How to use the app
The app has three calculators built in: the original Cowculator, a Cup Size Calculator, and the ‘Reverse Cowculator’. You can switch between calculators by clicking on the title at the top.
The original Cowculator gives you the breakdown of coffee, fat, protein and sugar in your milk drinks. For a full discussion of these components, take a look at the OG cowculator blog post.
The Cup Size Calculator
This calculator is useful if you’re setting up a new cafe, or deciding what size cups to buy for your barista competition. If you start with a fixed espresso recipe, and input what strength you want your final milk drink to be, then the calculator can tell you what size cup you should use.
Put in the size of your espresso and the expected TDS, pick values for condensation and aeration (or stick to the defaults), and then decide how strong you want your drink to be. A typical cappuccino might be 1.4%, similar to a filter coffee. A flat white would often be stronger, perhaps around 2%. Click on ‘calculate’ and the app will give you an estimate of how much milk to put in your jug, and what size of cup you would need to make that drink.
The Reverse Cowculator
The last calculator is for the rare occasion when you have a cup already, and need to pick an espresso recipe to work with it. This might help you if you’re deciding what filter baskets to buy, or how many shots you need to add to a Venti latte to be able to taste the coffee.
Put in the expected TDS of your espresso, and the target strength of your drink. Again, a cappuccino might be around 1.4%, while a flat white would often be closer to 2%. Enter values for condensation and aeration (or stick to the defaults), put in your cup size, and click ‘calculate’. The app will tell you how much espresso you would need to reach that strength in the cup, and you can design your espresso recipe accordingly.
For example, if I have a 6oz cup and decide I want to make a flat white at 2% strength, and my espresso is normally around 8% TDS, the app tells you that you need 36g of espresso.
Condensation and Aeration
Most of the terms in the app should be familiar to any barista, but these two might trip some people up. Condensation is the amount of water, from the steam, that condenses into the milk. The amount of water added ranges from 5-10%, depending on your machine — but if you don’t want to measure it, stick to the default value of 7.5%.
Aeration refers to the total increase in volume of the milk. This includes the foam, but also includes the extra water added by condensation — so the amount of aeration cannot be lower than the amount of condensation. We recommend aiming for an aeration level of 33%, but you can also adjust this figure if you like foamy cappuccinos or very flat flat whites.