This reaction causes the temperature to go up. Place 1 tablespoon of vinegar in a cup. Put the thermometer in the cup. Hold the thermometer and cup so they do not fall over. Read the temperature and ...

Substitute 1/2 tsp of baking soda for 1 tsp baking powder and 1 tsp vinegar or lemon juice. How long do they last? Baking powder has a shelf life of 3-12 months. If you live in a humid climate ...