I guess you are right, if it were that potent at stopping spoiling we wouldn’t need all the chemicals we use today to preserve foods :D I’ll try cleaning the lemons more aggressively and see if it helps :D

Good to know, I’ll try again but will make sure the better clean the lemons!

Juice shouldn’t be the problem because the other half of my brew without the peel (but also with juice) worked without a problem. But good to know that the lemon itself should work, might be due to pesticide on the lemons…

Good to know it should work in general. I’ll try again :)

It was a very small amount of thinly sliced lemon peel (less than a teaspoon). From the other comments I’m guessing that the lemon was treated with a pesticide that also killed my fermentation.

Good to know, I’m going to blame the lemons I used and try again!

Thanks for your comment! Kefir might be more sensible to whatever treatment the lemons got, I guess I’ll try washing with hot water :)