Part of my intense nerdyness comes from my childhood when I was obsessed with fire. Yes, like many young boys, I was a pyromaniac. And I still am. I’m just a much safer, more cautious pyromaniac. Every year for the 4th of July I like to indulge my inner 14-year-old boy by buying and even making my own pyrotechnic devices. I thought I would share one recipe/method for making a homemade smoke bomb. It’s pretty simple and safe- provided you follow these directions very carefully.

Ingredients: Equal parts sucrose (aka table sugar) and potassium nitrate (aka saltpeter or KNO3), a container, and a fuse. (Just pull a fuse out of a bottle rocket.)

Saltpeter is relatively easy to come by if you know where to look- it can usually be found in small mom & pop drug stores (never chains like Walgreens for whatever reason…) or in hardware stores where it’s sold as stump remover. There are several different kinds of stump remover but the one you need is usually called “stumpout.” Just check the label and shake it to make sure it’s really potassium nitrate in powder form. I used stump remover in the one I made last year and it worked great.

Mix the KNO3 and sugar (equal parts) together well and put them into a saucepan or pot. Heat the mixture in the pot VERY SLOWLY on an ELECTRIC stove eye. Let me say that again- heat it VERY VERY SLOWLY on an ELECTRIC stove eye. DO NOT heat it on a natural gas stove as it will greatly increase the risk of accidental ignition. The electric stove eye provides a slower, more gradual source of heat. Obviously, the best place to do this is OUTSIDE on a portable heat plate, and be sure you wear some kind of eye protection. Carefully monitor and stir the mixture and as soon as you notice it starting to melt, turn the heat back down just a bit- you want the bare minimum amount of heat necessary to melt the mixture. It will begin to turn a brownish orange color- keep stirring and monitoring the temp. Once it’s all a gooey liquid, pour it into whatever container you’ve chosen and insert the fuse. Simply allow it to cool and harden and you’re good to. Don’t try to make a really huge one, either- if the chunk is too big it will burn too fast and potentially explode. Here’s a great video of the final product in action:

The powder form of this mixture (pre-melting) will burn quite well and produce a lot of smoke, but the melting allows the fuel and oxidizer to blend in a way that the powder form can’t. This is why the melting method yields a steadier, smokier burn.

The most important thing here is safety: