What it is and where it comes from
Lipase is an enzyme that breaks down fat. In cheese making it gives a sharp, tangy flavour, as in Italian Provolone and Pecorino. Some feta is made with it too. Animal lipase is taken from glands at the base of the tongue of young calves, lambs or kids (pregastric lipase) or from pig pancreas. Microbial lipase is made by fermentation.
Where you find it
Strong cheeses such as Provolone and Pecorino, some feta, butter flavours, and digestive supplements.
What to look for on the label
Labels often say only "enzymes". Look for a halal logo or "suitable for vegetarians".
This is a guide, not a fatwa. Recipes change, so check the label, look for halal certification, and ask your local imam where scholars differ.