Failing to make mozzarella

Question

So i've taken it on me to make fresh mozzarella. I've read up on the task in some articles and with multiple recipes but for some reason I never succeed. The seperated curds always stay little crumbs and never take up the shape of solid blocks/curds/strands.

This is the recipe i'm following:

I use 1L pasteurized organic non-skimmed milk. It's non-homogenized milk but I don't know the pasteurisation temperature. I've used different brands. I dissolve a teaspoon of citric acid into 5 tablespoons of water. Adding this to the milk brings the pH to around 5.8. I've measured the amount of citric acid necessary to lower the pH of the milk to this acidity.

I then heat the milk to 30C. (i've also tried adding the citric acid to the milk at 30C instead of from the start). Once it has reached 30 degrees I take the pan off the stove, add 10 drops of microbiological rennet. The rennet is around 200 IMCU. Stir for 30 seconds.

Put the lid on, wait for 5 minutes.

Drain with strainer.

Result: poor crumbly curds, some even so fine they slip through the strainer. Cutting the curds is something i can't even think about.

Any mozzarella specialists here who could help out with this one? I don't want to give up on this endeavour but not sure if I want to keep wasting all this milk.

Answer 1

The problem is the organic milk. Or rather, the fact that organic milk available in grocery stores is high-temperature pasteurized, rather than conventionally pasteurized. That helps it keep a lot longer, but it disrupts the proteins so that they don't coagulate well enough for cheese.

I'm told that there are brands of conventionally-pasteurized organic milk, but I've never seen one. You might try it with plain old grocery store milk, and it should work. Or you could try to find a local producer, who won't use HTST pasteurization. (You might even be able to find unpasteurized milk, though the USDA definitely frowns on that: even though you're cooking it you won't have aged the cheese long enough.)

Answer 2

There's a couple things I think might help.

I think GdD is right, it sounds like your method is rushing things too much. After you add the rennet, you need to wait for the curd to set until it breaks cleanly - it might take longer than five minutes, try waiting at least ten... but mainly, go by the actual results not by time. Then you need to slice the curd into chunks, and let it sit again (5-10 minutes, I think), and then gently heat it up again for a bit to 105 or 110 degrees - all of which steps allow for the curd to release more whey (visually, the curd shrinks but also becomes firmer and easier to work with).

It doesn't sound like your method covers any of these steps - and actually it sounds like you're draining before you would be thinking about cutting the curd? or did I misunderstand? And, even if it's very fine and brittle curd, you can strain it through a fine cloth, and make a soft creamy cheese even if it isn't what you expected so the milk and time isn't quite wasted.

It would also probably be worth checking your milk for high-temperature pasteurization, as Joshua mentions in his answer. You might try regular milk, or even dehydrated milk if you can find any that isn't ultra-pasteurized, and if it makes a difference you can go looking for organic milk that isn't given the extra treatment.

Also, the recipe I've seen specifies the water must be un-chlorinated - you don't mention it either way, so I'm not sure if it is a relevant factor. If you don't have access to bottled or distilled or even filtered water, you can let the (plain) water sit overnight for the chlorine to evaporate. chlorine can stop the enzyme action of the rennet, interfering with the setting of the curd (the info is here but the question and answer is halfway down the page, sorry).

You might also try looking into additives, if nothing else is working. Calcium chloride is supposed to help curd set up more firmly. It's usually used more in making hard cheeses where the curd needs to set up pretty stiff to stand up to pressing, and it isn't recommended in making stretchy cheese like mozzarella because it can interfere with the stretching step, but you might try a moderate addition to see if it will help your curds, if absolutely nothing else is working.