Brewing Coffee by the Numbers

October 13, 2005

coffee spoons
One common mistake in brewing coffee is to not use enough ground coffee. This is no real surprise, as often coffee brewers and even coffee packaging itself has incorrect or misleading advice.

When we brew coffee, we want to extract roughly the “first two-thirds” of the flavor of the bean — that’s where all of the “good flavor” is. The “last third” is where all of the bitterness and nasty flavors lie, and we’d prefer to just leave that right in the grounds, instead of in our cup.

Unfortunately, when you “underdose” the amount of coffee, you “overextract” and end up with a nasty, bitter cup of coffee. Some people mistake this bitterness for “overly strong” coffee, and dose even less to try to get rid of it — making a weaker but even more bitter brew.

The standard measure is to use 10.6 grams (.38 ounces) of coffee per 6 oz. (177 cc) of water. While weighing our coffee on a gram scale would probably be a great idea (since bean density varies with variety, roast and humidity), most of us aren’t going to bother.

Fortunately, using a rough approximation of 2 tablespoons per 6 oz. of water is “close enough”.

Remember that coffee makers vary on what they consider a cup (usually between 4.5 oz and 6 oz — never 8 oz), so be sure how much water you’re really brewing with in your 8 or 10 cup coffee maker (you only have to measure it once).

Some handy approximations — 1 cup is about right for most “8 cup” brewers, and 1 1/4 cups is likewise for most “10 cup” brewers.

If you want to get more exact, or the math is bogging you down, you can always use this handy Brewing Ratio Chart from Black Bear Coffee.