Hello from New Jersey!
I'm new to this forum, and new to cheesemaking. For the sake of learning something new, I'm taking more of a science-based approach to my cheesemaking, and have been reading a ton about the chemistry of mozzarella.
I'm trying to make a batch right now using thermophilic cultures, but the pH isn't dropping.
I have 1 gal of grocery store whole milk (non-organic) being kept at precisely 100F using an immersion circulator. I checked the pH before adding anything and found it to be 6.57 using an Extech PH110, which I read about on this forum. To the milk I added 0.5g of thermophilic culture (half of a package that said would work on 2 gals of milk) and 1/4 teaspoon of calcium chloride (dissolved in 1/4 cup of water). I let the culture rehydrate before stirring it in.
The milk has been sitting with the culture in it for about 3 hours now. I've taken 4 pH readings (stirring before each one), and there has been no change whatsoever. pH is still 6.57.
Any ideas what I'm doing wrong? Not enough culture? Dead culture? Not enough patience?
How hardy are the cultures? This is my third attempt at cultured mozzarella, and all three attempts have used the same cultures. My curds looked good the previous two batches, but they wouldn't stretch no matter how long I waited. Thinking I was having some kind of pH issue, I bought the meter. Seems like dead cultures would explain why my previous two batches wouldn't stretch, and this batch isn't getting more acidic. Is this likely? Could the cultures have been killed by high summer heat during shipping? Or sitting in the warehouse too long?
Any help you provide will be greatly appreciated it.
Thanks!
I would guess the cultures are dead? Is this the only thermophilic type you have? How long have you had it?
The cultures are only a few weeks old, at least to me. I ordered them from Amazon, and have been storing them in the freezer since I received them. Not sure how long they were with Amazon, or what kind of conditions they were kept/shipped in.
Anyway, my wife and I were out for the afternoon, but I figured I'd leave the milk and see what happens. Turned the immersion circulator down to 88F (to slow the culture down, or so I thought), and left it for 7 hours.
So...3 hours at 100F and 7 hours at 88F and the pH is now down to 5.78.
Clearly, something is going on. Not sure if it's the culture I added, or something else.
A few questions:
1. What is the downside of adding rennet now?
2. Is it possible 100F was too high for the culture?
3. Are there any dangers to making mozzarella from this milk if the reason for the acidification is not the culture I added? I would think the very hot stretching water would take care of any bacteria, but I'm not sure.
4. Did I not use enough culture initially?
5. Any other ideas about what would cause such a slow acidification?
Again, thanks!