Fruit Flies and Sourdough Starter (Tips on how to manage them)

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Fruit flies in a sourdough starter is never a great way to start the day! Fruit flies can be drawn to the smell and taste of sourdough. Though this creates an unintentional fruit fly trap, it can create new challenges when going to make a recipe. Learn how to navigate fruit flies and sourdough in a few easy steps.

Nothing is worse than being excited to make a recipe, only to find your sourdough starter had unexpected visitors (aka fruit flies). These visitors are of my least favorite bugs – right up there with mosquitoes, flies and spiders.

Unfortunately, with warmer weather – it often comes with fruit flies in the kitchen. And man, can fruit flies create additional challenges in your kitchen when trying to maintain a sourdough starter!

There are a few reasons fruit flies like sourdough starter from the smell and the texture. And while we do not want to create an unintentional fruit fly trap – there are plenty of things we can do to keep our sourdough starter ‘safe’ and free of bugs.

This article will explore why fruit flies like sourdough, how to prevent fruit flies, tools to keep fruit flies from getting into sourdough starter and when to throw out sourdough starter (and just start over.).

It is a pleasure to share about sourdough on my blog to help you learn more tips and tricks. I hope these help you on your sourdough education journey!

Why fruit flies like sourdough starter

Fruit flies can be attracted to a sourdough starter because of the smell. When your sourdough starter is ready, it will smell sweet and yeasty. It will have a pleasant aroma and texture.

Fruit flies are drawn to sweet smells and fermentation. They like the smell of fruit, sourdough starter, kombucha, apple cider, wine, and even ginger bugs! Unfortunately, they can accidentally mix up fruit and fermented products.

When the weather is warm, it can cause challenges for sourdough starter – especially because the speed of fermentation can be impacted (and also by the addition of fruit flies)!

How to prevent fruit flies from getting into sourdough starter

There are many options you can do to prevent fruit flies from getting into your sourdough starter. Start with the basics – ensuring you have a clean sourdough jar and a proper way to maintain your sourdough starter.

Some people find storing the sourdough starter in an enclosed location, like the fridge can be helpful to prevent fruit flies from entering.

Tools to prevent fruit flies from getting into your sourdough starter

• Cover with a lid fit for your sourdough jar (on top but not closed too tight – the gas bubbles need room to expand with fermentation)
• Cover with a towel and ‘seal’ with a rubber band
• Cover with a nut milk bag and synch it tight. I like to put the cord around my sourdough jar for an extra barrier.
• Place your starter in an enclosed environment – IE a cupboard, microwave, oven
  • Just be sure not to turn it on when your starter is inside.
• Store your starter in the fridge
• Store it away from the kitchen (in another room)

Kitchen maintenance to reduce fruit flies

• Use a fruit fly / pest spray
  • Be sure to ensure it is safe for use within the home and that your sourdough starter is no where closer. Chemicals and sourdough starter do not mix.
• Make a homemade ‘fruit fly catcher’ and place it by your sourdough starter.
  • We like to put apple cider vinegar (or balsamic vinegar) and some dish soap on top next to our starter. This can attract them to a different smell and make sure they stay away from the starter.
    • The vinegar smells good to the fruit flies and the dish soap will prevent them from escaping.
• Purchase a flying insect trap – like Zevo
• Put your fruit away in the fridge
• Take out your trash and compost regularly which could cause fruit flies to become attracted to the smell.
• Ensure the fruit flies are not breeding in your kitchen sink. Sometimes, they get stuck in the hot water trap and lay eggs. If you pour vinegar and hot (not boiling) water down your drain, this can help to reduce the eggs.

When to throw out sourdough starter

There are multiple reasons to throw out sourdough starter and start from scratch. This can be due to the acidity level, mold in the starter, broken glass in the starter, a sluggish starter or even bugs in the starter (like weevil bugs).

It is up to your judgment on whether or not you need to throw out your starter and make a new one. As a general rule of thumb, if it smells off – looks off or just does not seem safe to use, use your discretion!

Fruit flies can be harmless – but they can also multiply. And quickly.

If you have ever had a fruit fly ‘infestation’, you will know how quickly they seem to appear out of no where. They contaminate things quickly and sourdough starter can be one of them.

In my opinion, I would much rather make a new sourdough starter than cause my family (or others) harm from my baked goods being contaminated.

Learning how to begin a sourdough starter from scratch is important – especially if you do not have access to buying a dehydrated starter.

I always recommend having a backup sourdough starter handy – just in case something happens and you need to start over again. We have saved sourdough in the freezer and also dried sourdough starter to ensure we have a back up – because you never know what will happen.

Of course you can always share a sourdough starter with a friend, too. Nothing is better than sharing sourdough with others!

Have you ever experienced fruit flies in the kitchen? If so, have they gotten into your sourdough starter? Let us know how you handle them in the comments below!