Mix 1/4 teaspoon of baking soda into 2 teaspoons of vinegar.
If it bubbles, it's fresh.
Mix 1 teaspoon of baking powder into 1/3 cup of water.
If it barely bubbles (above) or doesn't bubble at all, don't use it. It will not make your baked goods rise.
Fill a cup with water and gently place the egg so it doesn't crack. If it balances on the pointy end (above) it is losing freshness. If it floats, do not use.
Gently place the egg in a cup of water. If it sinks on its side, then it's fresh. Thanks for viewing. For awesome napkins, please click on http://goo.gl/wRi61C