204 UNSWEETENED ConpbENSED Mik Derrcrs 
enzymes, and while these different species of micro-organisms 
come from a variety of sources, the most common sources are, 
the soil, pasture, water and the udder itself. It is a noteworthy 
fact that this defect is most commonly found in milk and milk 
products when the cows are on pasture. It is, therefore, probable 
that, in most cases, this troublesome germ is carried into the milk 
on the farm. 
Again, in summer, at a time when this defect generally 
occurs, the effect on the cows of the summer heat and flies, and 
the tendency toward high acid in milk, render the milk most 
sensitive to the sterilizing heat. ‘Phe operator finds it difficult 
to avoid the formation of a disastrous curd in the sterilizer. In 
order to guard against this trouble he is tempted to either lower 
the temperature, or shorten the duration of the sterilizing process. 
This tends towards incomplete sterilization. A very frequent 
result of this incomplete sterilization in the late summer 
months, is the formation of a bitter curd. When the processor 
returns to the proper sterilizing process, the occurrence of bitter 
curd in the cans disappears and the product is normal. 
A further safeguard against the recurrence of this trouble 
lies in providing for uniform distribution of heat in the sterilizer. 
If the cans have to be stacked in deep tiers, which is un- 
desirable and should be avoided, slats should be placed over 
the top of every second row of cans. This will make possible 
the free access of steam to at least one end of each can. Tf the 
circulation of steam in the sterilizer is poor, the uniform distribu- 
tion of heat can be facilhtated by filling the sterilizer about one- 
third full of water so that, with every revolution of the frame- 
work, the cans have to pass through this water once. ‘The water 
reaches every nook in the interior of the sterilizer, distributing 
the heat much more uniformly than the steam. Uneven distribu- 
tion of the heat may also be due to an improper condition of the 
steam-distributing pipe located in the bottom of the sterilizer. 
Some of the perforations in this pipe may have become too large 
by wear, or may have become clogged with scale or the cap 
at the end of the pipe may have come off. In all of these cases 
the distribution of the heat in the sterilizer is found to be irregular, 
interfering with the untformity and dependability of the proce§s 
of sterilization. The processer Should make sure, by daily in- 
