6–8 cups hydrated lime *Also known as builders lime or masonry lime. This is different than the garden lime that you might sprinkle on your barn floor.*
2 cups salt
1 gallon of water
Combine all the ingredients in a bucket and mix well. (A wire whisk worked the best for me.)
You are looking for the whitewash to be the consistency of pancake batter, so add more lime or water if you need too. Don’t get hung up on exact measurements—I sure didn’t. Sometimes letting it sit for an hour or two will help it to thicken a bit.
Use a paintbrush or roller to apply it to the wooden surfaces of your coop, barn, or milking parlor.
Let it dry (it will turn white as it dries) and enjoy the fruits of your old-fashioned labor!