Bug Repellent Coffee Grounds?

13042014 (14)A little while ago, I was scanning Facebook and came across an article claiming that coffee grounds make a good bug repellent. That is, spreading them around outside or lighting them on fire would effectively remove mosquitoes from your vicinity. Not that you should rub them on yourself. Though that wouldn’t smell half bad… Not knowing how my body might react to bug sprays and mosquito coils, I figured it might not be a bad thing to try.

I don’t drink coffee (never liked the flavour), so I mentioned it to a friend who does, with whom we sometimes camp. He agreed to save his coffee grounds when we camped next so we could try it out. Fast forward to last weekend. We were camping with this friend, and the first night, since we didn’t arrive until late, they had a bug coil out. The second evening, I mentioned the coffee grounds, but they were wet, so we put them into a disposable aluminum pan, filter and all, and set them by the fire to dry.

file0001364299685When they were only slightly damp, we started discussing how to make them do their thing. Note to self: If you want to do something while camping, remember to read up on how before you leave. We remembered they should be lit with a smidge of lighter fluid, but no one had any. One friend looked up another how-to online that said to sprinkle them around the campsite, but we decided to try the burning, despite having wet grounds and no lighter fluid. We stuck a tealight in the center, folded the edges of the coffee filter around the edges of it, and sat down to see what would happen. Unsurprisingly, the tealight burned. When the coffee filter dried out a bit more, it burned, with lots of smoke. When there was not much filter left, I piled coffee grounds around the wick. The coffee grounds never caught, but we did smell some coffee smells. Nobody got bitten by mosquitoes, but after a couple of hours had passed I asked, “Did anyone have any problems with mosquitoes *before* we did this thing?” Turns out no one had. “Ah well, we’ll try again tomorrow night.”

Mosquito (1)The next morning, we set the coffee grounds (and filter) out to dry in the sun early. All day long, through the 30 degree Celsius heat, they tried to dry. When dusk came, we were ready. We lit that bad boy up and…nothing. No burning. Tried the tealight again, and piled grounds all over the top of the candle. The wax melted and spread into the grounds. When the wick got low and the wax was diffuse, the grounds did seem to burn a bit, but maybe it was just the wax. Again, few people had any problems with mosquitoes, though I did get one or two small flying insect bites on my finger.

The verdict? Nobody pulled out the mosquito coil and demanded we upgrade. The friend says it seemed to work okay, but that further testing is needed. Maybe there just weren’t any mosquitoes around, and maybe it was a success. We’re considering making coffee ground and wax candles with wicks, considering sprinkling them around the site on the ground, and considering using dried grounds. I’ll let you know how it goes.

Have you tried this possible bug repellent method? What did you do? Was it effective for you? Comment below.

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