Users create this software themselves and often overlook how important it is. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or Microwave Oven.
You can jam milk through pretty small holes with force like that. Before homogenization, fat globules range in size from 1-10 microns (a micron = ~0.00004 inch). After, the size range is reduced to 0.2-2 microns.
The FDA and CDC warn against the dangers of unpasteurized milk and in some states, selling it directly to consumers is illegal. Other states allow the sale of unpasteurized milk directly to consumers, but could have strict laws for distributing the item across states lines. Homogenization is an entirely separate process that occurs after pasteurization in most cases.