Here’s a question I’m asked quite often by home coffee brewers – how much friggin coffee should I be using? The mystifying coffee-to-water conundrum trips up a lot of people, but there’s a straightforward way to make sure you’re using the correct dose for any size batch and any brewing style, and right now I’m going to reveal a little secret that’s kept professional baristas on point for ages. (As I type this I’m imagining myself as the masked magician from Breaking the Magician’s Code – do you remember that show?)

First, take your coffee scoop and throw it in the trash where it belongs. Do you have a kitchen scale? Great! You can bake our awesome scone recipe! A trusty scale will do wonders around the kitchen, and is an essential tool in your coffee brewing arsenal. Here’s my quick soap box: since coffee brewing is a delicate balance of variables, we need the basic ability to measure those variables so we can modify, and repeat, our results. The coffee-to-water ratio is a fundamental variable in brewing, and repeating, a delicious cup of coffee.

Coffee by Weight + Water by Volume = Delicious Brew

Coffee by weight is the dose of coffee that you’ll use. Use too much coffee, and the resulting flavor will be underdeveloped. Water by volume is the amount of brewing water you’ll need. Too much water (or, not enough coffee) will lead to over-extraction and bitter, harsh flavors. (And remember, your water volume is your brewing water rather than the amount of resulting coffee beverage you want to drink. Some of this water will be retained in the brew bed.)

The recommended standard for all brewing methods – including manual or automatic – is a ratio between 1:15 and 1:18. This means that for 1 gram of coffee, you’ll need between 15 to 18 milliliters of water (grams and milliliters are used interchangeably since they are 1:1). But 15 ml sounds like the world’s tiniest cup of joe! Just scale up the ratio to fit your needs. Want to use 20 grams of coffee? Cool, then multiply that number by 15 (it’s 300) and that’s how much water you should use. Want to brew with 825 ml of water? Not a problem, simply divide that by 15 (which is 55) and use that much coffee. Got it? Good!

(And if you’re super resistant to metric and just reeeaaallly need to think in ounces, consider that 1 oz is roughly 30 ml. )

That’s all well and good, but how do you know you’ve landed on the right ratio for you? Here’s what to taste for to see if your ratio should be adjusted. Does the coffee taste weak or underdeveloped? Then you need to use less coffee or more water. Is it bitter and harsh? Then you need more coffee or less water.

Get the Tools You Need

Your basic kitchen scale should be enough to set you on the path to better coffee. At Mammoth Espresso, we also sell a wonderful scale by American Weigh that’s perfect for home or travel and measures to the tenth of a gram. It’s also budget friendly at around $30. On the high end, we also use two scales made by Acaia (the Lunar and the Pearl). These are excellent and hold up well against dings, drops and spills, but they come at a much higher price. You can find Acaia through many online retailers.

Have a coffee question? Drop me a line at info@mammothespresso.com.