Although Romano cheese is traditionally made in Italy from ewe's milk (Pecorino) the following recipe is prepared for a 2 gallon version of cows milk (which would technically be called Vacchino Romano).
Strength is usually tested by measuring permanent deformation of the container. Hydrostatic testing is the most common method employed for testing pipes and pressure vessels. Using this test helps maintain safety standards and durability of a vessel over time.
This would not be the case. with hydrotest with water as test fluid. Gas at high pressure will eject out of a crack at. much higher velocity and cause more havoc than water which will ooze out at velocities. which are order of magnitude less. Also, even if few drops of water exit a pressurized.