Here’s how to make your own Baking Powder in less than a minute.
1 teaspoon baking soda
1 teaspoon cream of tartar
Mix both together and you have Baking Powder.
After you get your submarine ready, put some Baking powder in the bottom and let it sink to the bottom.
The baking powder will come in contact with water, which will in turn cause a chemical reaction. This reaction will produce air bubbles along the bottom of the potato, causing it to rise back to the surface. When the submarine gets to the surface, the bubbles will break and the submarine will sink back down again.
After potato is ready test it by letting it sink to the bottom. It should sink slowly. If it sinks fast then cut some potato off. I cut to much off and add some back and held it on with a toothpick. If it floats then add some potato back on.
It’s tricky, but awesome once you have it down.