I've just added the citric acid and the culture to my milk and stirred. The milk instantly curdled and is sticking to the slotted spoon. Is this a toss out? And what happened?
No, I don't have a PH meter
Too much acid.
Yeah, I think so - darn wish those PH meters weren't so expensive.
I went ahead and made the cheese and it turned out very well - nice stretch and good ricotta from the whey. After cutting and draining the curds I let it hang out for an unspecified time - that is until I woke up on the couch and wondered where I was and what had become of my cheeses - and low and behold the PH must have been right. Ahhh, the nap o meter - right on.
When i started to make mozz with citric acid i found out that the milk starts to curdle at pH much higher than is acceptable for good stretching. I begun to add acid solution and rennet at low temp. 13 - 14C. Than i heated the mixture and proceeded as usual. That helped.
But when i tried to move up from 4,5 l of milk to 30 l, it appeared to be impossible to heat all entire volume from 14 to 32C without stirring. So now i add small portion of acid solution to hit pH 6.5 - 6.6 at 32C. than i add rennet. After cutting the curd i add slowly along with stirring and heating more acid solution to hit pH 5.0
So far i did it with one gallon batch. I want to give this method a try with 50l of milk soon. Hope it will work :)
"Without stirring"? Aren't you supposed to gently stir while heating the milk? I know about keeping the temperature rise at 2 degrees per minute, but no stirring? Hmmm...
Brian
I meant without stirring from the time i've mixed in the rennet till cutting the curd. If the temperature of milk is 14C we can wait for flocculation forever. And we can't stir the mix after rennet is already in.
Pavel is right, you shouldn't stir the milk after the rennet is added (except for 20-30 seconds to distribute the rennet). Stirring will break up the curd and won't allow it to achieve clean break.
When heating the milk from curding temperature (approx. 90 F) to the curd cooking temperature (approx. 105 F), how much stirring should you do? Just a gentle "move the curds" around? Or can it take more? Move the curds constantly? Vertical stirring? These were the questions rolling through my head the day I made my abysmal rubber bricks that were supposed to be my first cultured mozzarella! I wondered if I over-stirred while heating to the curd cooking temperature, and during the cooking process... hmmmm... books and photos only answer so many questions and no more... they aren't very good at carrying on an educational conversation while I'm toiling away!
Brian
There are two means by which you remove moisture from curds: heating, and agitation. The size of the curd combined with the stir and heat schedule determine the moisture content of the curds, which determines the moisture content of the cheese. Meaning the less you stir, the more moist the cheese will be. For a fresh mozz, the moisture target should be around 55%, which is quite moist, meaning your curds should be on the larger side, around 1/2", and you do not need to stir very vigorously.
rubbery mozz is likely not enough acid development or too dry or not enough fat in the milk.
If add propper determination of the flocculation point, using floc multiplier and the speed of rising the temp while heating curds (all these factors influence on the moisture of the cheese) it seems even more complicated to obtain consistent final results. The good news is one can make some improvements when working curds. :)