People use the two words as though they were interchangeable. They are not, and the difference is not a matter of degree or of quality: burrata and mozzarella part company halfway through being made, and by the time they reach a table they want completely different things from you.
Here is what actually happens in the dairy, what changes between the two, and why one of them tastes so much better here than it does anywhere else.
The part they share
Both are pasta filata, which translates as spun curd and describes a technique rather than a cheese. The family includes provola, scamorza, caciocavallo and a dozen others, and what unites them is a step that happens nowhere else in cheesemaking.
From milk to curd
Milk is warmed and soured, either with a starter culture or with whey kept back from the previous day's work, which is the older method and still common in small dairies. Rennet goes in, and within half an hour the milk sets into a soft white solid.
The curd is cut, which lets the whey run out, and then left alone. This is the part that cannot be hurried and that decides everything downstream: the curd has to acidify to a narrow window, somewhere close to pH 5.2, before it will do the one thing the whole family depends on.
The spinning
At that exact acidity, and not before or after, the curd changes behaviour. Put it in water at around eighty degrees and it stops being a crumbly solid and becomes elastic: it stretches, folds, and takes a shine, behaving more like warm dough than like cheese.
The cheesemaker works it with a wooden paddle and then with bare hands, pulling and folding until the mass is smooth and glossy and comes together in a single rope. That is the spinning, and watching it done well is the most persuasive argument for artisan cheese anyone has ever made.
Everything up to here is common to both. In Puglia the milk is cow's milk, and what comes out is called fiordilatte at home, whatever the menus abroad print. Buffalo mozzarella is a different animal in the literal sense and belongs to Campania, one region west.
Where they separate
Mozzarella is the rope, closed
A piece is pinched off the rope and shaped into a ball. Mozzare means to cut off, and the name is a description of that last gesture, performed with the side of the hand.
The result is one material all the way through: firm, springy, faintly sweet, tasting of the milk it was made from and very little else. Fresh, it leaks a little milky liquid when cut, which is the sign to look for. A ball that cuts dry has been sitting.
Burrata is the rope made into a container
Instead of closing a ball, the cheesemaker flattens a sheet of the hot curd into a thin pouch, a pocket the size of a cupped hand. Then fills it.
The filling is two things. Ragged strips of the same spun curd, torn by hand rather than cut, and fresh cream. The strips have their own name, stracciatella, from stracciare, to tear, and you will find them sold on their own in tubs across Puglia, which is one of the great small pleasures of shopping here.
The pouch is gathered at the top and tied, traditionally with a blade of leaf from an asphodel plant, now usually with string or with a twist of the cheese itself. That knot is why a proper burrata looks like a little white purse, and why it is served knot upwards.
So: mozzarella is a cheese. Burrata is a cheese with something else inside it. Cut one open at the table and the difference is not a nuance, it is a small event.
It was invented to use up the scraps
The best origin stories in Apulian food are about thrift, and this one is no exception.
Working the curd leaves offcuts: ends of rope, torn bits, pieces too small to shape. In the countryside around Andria, in the north of the region, someone worked out that those scraps, plus cream, wrapped in a sheet of the good stuff, made something better than either part alone. It also solved a transport problem, since a cheese wrapped in cheese survives a cart journey rather better than loose curd in cream.
It caught on for the obvious reason, and burrata from Andria now carries a protected designation, which is unusual for a cheese invented so recently and tells you how seriously this corner of Puglia takes it.
Its enemy is the clock
This is the single most useful thing to know, and almost nobody outside the region is told it.
Mozzarella keeps reasonably well in its own liquid: a few days, gradually firming and losing sweetness. Burrata does not keep, because the cream inside is fresh cream and behaves like fresh cream.
- Day one. Sweet, milky, the filling loose and almost liquid. This is the cheese people write home about.
- Day two. Still good. The cream has thickened slightly and the outer pouch has firmed.
- Day three and beyond. The cream turns faintly sour, the pouch goes rubbery, and the whole thing starts tasting of the fridge.
Which explains something visitors notice and rarely hear explained. Burrata tastes different here, and it is not local pride or the romance of the holiday. It is that the cheese on your plate was made this morning by someone twenty minutes up the road, and the one you buy at home left a dairy five days ago at best.
How to tell a good one before you open it
- It should be heavy for its size and slightly slack in the hand, not taut like a ball.
- The pouch should be bright white and smooth, with no yellowing at the knot.
- The liquid in the tub should be cloudy and smell of milk. If it smells of nothing, the cheese will too.
- Ask when it was made. In Puglia this is a normal question with a precise answer, and a shop that cannot give one is telling you something.
How not to ruin either of them
Temperature
Take both out of the fridge at least half an hour before eating, an hour in winter. Cold flattens the aroma of fresh cheese almost completely, and this is the mistake nearly everybody makes, including restaurants that should know better. A burrata served straight from the fridge is a texture with no flavour attached.
Do not cook burrata
It is not a topping to be melted. Heat splits the cream and you are left with a greasy puddle where the best part used to be. If it has to meet something hot, let the hot thing come to it: pasta taken off the heat, a roast tomato set beside it, a slice of bread still warm from the oven.
Mozzarella is the sturdier of the two and belongs on anything baked. Tear it rather than slicing it, and let it drain for a few minutes first if it is going into the oven, or it will water down whatever it lands on.
What to serve with it
Good oil, salt, pepper if you like. Bread. That is the whole list, and most additions are in the way. If you want something beside it, keep to things that are already part of the same landscape: ripe tomato, a few olives, raw broad beans in spring, grilled peppers in summer.
Cut it open at the table rather than in the kitchen, so the inside spills where people can see it happen. Serving it pre-cut is a small waste of the only theatre this cheese has.
Wine, if you want one
Something white, cold and unoaked. The local Locorotondo is made for exactly this and costs almost nothing here. A dry rosé, of which Puglia makes a great deal and some of it very good, works as well.
Stracciatella, the useful middle
The filling on its own, sold in tubs, and the most practical of the three for cooking. It has the flavour of burrata without the pouch, so it can be spooned rather than cut, which suits it to pasta, to bruschetta, to a plate of grilled vegetables.
It keeps no better than burrata does, and the same rule applies: buy it the day you intend to eat it, and ask when it was made.
A note on what travels
None of this is an argument that burrata abroad is worthless. It is an argument that it is a different food: firmer, milder, further from the milk. If that is what you have available, treat it as its own thing and do not wonder why it does not taste like the holiday.
What travels genuinely well from this region is the aged end of the same family: caciocavallo, scamorza, ricotta salata. Those are built to keep, and a wheel of good caciocavallo is a much better thing to carry home than a burrata that will be three days old before you land.
Go and watch it being made
Reading about spun curd is fine. Standing in a dairy at the hour the milk comes in, watching a pair of hands pull a rope of curd out of hot water and close it into a ball in one unhurried movement, is a different order of understanding, and it takes about four minutes.
We take guests to the producers we buy from, and this is usually the stop people talk about afterwards. You taste the cheese warm, which almost nobody outside a dairy ever does, and you stop confusing the two words for good.