Water activity

Water activity is like a measure of how much water is available for things to use. Think of it like a big bowl of water that different things want to drink from. Some things need a lot of water to survive, like plants, while others don't need as much, like ants. Water activity tells us how much water is available for different things to use. It is measured on a scale from 0 to 1, with 0 being completely dry and 1 being totally wet. So if something has a water activity of 0.5, it means half of the water in it is available to use. This is important for things like food because different types of bacteria and mold can grow in things with higher water activity, potentially making us sick. So we need to be careful about how much water is available in our food to make sure it stays safe to eat.