30 Min. Mozzarella Turned To Ricotta

[Tropit]

A couple of my students at our cheese making class were trying to make the 30-min. mozzarella, but their curds never melted together.  Instead, they became like ricotta.  What went wrong?  Too much heat at the microwave stage is my guess.  I try to watch over their proceedures carefully, but in the chaos, I sometimes lose track of what they're doing.  I'd like to figure out what went wrong, so I can avoid the problem later.  Tips please.  :D

[tnsven]

The cheese was too acidic (can this happen with 30 minute moz?)? Or they used UHT milk?

Kristin

[linuxboy]

Most likely too much acid. When you get to about 5.3, sometimes 5.4, even at 95F, the curd falls apart with direct acidification. Directly acidified mozz needs a pH of 5.6. Sometimes you can get away with as low as 5.4. One of the many reasons I think if you're making directly acidified, you shouldn't without a pH meter. Milk is just too variable.

[Tropit]

Thanks...I think that might be the reason.  We all used the same milk, so that can't be the issue.  One of the students was not very careful in her details.  She may have measured wrong.  I had to stop her microwave because she had set it to 3.30 mins., instead of 30 secs.  Oh well...she was still happy to take home ricotta.  :D

[MrsKK]

So, you have a few different groups of students working on a few batches of cheese at the same time?  Sounds like happy chaos!  I'm glad she was satisfied anyway.