I’ve been using scales for brewing coffee for years. My friend who owns a bakery first clued me into this way of controlling not only the amount of grounds, but also the amount of water that go into a particular brew.
At first glance, it would seem like measuring water with a scale is overkill: it’s easy to measure water with a cup measure. However, when brewing drip/pour-over with fresh coffee, the bloom of the coffee prevents you from being able to accurately measure the water going into the brewing vessel. Same deal with espresso: the crema in your shot expands the volume so that you can’t measure it effectively. So, scales to the rescue: they precisely measure the amount of water regardless of bloom or crema.
For pour-over or french press, I’m typically brewing for just myself. For a French Press, I measure out 14g of beans and then put a scale underneath the press. I then pour in 210g of water. How did I arrive at these numbers? I started with how much coffee I like to drink in the morning: about 7-ish ounces. I then used a 15:1 brewing ratio of water to grounds and converted it all to grams. This concept of a brewing ratio is a useful one: you can use it to find what ratios you enjoy, and then scale up or down the amount of coffee you like to drink.
For espresso, I’m even a bit more obsessive than most with scales. I use them at the grinding and brewing end. For my grinder, I measure out a bit more than 18g of beans, and then after I grind it, I tare it down to 18g precisely. Why take this extra step? It’s because of my grinder: despite my best efforts, some grinds tend to get trapped, and so the amount that comes out varies a decent bit.
Then, when brewing, I put a scale underneath the cup I’m pulling the shot into, and measure the amount of espresso in the shot, which is 1.5 oz. This isn’t the usual approach: I’ve seen many coffee shops that do a very good job pull shots into a measured shot glass and measure the shot by volume. While this is a pretty good approach, it’s inaccurate because of the crema expanding the shot and making it difficult to measure. Also, it means that you have to pour the espresso from that shot glass into the drinking cup, and in that process some of the precious crema is left behind in the shot glass. Popping a scale underneath the cup, and pulling the shot right into the cup gives you both precision and collects every morsel of crema.
Is this obsession with precise measurement really necessary? That depends. For me, the precise control of the brewing process provides solid platform that greatly increases my enjoyment of quality coffee.
Here’s how I think of it: accurate brewing measurements create a technical foundation for the artistic and culinary aspects of quality coffee. Given that solid foundation, it’s fun to explore the possibilities of different coffees and go exploring for different tastes.