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.
Litmus Paper. Litmus paper is the most recognized member of chemical indicators. Like most pH paper, litmus changes color when exposed to an acidic or basic solution. The simple pH scale ranges from 0-14 with 0 being the most acidic, 7 being neutral, and 14 being the most basic or alkaline.