Plant milks foam by different chemistry from dairy, and only some are formulated for it.
Oat — the best
Barista oat milk is the closest to dairy. It textures into genuine microfoam, holds a pour, and is naturally sweet from the enzymatic breakdown of oat starches.
It is also the most stable against curdling in acidic coffee.
Standard oat milk is not the same product. Barista versions contain added fats — usually rapeseed oil — and stabilisers specifically to make foam work.
Soy — second
High protein, so it foams well. It curdles more readily in acidic coffee, particularly light roasts, and it carries a distinct beany flavour.
Barista versions are more stable.
Almond — difficult
Low protein and low fat. It foams thinly and collapses fast. Barista formulations help and it remains the hardest common option.
Also the most prone to curdling.
Coconut, rice, hemp
Rice foams poorly. Coconut can foam and carries a dominant flavour. Hemp is variable.
Why barista versions matter
They are not marketing. They add fat, protein and stabilisers — often dipotassium phosphate to buffer acidity and prevent curdling.
Technique differences
Plant milks generally want a lower temperature — 55 to 60 °C — and burn or split above 65 °C.
Stretch slightly less. They expand more readily than dairy.
Last reviewed 8 August 2026