What happened with my homemade bug repellent?
Asked by
El_Cadejo (
34610
)
November 21st, 2014
Ok so I’m currently living in Costa Rica, needless to say mosquitoes, sandflys and other biting insects are a bit of an issue. I don’t really like the idea of using DEET or other chemicals to repel them and it’s too bloody hot to wear layers so I’ve been making my own bug spray.
Normally what I do is boil lime zest, rosemary, basil, and mint to extract what I can from them and then add some aloe to the finished mixture. It’s been working for me quite well, better than the store bought bug spray actually.
This last batch I decided to add rubbing alcohol to the mix as that helps a ton with areas that are already itching. To my surprise when I added the rubbing alcohol the whole mixture congealed.
What caused this to happen?
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9 Answers
What’s the pH of the alcohol? Is it a base? You might of made soap.
@Adirondackwannabe It’s isopropyl alcohol so that should put it’s pH somewhere around 5.5. Wouldn’t I also need a lot more fats present to have produced soap. I mean the bug spray prior to adding the alcohol was mostly water, yea there are oils in it but I don’t think they’d be in high enough concentrations.
Then it probably curdled the oils and fats that extracted in your processing. That sounds like a great repellant, without the alcohol.
@Adirondackwannabe Possibly. I guess I’ll just have to keep them separate. I was trying to kill two birds with one stone, stop itching and prevent further bites.
hmmm maybe I should make some bug repelling soap, now there’s an idea….
Even tho it’s congealed, isn’t it still usable? You can still spread it onto your skin, right?
@Buttonstc Oh yea, totally usable just not in a squirt bottle. I was just curious about the chemistry of what was going on.
Cool recipe. I will have to try it. Can you list your portion sizes?
@Here2_4 I have a hard enough time doing that with food recipes :P I just throw a bunch of each ingredient into some water and simmer it for an hour or so. Seems like it’s enough to extract the oils from the herbs. It would be best to let them sit in there for a few weeks but as I’m traveling I don’t have time to do something like that. If I were you I would put all the ingredients into a food processor or something and then extract into a small bit of alcohol over the course of 3–4 weeks and then add that to the water.
It probably had more to do with the surface tension and the fact that you probably needed some form of emulsifier to get the alcohol to blend with the oil and perhaps what ever the aloe vera gel is suspended in. PEG 60 should work fine or if you want to really experiment, buy some lecithin.
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