TEMPERATURE
Stop at about 60 °C
That is the usual café target, and studies found the milk’s nutrition largely intact up to about 65 °C.
Try the temperature checkA latte is mostly milk, so the milk deserves the attention.
Food scientists have measured how milk foams, how temperature changes it and what fat and protein do to the bubbles. Add what Europe’s food safety authority says about caffeine and you have the whole drink, in plain English.
Plain English, with the sources linked.
- Steam to about 60 °C
- Choose the milk
- Count the shots
- Mostly milk, carefully
THE SHORT ANSWER
Warm it, don’t cook it.
Three things decide a latte:
how hot, which milk, how many shots.
THE MILK
Fat and protein change the foam
Skim milk forms very stable foam; more fat makes it creamier but less stable.
See the studies
CAFFEINE
It is in the espresso
A 60 ml espresso holds about 80 mg of caffeine. The milk adds none, so the shots decide.
How much is fine?
MAKE A BETTER ONE
Four habits
for a better latte.
Stop before it is too hot to hold
Aim for about 60 °C. Until you know the feel of the jug, a clip-on thermometer takes out the guesswork.
Pick the milk for the foam you want
Lower-fat milk gives firmer, longer-lasting foam. Whole milk gives a richer, looser one. Both are fine; they are just different.
Don’t reheat it to boiling
Reheating a cooled latte to scalding undoes the gentle steaming and, by the research, costs some vitamins.
Know your shot count
A double-shot latte can carry around 160 mg of caffeine. EFSA’s single-dose figure for healthy adults is 200 mg.
TWO STUDIES WORTH KNOWING
The milk matters
as much as the method.
What goes into the jug changes
the foam that comes out.
More fat, less stable
Milks tested, from 0.5% to 3.5% fat
Danish researchers steamed milks of different fat and protein levels on a café espresso machine. Higher fat made the foam less stable but drain less, while more protein slightly increased the foam’s volume.
FAT AND PROTEIN · 2015
Pasteurised > UHT
Steamed from 40 to 80 °C
Italian researchers found pasteurised milk formed a more stable foam than UHT milk, which they linked to milk proteins such as beta-lactoglobulin and lactoferrin.
PROCESSING · 2023
Neither result says one milk is “right”. A creamier, looser foam suits some drinks; a firmer, longer-lasting foam suits others.
A QUICK TEMPERATURE CHECK
How hot is
your milk?
Pick a steaming temperature to see what the research says happens to the foam and to the milk itself. The figures come from dairy studies published between 2008 and 2023.
A kitchen thermometer clipped to the jug is the easiest way to learn what 60 °C feels like through the steel.
MILK FACTS
Five things worth
knowing.
About 60 °C is the norm
Researchers describe milk for a cappuccino as normally steamed to about 60 °C, and a traditional cappuccino as 25 ml of espresso with 100 ml of steamed milk.
Foam has a sweet spot
A 2008 study tested milk from 5 to 85 °C. Skim milk foams were most stable when formed at 45 °C, in line with a 2010 review that found them very stable at 40 to 50 °C.
Cold fat fights foam
At about 20 °C milk fat is partly crystalline, and that is where it harms foam most. Fat cut foam formation in whole milk between 15 and 45 °C; homogenisation and UHT treatment softened the effect.
Overheating costs vitamins
Milk steamed to about 60 to 65 °C kept its nutritional quality largely unchanged. At higher temperatures, vitamin B6 and folic acid fell.
Caffeine comes from the shots
A 60 ml espresso has about 80 mg of caffeine. EFSA found no safety concerns for healthy adults with up to 400 mg a day, or single doses up to 200 mg.
QUICK QUESTIONS
Lattes, answered.
Short answers to the questions people ask most.
What temperature should milk be for a latte?
Researchers describe about 60 °C as the normal steaming temperature for milky espresso drinks. A 2023 study found the milk’s nutritional quality largely unchanged at about 60 to 65 °C, while higher temperatures reduced some vitamins.
Which milk makes the best foam?
In laboratory studies, skim milk forms very stable foams, and milk fat tends to reduce how well foam forms and lasts. A 2015 study found that more protein slightly increased foam volume, while more fat made foam less stable but drain less.
Why does some milk foam differently from others?
Composition and processing both matter. A 2023 study found that pasteurised milk formed a more stable foam than UHT milk, which the authors linked to milk proteins such as beta-lactoglobulin and lactoferrin.
How much caffeine is in a latte?
Most of it comes from the espresso. EUFIC, summarising EFSA, lists about 80 mg of caffeine in a 60 ml espresso, though the amount varies with the beans and how the coffee is made. A latte with a double shot will carry more than one with a single.
How many lattes a day is too many?
EFSA concluded that up to 400 mg of caffeine across a day, and single doses of up to 200 mg, raise no safety concerns for healthy adults. For pregnant and breastfeeding women the figure is up to 200 mg a day. This is general information, not personal advice.
Sources
Each figure on this page comes from the sources below.
- Effects of different steam injection conditions on cappuccino’s nutritional profile (Santini et al.)Food Chemistry, 2023
- The influence of temperature on the foaming of milk (Kamath et al.)International Dairy Journal, 2008
- Foaming properties of milk: a review (Huppertz)International Journal of Dairy Technology, 2010
- Steam-frothing of milk for coffee (Münchow et al.)International Dairy Journal, 2015
- EFSA opinion on the safety of caffeine, explainedEUFIC
- Scientific opinion on the safety of caffeineEFSA Journal, 2015