No, it's just hard to make traditional mozzarella, it takes more than a day and careful control of acidity. The "30 minute" recipes are faster and easier because they substitute the long acidification of the traditional recipes with instant acidification (with citric acid, vinegar etc) but they have a very high failure rate. If you search for "mozzarella" on r/cheesemaking you can see that maybe one out of three are from people who couldn't make it work:
That must be an underestimate too, because the people most likely to post on reddit to tell everyone about their mozzarella are the ones who had a "success!!!" with it.
https://www.reddit.com/r/cheesemaking/search/?q=mozzarella&r...
That must be an underestimate too, because the people most likely to post on reddit to tell everyone about their mozzarella are the ones who had a "success!!!" with it.