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Updated for 2021. Today we’re taking you through how to get the right grind size so that you can get a good espresso. Getting the correct grind size is critical when making espresso, so what’s the process called when finding the right size? That’s called dialing in. We’ve got a lot of information about dialing in grind size and how to make better espresso, so keep reading.
To dial in your grind size, you have to time how long it takes to pull a given liquid volume and make adjustments to the grind size. Your goal is to produce a double shot in 20-30 seconds, from the first drip from portafilter spouts.
Now let’s get into exactly how this works.
Before you start, make sure the machine is fully warmed up with the portafilter locked in place. Depending on the machine, warm-up can rake anywhere from 10-30 minutes, while that’s heating grab your favorite fresh whole bean coffee. Any coffee can be used to make espresso if you’re new and learning, but we recommend using a coffee that’s known to make a good cream-rich espresso. Here are some popular options:
All three coffees are very easy to work with, they’re Italian-style bean blends which produce crema-rich shots when the grind is right. Lavazza and Maromas were both roasted in Italy and when stored properly they hold up really well. Coffee MIO is a 100% Arabica blend that’s grown organically, roasted in Australia and then air shipped to us on a regular basis so it’s very fresh.
The key to making good espresso is the control of variables. As you pull a number of shots and dial into the right grind size, all other variables should be the same. Grind size adjustment is the only variable that should affect the extraction. So when dialing in, be consistent with the other main variables including dosing weight, tamp and brew temperature.
For the initial grind size, adjust the grinder to produce a particle that looks and feels like it’s finer than granulated sugar. Make adjustments and repeat as needed to get the consistency right. Depending on your grinder, there may be some retention so as you make adjustments run the grinder for a few seconds to flush out the old grinds before judging the new grind size.
For the weight of your coffee dose, we recommend using 16-18 grams. This is the typical dose range for a double espresso.
Now if you don’t have a scale, no problem. If you overfill the portafilter a bit you can level the ground coffee using your fingers. Make sure to not press down, just gently wipe off excess ground coffee so it’s level to the top of the filter basket.
From there, use a quality tamper to compress the ground coffee in the filter basket. The most important thing when tamping is to produce a smooth and level surface. Actual tamping pressure is not critical, what is critical is using a similar pressure each time you tamp so that you’re as consistent as possible.
A good tamper is the Espro Calibrated Tamper, which gives a little when tamping so it’s easy to maintain consistency. If you don’t want to worry about consistent tamping pressure, try out Asso’s Jack Leveler. They come in a variety of styles and level off and tamp the coffee for you.
After tamping, look at the surface, if it’s lower on one size then it’s uneven. This uneven depth can cause channeling and throw off the timing of an extraction. Discard the coffee grounds and try again.
Note: Before attaching the portafilter and pulling the shot, you may need to flush your brew water if you’re using a single and heat exchange boiler machine.
With the portafilter loaded and the machine ready, pull your shot. Pay attention to the timing so it’s no more than 30 seconds. We used Rattleware’s 3 oz shot glass pitcher to measure the shot and used a stopwatch on our phone to time it.
Now, it’s not unusual when dialing in the grind size for it to take a few tries. So to help you overcome some speed bumps, here are a few tips to keep in mind:
Use the same coffee dose weight and tamping pressure for each shot when dialing in. It takes some judgment to determine what adjustments are needed so be aware.
As beans age or if you change the coffee you’re using, you will likely need to tweak your grind size a bit—a grind setting that works for one coffee doesn’t work for another and that’s okay. Every coffee has different characteristics and needs before extracting espresso. Play around with the grind size until you find the sweet spot.
When we refer to the “coffee-to-water ratio”, we’re talking about the golden rule of espresso. This means making sure that all of your variables as stated above fall within the proper range so that you’re extracting a 2-2.5 oz shot of espresso within 20 - 30 seconds. This will ensure that you’re getting all of the delicious flavors and aromas out of your coffee and that it’s the perfect consistency if you decide to turn your double espresso into a creamy cappuccino.
We hope you take all of this information and play around with your coffee bar set up to find that sweet spot. Remember, consistency is key when getting a good cup of espresso and dialing in your grind size is one of the most important factors to achieve that.