Every cheese starts as milk, and the differences between a fresh soft cheese and a hard aged one come from a limited set of decisions applied differently.
Coagulation
Milk proteins are made to separate from the liquid, forming curds and whey.
Rennet, an enzyme, cleaves a specific protein allowing the others to bond into a network, producing a firm elastic curd.
Acid, produced by bacteria or added directly, achieves separation differently, producing a softer more fragile curd.
Which is the first fork — rennet-set cheeses can be aged and stretched, acid-set ones are generally fresh and soft.
Cutting the curd
Determines how much whey drains, which determines final moisture.
Cutting small releases more whey, producing a drier curd suited to hard cheese.
Cutting large or not at all retains moisture, producing soft cheese.
Which is a single decision with enormous consequences downstream.
Cooking and stirring
Heating the curds expels more whey and firms them.
Higher temperatures produce the very dry curds needed for hard grating cheeses.
Which is why the names of some traditional cheeses refer to the cooking process.
Salting
Draws out moisture, controls bacterial activity and seasons.
Applied as dry salt to the curd, rubbed on the surface, or by immersion in brine, each producing different rind and moisture characteristics.
Pressing
Compacts the curd and expels remaining whey.
Heavier pressing produces denser cheese with fewer openings.
Which is why some cheeses have holes from trapped gas and others do not — the pressing determined whether gas could accumulate.
Ageing
Where most of the flavour develops.
Enzymes from the milk, the rennet and the bacteria break down proteins and fats over months into hundreds of flavour compounds.
Which is why aged cheese tastes complex and fresh cheese tastes of milk.
Temperature and humidity during ageing determine the rate and the character, and traditional cheeses were shaped by the caves and cellars available.
Cultures and moulds
Specific microorganisms produce specific results.
Blue cheeses are inoculated with a mould and pierced to admit air, which is why the veining follows the piercing pattern.
Bloomy rinds come from a mould applied to the surface, which breaks down the cheese from outside in, producing the softening gradient.
Washed rinds are treated with brine, encouraging bacteria that produce strong aromas.
Milk
Species, breed, season, feed and whether it was pasteurised all affect the result.
Raw milk cheeses carry a more varied microbial population, producing more complex flavour and requiring careful production and regulation.
Rules on raw milk cheese vary considerably between jurisdictions and the age at which it may be sold is frequently regulated.
Storing it
Cheese is alive and continues changing.
Wrapping in plastic traps moisture and prevents breathing, which produces off flavours.
Waxed paper or cheese paper allows exchange while preventing drying.
Which is why cheese from a counter, wrapped properly, keeps better than the same cheese in plastic.
Serving at room temperature makes an enormous difference, since cold suppresses aroma perception and firms the texture.
Making it at home
Fresh acid-set cheeses require milk, an acid and a cloth, and take under an hour.
Which is a genuine introduction to the process and requires no equipment.
Rennet-set cheeses require rennet and more attention to temperature, and are still achievable domestically.
Aged cheeses require controlled conditions that most homes cannot provide, which is where the practical limit sits.
Pasteurisation
Heating milk to kill pathogens, which also kills the varied microbial population that contributes to flavour.
Which is why raw milk cheeses taste more complex and why they are regulated more carefully.
Thermised milk, heated less than full pasteurisation, is a middle position used by some producers.
Vegetarian cheese
Traditional rennet comes from animal stomachs.
Microbial and plant-derived coagulants exist and are widely used, and they behave slightly differently, which some producers say affects the result.
Labelling of which was used varies and is not universally required, which is why it can be difficult to establish.
Cooking with cheese
Melting behaviour depends on moisture, fat, acidity and age.
Young high-moisture cheeses melt smoothly. Aged low-moisture ones separate into fat and protein.
Which is why some cheeses become stringy, some become oily, and some do not melt at all.
Adding starch or acid, or grating and melting gently, all help with cheeses that would otherwise break.
Buying
Cheese cut to order from a wheel is generally in better condition than pre-cut and wrapped, since it has been stored properly and cut fresh.
Which is why counters exist and why the same cheese tastes different from different sources.
Tasting before buying is normal and expected at a counter.
Serving
Removing cheese from the refrigerator well before eating makes a substantial difference, since cold suppresses both aroma and texture.
An hour is generally cited for most cheeses, and harder cheeses benefit from longer.
Which is the simplest improvement available and costs nothing but planning.