Okay, so imagine you really love cereal. And when you eat cereal, you notice that some pieces are big and some pieces are small. You really like the big pieces because they taste better to you.
Now, imagine someone wants to make cereal with only big pieces. But how do they make that happen?
Well, first they need to take special grains called malted barley and put them in a big room called an oast house. They spread the grains out on a special floor called a malting floor and let them sit there for a while.
During this time, something called germination happens. This is kind of like when a seed starts to grow into a plant. The grains start to sprout and grow little tails.
But then, something else happens. The grains are put into a special oven in the oast house called a kiln. This is like a really hot oven that gets up to around 200 degrees Fahrenheit!
When the grains are in the kiln, the heat stops the germination process and dries out the grains. This makes them hard and crunchy, kind of like big pieces of cereal!
Now, these big crunchy grains can be used to make all kinds of yummy things like beer and bread. And that's how an oast house helps make big, crunchy pieces of cereal!