I have done 2 makes now with the milk from the Jersey cow where I am volunteering. In both cases, the initial pH before adding starter is 6.5 (taken after cleaning, checking calibration and at 75 to 80 degrees). The animal is milked with a machine which has been cleaned with Hi-Chlor, and allowed to drain well. It takes about 40 mins to milk her and finish her needs, then the milk is transferred to buckets, weighed, and poured into jars I have cleaned and sterilized with star san at home. The jars are then placed in the frig on site which is not very cold, for another hour of tasks. Then I put them in a large ice chest with 3 bottles of frozen water, and drive them 15 mins to home.
The result both times is that I am chasing the pH drop the entire make and worrying about over acidification. I am guessing that the native bacteria are starting to work in the 2 to 3 hours between milking and starting my makes. In both cases, I think the milk was no lower in temp than about 60 degrees, and I have read somewhere that it should be chilled to 40 degrees? Do I need to come up with some other way of chilling the milk more quickly?
Normally, I look for the pH to drop from 6.6 to 6.5 to add the rennet. But I am already there by the time I get home. Could I put my desired starter in and let it rehydrate for 5 to 10 mins and then go ahead and rennet without the ripening period? Could I see what happens with no starter at all?
The milk seems lovely, smells wonderful, tastes great, and others are drinking it and making yogurt, or ice cream with the cream. So I think it is safe. I will let the cheeses age out the 60 days at any rate...