I keep struggling with the goat milk I get. The people I get it from have the goats as pets. It started with one 4H project for their son but now they are milking 5 goats. When I collect some milk, I usually get around 15 gallon which is the milk from the previous three days of milking. Any milk older than three days I don't think is good anymore to make cheese from.
But even this fresh milk has not been so good. I had already post an entry about gas developing in lactic goat curd. After rereading mentioned book about farmstead goat cheese in this entry, my suspicion was affirmed. This premature bloating of the curd occurs frequently in warm weather. It is the result of contamination of the milk by coliform bacteria. These bacteria produce gas resulting in a spongy curd. The curd floats on top of the whey and a multitude of holes can be seen in the body. If the bloating is very pronounced, the vat can overflow, which happened to me recently. The author of the book says that the curd can be processed but can never produce a quality cheese. Indeed, the cheese I have produced from such curd tend to be on the dry side.
The author suggests several remedies. First he suggests to check the sanitary conditions of milking. In fact, I suspect that this is where most of the contamination arrives from. As said, the goats are just hobby goats and the milk is not produced for commercial reason. I get the milk for free so I don't want to be too demanding and make drawing the milk more difficult. But I have asked whether they mind washing the udders before they milk. I hope this will help reducing the contamination. Next, I might see whether I can find a filter for their milking system. I do find quite a few hair in the milk.
Another remedy the author suggests is to stimulate the acidification. I did a test and coagulated some of this milk without any starter culture. Because the acidification was not stimulated, the bloating was even more pronounced and the curd developed a nasty smell.
Another suggestion is to lower the curdling temperature. When I did this the curd developed less holes and did not float. I do not know though whether this milk was as badly contaminated as the curd shown here.