Baking Soda Expiration Date

I'm skeptical to trust shelf life guidelines, as they can be outrageously inconsistent and don't account for various factors. The general rule is that baking soda lasts for six months. If you question its freshness or it's been more than six months, you can assess its freshness by adding some vinegar to it. If the baking soda bubbles, it's still good. If it doesn't, it's past its prime. Throw it away. Test it out this way before baking an entire batch of baked goods and wasting other perfectly fresh ingredients.