DIY Homemade Spray Starch on January 16, 2015 Because crisp and clean feel good! You’re going to love this easy homemade recipe for Spray Starch! It works just like store bought starch only a whole lot cheaper! With this easy and inexpensive recipe, you’ll want to stay home and iron all day! All you need is a spray bottle, water, and cornstarch. Who knew it was that easy! Just add one tablespoon of cornstarch to every 1 cup of water. Pour it in your spray bottle and your ready to iron. Because clean and crisp feel good!