Flies and Fermenting

You’ve heard the old saying “You can catch more flies with honey than with vinegar,” right? If you’ve brewed kombucha, you know that it isn’t true!

In nature, vinegar (acetic acid) indicates fermenting activity, which signals to scavengers like flies that there’s a bounty of rotting food nearby (Yummmmmy)! Because fermentation is really just controlled decomposition (don’t tell your non-fermenting friends, it might gross them out), flies are naturally drawn to most fermenting foods.

The usual precaution is to cover any ferment with a cloth (cheese cloth is not recommended because the critters can shimmy through it) and secured with a rubber band or string to keep the cover taut.

Kombucha in particular can be problematic with fruit or vinegar flies due to its strong odor. Fortunately there are some great homespun fly traps you can make.

How have you dealt with vinegar flies? Please share!

Homemade fly trap

Homemade flytrap made from over-ripe kombucha

6 thoughts on “Flies and Fermenting

  1. Againstthegrain

    If I have an abundance of ripening fruit on my counter sometimes fruit flies/vinegar flies (i.e., drosophila) set up camp, so I set out a vinegar fly trap (or two, or three). To a very small jar or glass I add about half inch or so of apple cider vinegar (kombucha would work, too). Then I tape a piece of paper into a cone shape, leaving the tip slightly open (or the tip could be cut off, but keep the opening NO larger than 1/8″). The cone is placed on the jar or glass like a lid, with the cone pointed down inside the jar. If I place the jar in a good spot, the aroma of the vinegar attracts the flies more than the fruit does. The fruit flies go into jar for the vinegar, but then they can’t make their way back out very well (yes, eventually they drown in the vinegar, but I don’t lose sleep over that, frankly). Rinse and replenish the vinegar as needed.

    Note that these traps don’t work at all with houseflies.

  2. Againstthegrain

    I should have also mentioned that the tip of the cone shouldn’t touch the vinegar. So proportion the cone length and vinegar level so they don’t meet.

  3. Austin Post author

    Great tips. Thank you for giving us your solution!

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