We share your love of garlic. When my foodie wife and I first met for a blind coffee date, she didn’t ask about my religion, politics, or income. Practically her first question was “What do you think of garlic?”
Without hesitation I replied, “Garlic is the closest thing we have to proof of the existence of God.” And we have been cooking happily ever after.
First of all, garlic powder is not a good substitute for fresh garlic because in the process of being dried and powdered, garlic loses a great deal of its volatile flavors. But as you say, emergencies are emergencies. I won’t tell anybody if you don’t. (I use it on popcorn.)
Dried garlic was invented for the same reason as other dried spices and herbs: to preserve a perishable product. At the garlic powder factories they first break the bulbs down into cloves, smash them, and blow away the papery skins.
They then dry the naked cloves, remove any residual skin fragments. and powder the dried material. Much of our garlic powder comes from India and China, where both the raw garlic and the hand labor involved in processing it are relatively cheap.
But obviously, the fresh herb loses a lot of its “charm” in the process, so the dried and powdered product can’t hold a candle to the fresh.