So there you have it: The Why & How of using a scale for brewing coffee. Enjoy your knowledge upgrade, coffee lovers!