The distribution of salt in butter is of importance from the standpoints of uniformity of composition and color, distribution of moisture and deterioration through action of micro-organisms. Various investigators, using macro-methods of analysis, have studied the distribution of salt in butter, particularly in connection with controlling the composition and preventing certain color defects. The information obtained is very useful, but it is not adequate in considering the relationship of salt to bacterial changes in butter.

The retarding effect of salt on the activity of many micro-organisms is generally recognized, and various investigators (8) have· noted that addition of salt to butter limits the action of bacteria in it. However, butter containing relatively high percentages of salt sometimes undergoes bacterial spoilage.