Salt & pH
These are the two levers that decide what the cheese becomes once you’ve stopped handling it. Get them right and a wheel ripens the way the recipe says. Get either wrong and no amount of careful technique earlier in the day will save it.
Salt does four jobs, and flavour is the least of them
Salting a cheese is not seasoning it.
It draws out more water. Osmosis, on top of everything the curd page already did. Salting is the last significant moisture removal before aging.
It slows the bacteria down. This is the big one. Your starter has been racing all day; salt applies the brake so that ripening happens over months at a walk instead of over days at a sprint. An under-salted cheese doesn’t taste bland — it over-acidifies, goes pasty or crumbly, and can ripen into something unpleasant.
It makes the surface hostile. Salt lowers water activity, and a great many organisms you didn’t invite cannot cope with a salty, drying rind.
And it changes the protein. Salt affects how casein holds water, which is part of why salted curd firms up noticeably.
Which is why recipes that say “sprinkle with salt” are asking you to guess at one of the two variables that matter most. If a recipe gives a percentage of curd weight, weigh the curd and hit it.
The three ways to salt
On the curd, before pressing — the cheddar method. Mill the curd, scatter measured salt, mix, then press. Gives the most even distribution, because the salt is inside from the start.
On the surface, rubbed on a formed wheel and repeated over days. Traditional for several washed and natural-rind cheeses.
In brine, floating the wheel in salt solution. Standard for gouda, alpine cheeses, feta, mozzarella and many more. And it has a trap in it.
🔴 The brine trap: your brine will eat your cheese
This one is worth the whole page, because it is a defect people meet, blame on their technique, and never diagnose.
Make a plain saturated salt brine, float a wheel in it, and come back to a cheese whose surface has gone soft and slimy at the edges.
Here’s why. A cheese is a protein network held together by calcium. Put it in a brine containing no calcium and you have created a concentration gradient — so calcium leaves the cheese and dissolves into the brine, and keeps leaving until equilibrium is reached. One source puts it perfectly: it is like pulling the mortar out of a brick wall. The surface loses its structure and goes to slime.
The fix is to put calcium in the brine before the cheese goes in.
- 0.1% to 0.3% calcium chloride in a new brine, with 0.25% the commonly recommended figure — which is 2.5 g per litre.
- And lower the brine’s pH to around 5.0 when you make it up. The slimy defect is also caused by a pH mismatch between the cheese and the brine; bringing the brine near the cheese’s own pH removes that gradient too.
- Then maintain it. As wheels give up whey into the brine, the brine dilutes. Calcium concentration needs monitoring and topping up if you reuse it, which everybody does.
Nobody’s first cheesemaking book told me this in those terms. It is the difference between a brine that works for years and one that quietly ruins every wheel you put in it.
pH: the number the whole make is actually steering
Reading a recipe makes the general argument — the clock is a proxy, the pH is the instruction. This is what the number is doing at each stage.
Fresh milk sits around pH 6.6–6.7. Rennet’s enzymatic phase runs happily at about 6.4–6.5, which is essentially fresh milk. If you let the culture run too far before adding rennet, you’re already partway down the acid route, and you’ll get a mixed, weak, brittle curd instead of a clean gel.
Through the make the pH falls as the starter converts lactose to lactic acid. Where you are on that curve when you cut, when you cook, when you drain and when you salt determines almost everything about the finished cheese.
And it decides how much calcium stays in the protein. This is the mechanism that ties this page to melting and to texture generally: lower pH means more of the calcium leaves the casein network and goes into solution. A high-acid cheese has lost much of its calcium cross-linking, which is why it is crumbly. A higher-pH cheese has kept it, which is why it is springy and elastic.
That’s the whole reason washing the curd works — remove lactose, less acid, higher final pH, more calcium retained, springier cheese.
Rough targets
Approximate, because they vary by style, and this is the shape rather than a specification:
| Stage | Roughly |
|---|---|
| Fresh milk | 6.6–6.7 |
| At renneting | 6.4–6.5 |
| At cutting | 6.4–6.5 |
| At draining | varies hugely by style |
| Cheddar at milling | ~5.3–5.4 |
| Pasta filata at stretching | ~5.2–5.4 — and the window is narrow |
| Finished hard cheese | ~5.0–5.3 |
| Acid-set fresh cheese | ~4.6 — casein’s isoelectric point |
The pasta filata line is the one where this stops being theory. The curd will only stretch inside a narrow pH band, roughly twenty minutes wide in practice. Too early and it tears; too late and it turns grainy and won’t come together. Nobody hits that window reliably on a clock.
If you buy one instrument
A pH meter, and then calibrate it far more often than the instructions suggest. Cheap meters drift, and an uncalibrated meter is worse than none because it is confidently wrong. Buffer solutions are cheap; use them.
Which meter, and how to keep it alive, is written up on Measuring pH over in Preservation. ⚠ Note that page is written around a safety threshold and this one is not — nothing in cheesemaking turns on pH 4.6. Here the number is process control: it tells you when to cut, drain, mill and salt. Same instrument, same calibration discipline, different reason for owning it. The spear-tip probe it recommends is the right shape for a curd.
If you’re not ready for that: the flocculation multiplier and the clean break on the curd page both measure your own vat and cost nothing.
Next: ripening — what actually happens over the following months, and why aged cheese crunches.
Sources
- Calcium in brine: cheese in a calcium-free brine develops a soft, slimy surface because the brine draws calcium out of the protein complex; 0.1–0.3% CaCl₂, commonly 0.25% (2.5 g/L); brine pH lowered to about 5.0; and the need to maintain calcium as brine dilutes: New England Cheesemaking on salt brine, Moorlands Cheesemakers on the slimy defect and Effect of calcium in brine on salt diffusion, J. Dairy Sci.
- The positive correlation between pH and insoluble (network-bound) calcium: Determination of insoluble calcium content in Cheddar, feta, Juustoleipä and mozzarella
Comments (0)