Espresso · Milk
Cappuccino: a third, a third, a third
A cappuccino is the foamy member of the espresso and milk family.
- Coffee
- 18 g
- Cup
- 180 ml
- Temp
- 93 °C
- Time
- 1:30
In CupTune's build the cup holds roughly one part espresso, one part milk and one part foam, so the drink is small, thick on top and noticeably coffee-forward next to a latte. This page is about getting that foam: how long to let air in, how to know when you have enough, and what to do when it comes out wrong. It assumes a machine with a steam wand. For the milk-heavy version, see the latte recipe.
The spec
| Part | Amount |
|---|---|
| Espresso dose | 18 g |
| Espresso yield | 36 g (1:2 beverage ratio) |
| Liquid milk | 72 ml |
| Foam | 72 ml |
| Liquid in the cup | 180 ml |
| Cup | 240 ml tulip cup, so the drink fills 75 % of it |
| Cold milk to start with | about 120 ml |
| Milk temperature | 50 to 60 °C when you stop steaming |
| Total time | 90 seconds |
The drink is 36 ml of espresso, 72 ml of milk and 72 ml of foam, 180 ml in a 240 ml cup. Foam keeps rising for a moment after the pour, so the empty quarter of the cup matters.
You need
- An espresso machine with a steam wand, and a grinder.
- A scale that reads to 0.1 g.
- A small milk pitcher, 350 ml or smaller. A big one makes 120 ml of milk hard to steam.
- A thermometer.
- A 240 ml cup.
- Fresh cold whole or semi-skimmed milk, straight from the fridge.
Ratio 1:2 · Grind: Espresso · grind chart
Starting ranges come from your grinder maker’s own guide. Burrs, beans and calibration vary, so treat them as where to begin.
Steps
- 0:00, Pull 18 g into 36 g.
Dose 18 g, aim for 36 g. Start the timer when you press the button.
- 0:30, Stretch 12 s, tip at the surface.
Purge the wand. Hold the tip just under the surface and keep it there for about 12 seconds. You want a steady, quiet tearing sound. The pitcher should feel barely warm and the milk should rise visibly.
- 0:42, Texture to about 60 °C, wipe wand.
Sink the tip and spin the milk. Stop at about 60 °C. Wipe and purge the wand.
- 0:58, Tap and swirl until glossy.
Tap the pitcher to pop the largest bubbles. Swirl until the surface is smooth, thick and shiny, like wet paint.
- 1:06, Pour milk, then top with foam.
Pour the liquid milk first into the shot, then spoon or ease out the foam. Aim for about 72 ml of each. The foam should stand above the rim of the milk.
My notes for this recipe
Why the foam gets its own paragraph
The numbers say 72 ml of foam against 72 ml of liquid milk. Real foam is not separate from the milk: it is the same milk with air in it. So the target is one pitcher of milk that ends up half liquid and half foam, and that is why the build starts from about 120 ml of cold milk. Steaming adds air and some water as steam condenses, so 120 ml becomes about 144 ml, the 72 plus 72 the build asks for. The 20 % growth figure is an authored estimate. Measure the milk in your pitcher before and after on your own machine and adjust the starting volume until the pour matches.
Take a cup 8.5 cm across, which has a top area of roughly 57 cm². Spread 72 ml over that and the foam layer is about 1.3 cm deep. That is arithmetic, not a measurement, and your foam will settle as you drink.
Why these numbers
One third each. The builder's own note calls it "roughly a third espresso, a third milk and a third foam". CupTune treats that as a common description of the drink, not a rule. No standards body fixes it and cafes size cappuccinos from about 150 ml to well over 200 ml.
18 g in, 36 g out. The 1:2 ratio is the average that surveyed baristas reported in the SCA's espresso article. The 18 g is an authored starting point.
Twelve seconds of air. Authored. A latte takes about six. Doubling the air time is the main difference in technique, and the amount depends on your wand.
50 to 60 °C. Klimanova et al. (2022) steam-frothed milk across 30 to 80 °C and report an optimal final temperature of 50 to 60 °C for microfoam. That is a finding about foam, not about what you like to drink, and it came from one lab study of two milk types. Foam is what suffers when you overheat, so stop earlier rather than later.
If it looks or tastes wrong
- Foam is stiff and dry like shaving foam. Too much air, or the milk sat before pouring. Cut the stretch to 9 seconds and pour at once.
- Barely any foam, drink looks like a latte. The tip went under the surface too soon. Keep it at the surface until the pitcher is warm to the hand.
- Foam collapses within a minute. Old milk, a greasy pitcher or too hot. Rinse the pitcher with cold water, use fresh milk and stop at 60 °C.
- You cannot taste coffee. Shorten the cup or lengthen the yield to 40 g. See the dial-in guide for changing one variable at a time.
Each fix here is a CupTune judgement call, not a measured result.
Evidence and limits
Two numbers have a published source: the 1:2 ratio and the 50 to 60 °C foam temperature. The thirds proportion, the 120 ml starting volume, the 20 % expansion and the air time are authored. The foam depth is arithmetic. Milk type changes foam a lot, plant milks especially, and this page does not give separate numbers for them. The 90-second sequence is a paper plan, not a timed trial.
Questions
Is a cappuccino the same as a latte with more foam?
In CupTune's build the milk is also far lower: 144 ml of total milk against 250 ml plus 14 ml of foam in the latte. The cup is smaller and the coffee is easier to taste.
Why do I need less milk than I think?
Because foam is mostly air. A 180 ml drink only needs about 120 ml of cold milk.
Can I use a 180 ml cup?
Only if you pour carefully. The drink is exactly 180 ml of liquid and foam, so a cup that size will overflow. Use 240 ml.