Place the blueberries into a wide-mouth pint-sized mason jar, leaving an inch or so of space at the top of the jar. Add enough honey to cover the blueberries completely. Make sure the blueberries are coated with honey. The blueberries will float, but that is ok.
Place the lid on the jar loosely, then tuck it into a dark place.
Every day or so, tighten the lid on the jar and flip it upside down to coat the blueberries with honey. Loosen the lid again when you return it to the upright position.
Within a few days to a week, you may start seeing small bubbles start to form on the surface of the honey.
The blueberry honey will ferment for about a month, but you can eat it at any time. The flavor will continue to develop over time, the blueberries will shrivel a bit, and the honey will become much runnier and will be pink or purple in color.
Store the fermented blueberry honey in a cool place for many months or even a year, if not longer.
Notes
It’s important to use raw honey for this recipe, as it has all of the bacteria and wild yeast that are necessary for fermentation.
The small amount of juice from the blueberries will create just enough liquid for fermentation to happen.
It’s a good idea to put a plate underneath the jar during fermentation, as it may bubble up, and a little bit of honey could possibly drip out.
If you are concerned about botulism, use a pH test strip. Botulism spores can't reproduce with a pH of less than 4.6. Honey is usually around 3.9, but that can vary between brands.
If the pH is too high, add a splash of raw apple cider vinegar to add more acidity and retest. This is generally not needed, but I do want to mention it.
Blueberry honey should not be given to babies under one year of age.