In his book, The Blue Bottle Craft of Coffee, Blue Bottle founder and CPO James Freeman lists the two indispensable tools for better pour over coffee: the gram scale and the swan-neck kettle. When it comes to precision, it’s pretty easy to understand why the former is so important; understanding what the latter has to do with it, however, might be a little less intuitive. Writes James:
“Using a swan-necked kettle will help the accuracy of your pour and, hence, improve the consistency of your extraction. Some people might rebel at paying $50 for a kettle, but how many people have paid for a pizza stone they never use or an ice cream maker that lives in the back of a kitchen cabinet? If you buy a gram scale and a kettle, you’ll use them every day, and you’ll drink better coffee almost immediately.”
Of course, any kettle will do in a make-it-work moment, points out Mallory Leicht, a Trainer at Blue Bottle’s Webster cafe. “But the ideal kettle for brewing pour over methods,” she goes on, “is one with an elegant, swan-shaped spout.”
This design is what makes the swan-neck kettle ideal for optimal coffee extraction. “In contrast to a wide-spout kettle, the thin s-shaped curve of the spout mimics the neck of a swan,” says Mallory. “This shape allows you to precisely control the flow rate of water as it leaves the kettle and pours onto the coffee. As you pour, water gently glides out in a much more measured and controlled flow rate.”
Why Is Pour Rate So Important?
Pour rate is a major variable in coffee extraction. Extraction is the concept that comes into play when we talk about the flavors taken out of the coffee by water during the brewing process.
“Consistent and controlled flow rate helps your coffee to extract more evenly during brewing, resulting in cups with better clarity and balance of flavors,” says Mallory. “That’s why it’s so important when you’re making pour over. If you pour too heavily, you can pull too much flavor, overextracting through the turbulence of the water. You surpass the sweet spot and take it to bitterness.”
This idea goes the other way, as well: Pour too slowly, and you risk underextraction and a sour taste. “The intentional and consistent turbulence of controlled flow rate is how you hit that sweet spot,” says Mallory. “Our general rule is 100 grams per ten seconds—a pretty calibrated flow rate."
By controlling pour rate, Blue Bottle baristas can keep turbulence, and the agitation it causes, as a set variable in the making of delicious coffee.
While baristas may control for other variables like agitation, as James writes in Craft of Coffee, these should still be kept in mind, especially by beginners. Another variable to consider is grind. “A finer grind will extract more slowly,” James says, “regardless of the rate at which you pour.”
For this reason, mastering the perfect pour rate with your swan-neck kettle isn't the end-all to delicious pour over. “Even if you have a consistent flow rate,” says Mallory, “if you don’t have the right grind, your extraction will be off.”
The Ergonomics of Pour Over
Balancing these variables is one reason why Mallory became enamored with coffee at her first barista job in Springfield, Missouri. "I started in the industry back in college, and got hooked by the attention to detail," she says. "There was just so much to learn. And being part of a smaller coffee community, I was hungry to learn more from larger communities, which is why I became a sensory judge in regional and national barista championships."
Having been a barista as well as a trainer, Mallory has learned all too well that perfecting technique goes further than a delicious cup of coffee. For baristas, who spend hours at a time using their swan-neck kettles, posture is yet another variable to bear in mind. "Having an ergonomic pour over style is important," says Mallory. "Better distributing your weight keeps you from hurting your wrists in the long term. It also gives you more control over your pour."
Swan-Neck Kettle Tips
- Elbows In: Tuck your elbow close to your side as you pour, rather than holding your arm and shoulder out at a wide angle. You might notice an instant ease on your shoulder and arm, because tucking your elbow in enhances body ergonomics by shifting the weight of the kettle and more evenly distributing it over the brew. This is better for your body and better for the brew.
- Always Pour Clockwise: According to the Ueshima Coffee Co. Academy in Japan, writes James, the right pouring direction is "always clockwise." Still, "In your own kitchen, this rule is flexible."
- Check In with Your Body: Your biggest consideration should be comfort. "When you're pouring correctly, your weight should be distributed evenly," says Mallory. If you aren't comfortable, it's possible your technique could use some work.
- Water Levels: Be mindful of the amount of water in your kettle, as it will affect your pour rate.
- Small Changes, Big Results: A simple change in technique can affect flavor, even with all other variables remaining the same. Keep this in mind
- What About My Free Hand?: "Many baristas hold their free hand behind their back. What I like to do is put a towel under the kettle and hold it with my left hand as support. This gives me better balance and a clean flow rate. With my elbow tucked, I have even more control."
Technique Meets Aesthetics
As with any other brewing method, practice makes the path to perfection. “Don’t be frustrated if you can’t pour slowly and steadily right away," writes James. "It’s a skill. Just keep practicing.”
"Practicing is how you build that attention to detail and those muscle memories so you can pour like a Blue Bottle barista does," says Mallory. When your posture and technique are in place, you get the barista-grade coffee, too. “The beauty of the kettle,” says Mallory, “is just a bonus.”
Learn more about another tool for making better pour over: Blue Bottle's custom Dripper.
Follow Mallory on Instagram.