Breaking a Bad Habit
Just like you, I know lots of people who spend time thinking about how they can help the contemporary coffee scene move forward. And being a tech head, the ideas I have for this tend to be techie ones. Although it isn’t the first time, I want to advance (again) a technique that I believe will eventually help us all make better espresso.
It’s so simple, it sounds trivial or even silly:
When you talk to others about how you make your espresso, specify the “volume” of your shot in units of mass (grams) rather than units of volume (ounces or milliliters).
Of course you are asking, what difference will THAT make?
Well, most people would agree that the last ten years have seen tremendous progress in espresso quality. The shots pulled at recent barista competitions are far better than those pulled ten years ago. This is due to hard work by farmers, greens buyers, roasters, baristas, and machine designers, but it’s also due to the ease with which those same people can share experiences with their colleagues. Exchanging tips and techniques via web, email, video, etc. has revolutionized the way we teach each other to make espresso.
Every barista knows that a crucial part of how we make an espresso is the shot “volume”: how “ristretto” or how “lungo” it is. And reporting how many GRAMS of espresso we extract is FAR more useful than reporting in ounces or milliliters.
- Espresso volume is a moving target. Day by day, as beans age, the volume of crema they produce decreases. This can make a 20% difference in measured volume.
- Spouted portafilters collapse crema as espresso runs through them. A spouted shot will measure 10-15% lower in volume than the identical shot through a bottomless portafilter.
- The calibrated shot glasses that many folks use to measure volume are not precision measuring devices. Many of them are off by 5% or more.
- As crema dissipates, espresso volume decreases. If you hesitate even a few seconds before measuring, the volume has changed.
- A shot that runs a few seconds longer than usual will measure lower in volume simply because the crema bubbles are bursting in the cup as the extraction proceeds.
Add these factors up randomly and one person’s “1.5 ounce shot” can be vastly different from someone else’s.
In contrast, espresso shots measured in grams weigh the same whether there is lots of crema or little; whether pulled through bottomless or spouted; whether weighed immediately or a minute later. And even a cheap $20 gram scale is more accurate at measuring weight than our shot glasses are at measuring volume.
Aside from the pure accuracy of using grams rather than ounces/millimeters for espresso volume, there are other benefits:
- You begin to think of “ristretto,” “normale” and “lungo” shots as ratios between grams of dry coffee dosed and grams of beverage extracted. The confusion that results from the haphazard use of these terms suddenly vanishes.
- Measuring the amount of espresso beverage in grams is an essential first step in calculating extraction yields with ExtractMojo or MojoToGo. I am confident that this technology will have a huge impact on our industry.
Unfortunately, our bad habit of measuring espresso in ounces/milliliters seems to be a very hard one to break. So far it is too radical a concept for most coffee companies: Intelligentsia, Counter Culture, 49th Parallel and Stumptown post instructions for using their espresso coffees, but sadly, they measure extracted volume in ounces.
Make no mistake, I have big respect for these great companies, but since they trust us enough to specify the coffee dose in grams, why do they assume we’re too lazy to measure the amount of espresso in grams? These companies could help move things along by taking a tip from the prodigious and open-minded James Hoffmann: as a compromise, try using ounces or milliliters AND grams for the amount of espresso extracted. Here is a recent Square Mile brew recipe for one of their espressos:
Brew Temperature: 200°F/93.5°C
Brew Time: 25-28s
Total Volume: approx. 50ml
Brew Ratio: 60% – approx 30-35g of liquid
James, you are awesome!