The consensus seems to be that, unless you have something to bake right away in which you could use the buttercream, you should freeze it. That's right: don't toss that buttercream! It will remain good in the refrigerator for 4-5 days. Alternatively, put it in an airtight container and freeze it up to 3 months. When ready to use again, take out of the freezer and place in the refrigerator overnight to thaw.
The pH scale runs from 0 to 14, with each number assigned a different color. At the bottom of the scale sits red, which represents the most acidic, and a dark blue at its opposite end represents 14 and alkalinity. In the middle zone, the pH scale becomes neutral. Milk has a pH of 6 and a neutral off-white color.
pH is measured on a scale from 0 to 14; 7 represents neutral, where the water is neither alkaline nor acidic; 0 through 7 indicates acidity; and 7 through 14 indicates alkalinity.