I had a late blower once...
Late blowing is caused by clostridium tyrobutyricum spores in the milk. Pasteurisation kills clostridium but not the spores.
If cows are fed with ensilage the risk of clostridium is higher than if fed on grass/hay. I use something called Lysozyme when not using grass-/hay-milk. This minimizes the risk of late blowing.
Swelling of a cheese can be a sign of late blowing (if not intended with propionic bacteria etc.). The image below shows my late blower Asiago.
When I cut the cheese I could actually hear a a short sound of gas escaping. I smelled the cheese/gas and it smelled a like vommit. It's actually the smell of butyric acid produced by the clostridium.
The cheese had a big crack in the middle where the gas expanded, and that's also a typical sign of late blowing...
:-) Danbo
