Which cheeses have the most casein?

Cheese is not a food that happens to contain Casein. Cheese is a process for concentrating it.

Milk is about four fifths casein and one fifth Whey protein. Rennet makes the casein clump into curd, the whey drains away, and what is left is casein plus fat with the water squeezed out. Everything after that is a matter of how much more water leaves.

The ordering, and why it is structural

Most. Hard aged cheeses. Parmesan, pecorino, aged gouda, mature cheddar. Ageing is drying, and the US standard for cheddar caps moisture at 39 percent by weight, so what remains is protein and fat in a smaller volume.

Middle. Semi-hard and semi-soft. Everyday cheddar, gouda, edam, emmental.

Less. Fresh cheeses with high water content. Mozzarella, feta, cottage cheese, cream cheese.

Least. True whey cheeses. Traditional ricotta is made from the whey left over after another cheese, so it is built from the fraction casein was removed from. Modern supermarket ricotta is often made with added milk, which puts casein back.

What that ordering is good for

Not much, if you have a milk allergy. Every one of them contains milk protein, all of them are declared as milk, and an immune reaction is not a dose-ranking exercise.

It is useful for two other readers.

Anyone counting protein. Hard cheese is one of the densest protein sources in an ordinary shop, and that is the same fact seen from the other side.

Anyone told to reduce dairy rather than remove it. A ranking is only actionable if partial reduction is the instruction, and that instruction comes from a clinician rather than from a label.

The lactose ordering runs the other way

Worth knowing because people conflate the two.

Lactose is milk sugar and it leaves with the whey and then declines further during ageing, as bacteria consume it. So a hard aged parmesan is high in casein and very low in lactose, while fresh milk is the reverse.

Which means someone who is lactose intolerant often tolerates exactly the cheeses highest in casein, and someone with a milk allergy has to avoid those most of all. Two problems, two opposite rankings, one food. The distinction is set out on the page on casein and lactose.

Casein-free cheese

Plant-based cheeses are the only genuinely casein-free option, and even there it is worth reading the list. Casein gives cheese its stretch and melt, so some early plant-based products used it, which made them lactose-free and not milk-free. That is rarer now and a vegan certification mark rules it out.