The streams of skim and cream after separation must be recombined to a specified fat content. This can be done by adjusting the throttling valve of the cream outlet; if the valve is completely closed, all milk will be discharged through the skim milk outlet. If the valve is very slightly opened, you get most of the fat globules in a very small volume of skim, so cream with a high fat content. As the valve is progressively opened further, larger volumes of skim push the fat globules out, so you get larger volumes of cream but with diminishing fat contents (%) being discharged from the cream outlet. With direct standardization the cream and skim are automatically remixed at the separator to provide the desired fat content (see the diagram above to explain the automatic standardization process) . Some basic standardization problems including mass balance and Pearson square approach can be viewed on the following page.