Along the Grapevine

Fermented Unripe Blueberries


If you have been following this blog lately, you will have noticed that I have started to ferment many of my wild edibles from the garden. It is my new favourite method for preserving most of my harvest, and for using as a base for some interesting dishes. I mentioned that I had bought some air locks which I intended to use. My usual method is simply to pour a brine over whatever (e.g. vegetables, cucumbers, ramps) with whatever flavourings and spices I feel like using, weigh them down to keep them submerged, cover with a paper towel or cheesecloth to keep the bugs out, and that is it. Just wait a few days until the taste is right, put a lid on it and into the fridge. I have also used whey instead of the brine, but I seem to be favouring the brine method. I did promise that once I figured out the airlock, I would share it.

The one fermentation I have done with the airlock is with green blueberries instead of wild unripe grapes, which I would have used had I had any. Having shown up rather late to the blueberry picking, I found mostly green berries on the bushes, so decided I would have to figure out something to do with them. My first experiment was with my version of verjus, which has been an excellent substitute for vinegar in salad dressings. Those which remained, I fermented.


The airlock is the same that is used in making beer or wine, and can be purchased wherever supplies for this are sold for between $2-3. The idea is that it allows carbon dioxide to escape while not letting any air in. You will need a bung, or rubber stopper as well as the airlock. The stopper looks like a cork with a hole through it. The airlock is fitted into the hole once the outer part is filled with water up to a line, the inner part place over the middle tube. The lid has small holes in it to let the carbon dioxide escape. Here’s what it all looks like.



I filled a sterilized jar about 3/4 full with blueberries, covered it with the brine – made from 2 Tbsp salt per 1 quart of non-chlorinated water. I carved a hole in the lid in which to fit the bung, set the airlock in and left it for about 10 days – until lots of bubbles formed on top. The time will vary depending on the temperature of your kitchen, but ideally this should be not above 75 degrees F. ย Then I put a regular lid on it, and put it in the fridge.

To try these probiotic-rich berries, I decided to add them to a salad made with what I had in the garden, which this week is beans and potatoes.



I blanched the beans, boiled and peeled some blue potatoes (any colour of potato will work but I wanted to stick with the blue and green theme I had going), a mustard and garlic vinaigrette, and my fermented blueberries. By mistake, I added salt to the dressing, and thought maybe with the salty berries it would be too much, but as it happens the blueberries did not taste that salty, and the seasoning was just right.ย DSC01168

These would be good with just about any salad, but I would like to try them with fish, and possibly in a sandwich filling. This same method can be used with most other berries, though not strawberries. I could even be done with actual blueberries! but it was a great way to use the unripe ones.


Author: Hilda

I am a backyard forager who likes to share recipes using the wild edibles of our area.

20 thoughts on “Fermented Unripe Blueberries

  1. Very cool, Hilda! I’m sure the flavours are just amazing here! I sure love the colours. I had never thought of fermenting blueberries, but then again your blog always seems to be introducing me to new ideas! I just love it.


  2. How cool and interesting is that Hilda. You are always teaching something new to me.


  3. This is so informative, Hilda. Thanks for sharing!


  4. What do the blueberries taste like when you finish the process?


  5. What a fantastic idea! Thanks for sharing!


  6. Loving that! Always wondered why you needed the airlock I have a bucket of grapes fermenting right now must go get an airlock !


  7. What a lovely looking salad.


  8. Wow! I know I always write the same in my comments to your posts – never heard of this plant, never tried this variety, never would have had this idea. But it’s always true, like this time again: What a great idea to have a recipe for unripe blueberries! Seems that they can be used like capers? I guess I will try this next year.


    • Thanks Claudia for the kind comments. I am trying to expand my own repertoire in cooking, and am happy when I can introduce others to my own efforts. And yes, they are like capers. Although I have so many ersatz capers already in my fridge e.g. fermented mallow pods, dandelion buds, I hadn’t thought of them like capers, but they are. Which makes me think they would be good on pizza!


  9. My nieces and nephews call blueberries “bloobs” – while I doubt I could sell them on some fermented bloobs, I’d certainly be happy to try them! Love your homemade fermenter, by the way!


  10. This is inspiring, Hilda. I like how you make use of what you have in your garden, and this is a great example.


  11. This is pretty ingenious! And your salad is absolutely BEAUTIFUL.


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