Salt and other flavorings make up the rest of the cheese.

These micelles link together into long chains, forming a matrix that gives the cheese structure. These proteins come together head first in bundles of several thousand, protecting their hydrophobic heads, and exposing their hydrophilic tails. Individual milk proteins (the main ones are four similar molecules called caseins) resemble little tadpoles, with hydrophobic (water-avoiding) heads, and hydrophilic (water-seeking) tails.

Protein micelles are spherical bundles of milk proteins.

Because of this, and because of their suspension, the fat globules don't come into contact with each other to form larger globules: cheeses stay creamy or crumbly instead of greasy. Under around 90☏ (32☌), the fat is solid.

In solid cheese, milk fat is suspended in the form of microscopic globules held in a tight matrix of protein micelles (more on those in a second).

Famous hard cheeses, like Parmigiano-Reggiano or Pecorino Romano may be as little as 30% water after several years of aging.

The longer a cheese is aged for, the more moisture it loses, and the harder it becomes. Young cheeses like Jack, mild cheddar, or mozzarella have a relatively high water content-up to 80%. Grate the cheese and stir in until it’s melted. Cook for another minute or so, stirring occasionally. Keep going until the mixture is lovely and smooth, and there are no lumps.Gradually add the milk, stirring as you go and ensuring each new addition is fully incorporated before adding the next.Stir in the flour for 1 minute to make a paste – this is called the roux.When the butter has melted, add the flour.Melt the butter in a medium saucepan over a medium heat.Here’s a step-by-step guide to basic cheese sauce: Take your cheese sauce up a level by adding garlic, thyme, rosemary or bay leaves, mustard, a grating of nutmeg or plenty of freshly ground black pepper – it’s a great vehicle for other flavours. The trick is to get the sauce silky smooth, which is easy to do as long as you add the milk gradually, stirring constantly so that each new addition is fully incorporated before adding the next. Whether you’re making a Killer Mac ‘n’ Cheese, a comforting lasagne or a cauliflower cheese, you’ll need to know how to make cheese sauce.

How to make a cheese sauce from scratch