 |
| Have you ever wondered why your coffee brews aren’t as good as those served to you at your local coffee shop? Or, do you find it frustrating to dial-in your coffee every time there’s a small change? This is a common source of frustration for many – and if left unchecked, can undermine one's willingness to explore and enjoy the landscape of great coffees. |
If this has been your experience, this article may help you resolve these frustrations and expand your ability to produce consistently great brews each and every time.
But first let’s start with what is one of biggest sources of problems with brewed coffee – which is measuring coffee grounds by volume via coffee dosing scoops. While this is indeed be the most common method for measuring grounds, it is also very imprecise.
Historically, these dosing spoons were provided with ground coffee and coffee makers, each calibrated to a particular roast level, grind, and serving size (hence the variety of shapes and sizes). But with coffees now available at any desired roast level (very light to very dark) and the ability to adjust grind settings, dosing spoons are no longer a very reliable tool for measuring coffee.
To illustrate why dosing spoons are problematic, let’s compare two small samples of light and dark roasted coffees (see below). Both of the samples depicted are the amount necessary to brew just a single serving of coffee.
Notice that the sample on the right requires a greater number and larger volume of beans to dose a single serving as compared to the sample on the left. Why is this the case? Well, when coffee is roasted, it releases both CO2 and moisture, resulting in a loss of bean density – and weight. So dark roasted beans weigh less than light roasted beans. In this case, if we were to measure by volume, it would require more "scoops” of the dark roasted grounds to get to the same strength of coffee as the light roasted beans. This discrepancy multiplies the error as the number of servings increase.
So, if volumetric measurements (dosing spoons) are inherently unreliable, how should we measure? The answer is: by weight. It’s simple, inherently reliable (no matter the coffee, brew method, and grind), and it’s the only way we have found to dose coffee consistently. For those of you not accustomed to dosing coffee by weight, the prospect may at first seem burdensome, but the approach that we will outline is simple to use and easy to remember. What’s more, it takes away all of the guesswork, it provides a solid foundation for consistently dialing-in your preferences, and it opens the door to informed experimentation.
Selecting a scale for brewing coffee
Note of Affiliate linking: Affiliate Links (*) Some links on this page are affiliate links which means that, if you chooser to make a purchase through those link, SteffenMarkkus may earn a small commission at no extra cost to you. Each affiliate link is indicated below with an asterisk.
Now that you have an understanding of why volume isn’t a reliable method for measuring coffee grounds, let’s discuss how to dose by weight. Before getting ahead of ourselves, let’s discuss the tools we need for measuring coffee.
You can use a kitchen scale, a jewelry scale, or a scale designed for coffee brewing – so long as they can measure weight in .1 gram increments, almost any scale will do. Here are three scales I use for dosing and brewing coffee on a daily basis:
*American Weigh Scales (AWS) Blade Pocket Scale (Amazon.com):
 |
This is a very inexpensive scale (< $20) and is very convenient to use for weighing beans and grounds. The “blade” on the side slides closed when not in use, and the scale includes a case for transport/storage. It has a quick response time to changes and has a range from .1g to 1kg (2.2 lb). However, it is not water-proof, so you have to be a careful not to spill water onto it. |
*Hario V60 Drip scale (Amazon.com):
 |
This is a reasonably priced coffee dosing and brewing scale ($50-60) with .1g resolution and a capacity up to 2 kg (4.4 lb). Just like the AWS scale, it’s very convenient to use for weighing beans and grounds. It is very responsive and can measure both weight and brew time simultaneously, making it a great companion for performing timed brews. It is designed for brewing pour-overs and has a large platform to accommodate brew-pots. |
Acaia Lunar scale (Acaia.com):
 |
Acaia scales are precision commercial coffee scales designed for both dosing grounds and brewing coffee. Like the Hario V60, they can measure brew times, but can also measure flow rates (for espresso pulls). Additionally, they have configurable event timers, are rechargeable and have mobile apps to do post brew data analysis. Acaia scales start at $150 (for the larger Acaia Pearl). The Lunar is a more compact version of the Pearl, and is intended for use with espresso machines. It is priced at $250. |
Dosing coffee using a scale
Okay, now that we’ve discussed the importance of using a scales and what types of scales are suitable for measuring coffee, let’s get down to the brass tacks. Although we could get very precise on dosing for every type of brew (and may do so in the future), we’re going to keep things broad to cover multiple types of brews. We will, however, point out some differences for moka pots and espresso.
Dosing for automatic coffee makers
If you are using an automatic coffee maker, the standard serving size for most automatic coffee makers in the USA is 5 fluid ounces, or just under 150 milliliters (ml). Now, you may want to verify the serving size of your coffee maker before proceeding –noting the actual serving size in if it differs significantly from the 5 fluid ounce standard. Dosing for most automatics is very easy to remember and calculate in your head:
Amount of Ground Coffee = 2g coffee / 1 fluid ounce water brew water
Or 10g coffee / serving (5 fluid ounce servings)
*OXO 8-Cup Automatic Brewer (Amazon.com) with 150m/5oz fill lines
So, for two servings, the amount of grounds you need would be 20 grams, for 3 servings 30 grams, and so on. If your brewer serving size is 6 fluid ounces per serving, then the amount of coffee you would be 12 grams per serving, and for 8 fluid ounce servings, 16 grams per serving.
Now, this is a starting point. Adjust the total amount up/down in 1 gram increments to fine-tune your strength preferences.
Dosing for coffee makers without fill Lines and pour-overs
Coffee Makers without fill lines can be challenging, but we have an easy method for handling these as well. Recall that we said that 5 fluid ounces is approximately equal to 150 ml? Well, it turns out that water measured in milliliters is same number in grams; that is, 1ml of water is equal to 1g of water. So, 150ml of water is 150g of water. Knowing this means that we can then dispense the water with the brewer on the scale and know the volume of water from the weight. The dosing formula is the same, i.e., 10 grams per serving or 10g/150ml. From this we know that two servings is 300ml, four servings is 600ml and so on. Next, we measure out our coffee grounds, and place them into the brewer, then place the brewer onto the scale and zero it out to in preparation for measuring the weight ( and volume) of water.
Amount of Ground Coffee = 10g coffee/150ml brew water
Or 10g coffee/150g brew water
Again, this is the starting point for calibrating your individual strength preferences, adjust the amount of coffee grounds up and down in 1g increments to determine your own strength preferences.
Special cases:
Moka Pot (sometimes called a caffettiera or Bialetti)
Bialetti moka pots come in 8 different sizes. If you don’t know the size of your particular moka pot, simply fill the lower chamber to the line just below the pressure valve. Then measure the volume of the water in ml. The amount of coffee grounds needed for this type of brewer is 10 grams per 100ml water. So, simply divide the total capacity of the lower chamber by 10 to determine the amount of grams of coffee. So, if you have a 130ml moka pot, the amount of ground coffee you need is 13g. Adjust the grind setting so that the dosage fits into the filter basket without compacting. Then fill the lower chamber to the fill line with water and brew.
*Bialetti Moka Pot (Amazon Affiliate)
Espresso
For most espresso machines, portafilter baskets are 58mm in diameter with capacity to handle anywhere from 14-22g doses of coffee grounds. Check with your espresso machine’s specifications to determine the capacity of the portafilter basket (this determines output), then measure out the coffee in grams prior, fill the portafilter basket, and compress the dose according to your espresso machine's recommendations. There are three strengths of output you can brew:
Ristretto: liquid output in grams = input dose size in grams, with a brew time of 10-15 seconds. Adjust your grind to fit to extract coffee within the target brew-time window.
Espresso: liquid output in grams = input dose x 2 in grams (double), with a target brew-time of 20-25 seconds.
Lungo: liquid output in grams = input dose x 3 in grams (triple), in 35-40 seconds
So, if we have an 18 gram dosing basket, you would brew 18 grams (ml) for a ristretto, 36 grams(ml) for an espresso, and a 54 gram(ml) for a lungo. For espresso shots, adjust grind setting to extract liquid output within the times listed as a starting point, then and adjust grind/extraction times to taste. The lighter the roast, the finer the grind.
Fine-tuning the flavors in your brew
Now that you’ve figured out the coffee strength part of the equation, you then use grind settings to balance the flavor of your brew. Coffee naturally exhibits bitter flavors, but can also extract sweet and sour flavors. As we demonstrated previously, lighter roast coffees are denser. As such, they require more contact with water than dark roasts to extract flavor; and, the way we to adjust the amount of water contact is through grind settings. Finer grind settings increase the surface area of the grounds, which also increases the contact between the grounds and water. Coarser grinds do the opposite. Of course, grinding too fine can result in astringent or very bitter tasting coffee (referred to as over-extracted). At the other extreme, too coarse of a grind may produce weak tasting or sour flavored coffee (referred to as under-extracted). So, grind finer to reduce sour flavors and grind coarser to reduce bitterness.
Discerning the difference between sour and bitter
Now sour and bitter are easily mistaken for each other, which can lead you astray. Sour and bitter are on opposite ends of the spectrum – with sweet and savory in between. Sour flavors will often remind you of fruit flavors such as lemon or lime (though you may not taste those flavors, the feeling is the same). Taken to the extreme, sour may be very sharp and acidic (like unsweetened lemonade). At the other end of the spectrum, bitter flavors may leave an aftertaste reminiscent of walnuts or beer (hops). Extreme bitter flavors are often astringent (dry mouth, like trying to eat a green banana).
The best way for you to calibrate the flavors in your mind in the context of coffee is to take a very light roasted coffee and taste the difference between three brews, one with a coarse grind setting, a second with a fine grind setting, and a third that is midway between the two (same dosage for each brew).