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accidental syrup fermentation Answered

I made some blackberry simple syrup the other day, and realized that it has started to ferment. I was baking bread around the same time, and it smells like bread yeast, so I imagine that's the culprit. It's currently in empty glass Izze bottle with a plastic bar stopper in my pantry, and is happily bubbling away.
My questions are:
How do I keep it fermenting? (does it need to be in dark/light, what are good temps, should I put a different stopper on it, how can you tell when it's done?)
Has anyone fermented with bread yeast, and how does that turn out?
Has anyone fermented syrup before? Does it make mead, or does it turn out more like liqueur?

Thanks for the interest, and hopefully this will turn into an instructable later! 


How did the syrup turn out? Update, please?

well, I guess I left it out a little too long, and it seems a little vinegar-y. But it's still super sweet, and so I just a little bit to salads and other recipes! The consistency is more fluid than it started out with, and the color pretty much remained the same. I did try fermenting another kind of syrup, (blueberry) but had difficulty getting that to start. It seems that you need your syrup to have no fruit pulp in it, and to be a slightly more watery simple syrup (1:1 sugar to water+ strained fruit puree instead of 2:1 sugar to water or similar) Unfortunately, school has taken over my life and I have not had time to make another batch, (Excuses excuses, I know), but as soon as I get a working recipe I'll post some more.

It morphed into a Salad Splash? That works for me. ;-)

thanks! I have moved it to a darker place, and have made sure the stopper won't explode while I track down an airlock. In answer to rafjr00, I didn't sanitize it, just cleaned it and ran it under the nearly boiling water that comes out of my tap. Next time (when I brew on purpose) I will definitely sanitize it. It's starting to smell like alcohol already (my roommate says it smells like 'church wine'- it's very fruity) although it doesn't seem to have stopped fermenting and there's no layer of yeast on the bottom yet.
I'm not sure if this will work with other types of syrup like rosemary or basil for example, (great for lemonade btw) so I'll make some more batches and try it with some wine yeast.
Eventually something amazing is going to come out of this, I just know it! When it does you all will get a top notch instructable, I promise. :D

I might be mistaken, but I don't think citrus-fruit-based wine/syrup will ferment.


6 years ago

Personally? i'd water it down a bit ad let that stuff go. nothing like homemade blackberry wine.

Try putting a latex balloon (or glove) over the mouth of the bottle and secure it with a rubber band. The set it in a cool, dark place... and wait.

Low-rent homemade wine is made this way.

Sounds like a fun and interesting project!

...realizing it will only ferment until the concentration of alcohol starts killing off the yeast. That alcohol is actually the "waste product:" of the growing yeast.

Sunlight will spoil your colour, but just vent it.


You should get some kind of air lock, check your local brew shop, if you have one.. If it is bread yeast, you will not get a very high ABV. Alcohol kills yeast, different yeast can handle different amounts. Just remember, there is nothing in there that can kill you. Might not taste or smell great, but it won't send you to the hospital.

You did sanitize the bottle first? It is not "strictly" required, but if you are not storing it in the fridge it is good practice.

+1 to above.

The best temperature to keep it is "warm" (approaching body temperature if you can. I don't think light levels make a difference to fermentation, but they might encourage other micro-organisms you have accidentally included, so I'd go with "dark".

(And don't forget the airlock Rafjr00 suggested, otherwise gas pressure will shoot stoppers and syrup all over the place.)

Usually light is not a big deal during fermentation, don't sit it in the sun though. But with not knowing which bug is having the fun I would try to keep it in a dark and cool place, under 80F but above 70F. Bet it goes well with some rum and 7 when it is done. Give a day or two after it stops bubbling like crazy then give it a taste.