how do I test baking powder for freshness?

Z..8 years ago
Hot water! Put a teaspoon of it into a cup, and pour very hot water-about a dessertspoon full on it. If it foams, it's good to go!
orksecurity8 years ago
Second Lemonie's comment. I've been using the same can for a decade.
lemonie8 years ago
As an inorganic material, baking powder doesn't lose "freshness" like perishable foodstuffs. The worst that will happen to it is that it will get damp - which should be noticeable from it's appearance. If it's not a dry and free-flowing powder it's "gone-off" a bit. If it's a solid-lump it's "gone off" a lot. L