How to Build a Kombucha Fruit Fly Trap

My Kombucha Seems to Be Attracting Hoards of Fruit Flies….. Help!

Fruit flies (or vinegar flies) LOVE kombucha. They can pop up and appear out of the blue, to hang around your kitchen relentlessly. No matter if your brewing tea batch is securely covered and there is no way that they can get into the brewing vessel, they will persist and persist. If you have any fruit in the vicinity, they will sometimes make that their base, while they wait endlessly.

Now I don’t know about you, but there is nothing more unappealing than bunches of fruit flies floating around in one’s kitchen. Really appetizing when you want to grab an apple from the fruit bowl, and end up sending dark clouds of fruit flies into the air! Ok maybe I am exaggerating a bit here, but you get my drift.

What To DO

My first thought was to rush out and buy an electric ‘tennis racket’, the ones designed to swat and electrocute mosquitoes flying in the air.

But, thankfully I discovered a simple, simple trick: A Kombucha Fruit Fly Trap. They are so quick and easy to make, I made mine in less than 4 minutes. There are two different ways, I like the first one because it has a cover, but the second one is even quicker to set up.

Kombucha Cone Fly Trap

What You Need

• 1 x jar, cup or glass
• 1 x piece of paper
• 1 x Stapler
• Small amount of kombucha

How to Make It

Take your piece of paper, and fashion it into a cone shape, with a small hole at the end. Use the stapler to staple the paper together to hold the cone shape.

Fill your container (jar, cup or glass) to about two fingers high with kombucha tea. Insert your paper cone.

Tip: Make sure that the hole at the bottom of the cone is close enough to the surface of the kombucha tea.
It must not be touching either, just a finger width or so away.

What happens is that the fruit flies follow the scent of the tempting kombucha, make their way down the cone, crawl through the hole to the kombucha, and then cannot escape again.

You might want to chuck out and renew the kombucha tea once a week or every few days. The kombucha usually starts forming a SCOBY on top, and some of the dead fruit flies end up being incorporated in it – very attractive for a kitchen counter display…

Kombucha Bowl Fly Trap

What You Need

• 1 x smallish bowl
• dishwashing liquid
• kombucha tea

How to Make It

Simply fill your bowl with some kombucha. Then add one or two small drops of dishwashing liquid. What this does is that the dishwashing liquid cuts the surface tension of the liquid, so that when the fruit flies / vinegar flies touch the liquid, they sink into it, and are trapped. Small insects like that can usually ‘walk on water’ because of water’s surface tension. However, adding soap to liquid reduces surface tension dramatically.

Word Of Fruit Fly Warning

Besides the fact that it is unpleasant to have fruit flies hovering around – as I so painstakingly pointed out above – it is also a good idea to lure them away from your brewing kombucha and trap them for the sake of your culture.

If given a chance, fruit flies can lay their eggs on the surface of your kombucha SCOBY. This is obviously not desirable, and besides being unhygienic and make you not want to consume your finished kombucha tea, can also be detrimental to the health of your SCOBY.

Be sure to always keep your brew safe by keeping the covering securely fastened over the top of your kombucha vessel, and make sure that you select a fabric which is dense enough to keep them from crawling through the covering itself. If you are using paper towel, it might be a good idea to switch to cloth, as the perforations have been known to allow the fruit flies through.

What To Do If Fruit Flies Get Into Your Brew

If somehow fruit flies have managed to crawl under your covering and get into the brewing vessel, remove the cover and make a close inspection of the surface of the SCOBY. If they have laid eggs on top of the SCOBY, then you might be able to see them with the naked eye.

If you can see any small white specs, these are the laid eggs. If you see small things crawling around, then the eggs have hatched and these are the larvae.

If the infestation is not that bad – say there are only a few flies, and you can also only see small amounts of white dots which you think are eggs, then you can try merely washing the culture with water. Keep in mind that tap water is not ideal for the kombucha SCOBY. For more on using the right water for kombucha have a look at What is the Best Water For Kombucha. If you only have access to tap water, check out the strategies you can implement it so that it can be used for kombucha in this articles What To Do If You Only Have Tap Water For Your Kombucha.

If you SCOBY culture is a few layers thick, then the best option is to peel the top layer off if you can. Sometimes it might be necessary to help the layer separate off by using a knife. If this is the case, be sure to use a stainless steel knife on the SCOBY. For in depth guidelines on how to separate and divide SCOBYs have a look at How To Cut A SCOBY In Half

Eww Factor Aside

Besides fruit flies hovering menacingly over your kombucha tea, and the sight of dead ones incorporated into your SCOBY, fruit fly infestations are also not the end of the world. If however the infestation is very bad, with lots of flies, and eggs having been laid on the SCOBY, then it might be necessary to throw out the batch, SCOBY, brew and all.

Kombucha tea from a batch which fruit flies have gotten into is still safe to drink but this is of course your personal choice. If you want to consume the brew, but have some misgivings, what you can do – after carefully removing your SCOBY to either wash or separate it – is to strain the batch through a fine strainer. Many people do this with all their batches to remove free floating yeast strands.