How to Make Coffee the Scientific Way?
Even though it is a poor barista who blames his tools, the fact is that toys like Bluetooth-enabled scales and refractometers can give you an even deeper understanding of the world of coffee.
The most important piece of barista equipment is a high-quality scale. It’s hard to make good coffee without knowing the exact weight of the coffee. There are any number of brewing scales with built-in timer on the market, with prices ranging from low double digits to low triple digits.
The higher-end scales, such as the Acaia Pearl, beat out the less expensive competition especially when it comes to sensitivity and rapid responses to changes in weight.
“The Acaia has a sensitivity of 0.1 grams and it responds to changes in weight in 20 milliseconds, which is superfast. With ordinary scales, there’s always the wait to see what the final reading will be,” says Karoliina Mäkelä, Training Expert at the Paulig Barista Institute.
The Acaia is also Bluetooth-enabled, which means that it can connect to a Brewmaster app on your phone or tablet. The app lets you keep a personal coffee journal and also compare and share brew experiences with fellow coffee enthusiasts.
“When you put the coffee dose in a filter placed on the scale, the app will calculate the necessary amount of water and brewing time at the extraction ratio chosen by the barista. The app also displays the brewing process in real time and at the end of the process, it generates a graph depicting the amount of brewing water as well as the speed, intensity and timing of the pour. This is a huge asset for recipe development and learning.”
Refractometer measures TDS in coffee
Baristas looking to really delve into the process of manual brewing will need a refractometer, which is a pocket-sized tool that optically measures the TDS (total dissolved solids) percentage from just a few drops of coffee. The TDS figure tells you the amount of coffee grounds that have dissolved into your coffee.
When you have not only the TDS figure but also the extraction ratio of the coffee, that is the amount of coffee grounds and water, there is a handy VST Coffee Tools app available for your phone that lets you determine the percentage extraction.
“A high TDS will tell you that either the coffee dose was too high or the coffee was too finely ground. A high percentage extraction indicates that the brewing time was too long, the water temperature was too high or there was excessive turbulence during the brewing process.”
The brewing process is influenced by any number of factors, including brewing method, extraction ratio, brewing time, water temperature and motion, and the coffee used and how finely it is ground.
Water optimization alternatives
“You don’t need any equipment at all at home to be passionate about coffee. Then again, there are those whose kitchen features every tool in the box, starting with their home roaster,” Mäkelä says.
If you want to go full-out geek, you will first filter the water to remove all dissolved substances and then optimize the remaining H20 with water optimization capsules that contain the optimal amount of minerals for coffee brewing.
“The substances that have dissolved in the water make a huge difference to the coffee. Carbonates – magnesium and calcium – are the most vital to coffee-making, along with pH value. You can immediately tell from the flavor of the coffee if there is something missing from the water, or too much of something.”
Even if water optimization seems a bit too far-out geeky, Mäkelä nonetheless recommends that every barista have the water at their workplace or home analyzed so that they can filter out unwanted tastes or odors.
”All water is different. Having your water analyzed can give you insight into flavor issues. For example, if the acidity of a given coffee does not come through as it should, this may be due to a lack of magnesium in the water.”