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.
The pH is most commonly known as the measure of the acidity or alkalinity of a solution, numerically equal to 7 for neutral solutions, increasing with increasing alkalinity and decreasing with increasing acidity. The pH scale ranges from 0 to 14, most acidic to most basic [15]. In chemical terms, the pH scale refers to the concentration of hydrogen ions in a substance, and each whole unit represents a factor of 10 i.e. pH5 is 10 times more acidic than pH6 [16]. Basically a pH scale measures the concentration of H+ and OH-. The internal pH of most living cells is close to 7.