Fermented Wild Plums!

This is a method rather than a recipe, so the notes are going to be very, very detailed. Even compared to usual.

This is a weird sort of deal for me, because I already decided not to forage this year unless it was “necessary.” I have an incredibly severe reaction to ragweed (contact too, not just pollen!), and it happens to me often enough that I understand that with that particular issue, this isn’t a good year to risk getting as sick as I sometimes do from ragweed.

But…

…these plums were screaming at me to gather them. As I was leaving a friend’s neighborhood where I was dropping some stuff for her, I saw that the wild plum trees (Prunus mexicana) in the median were dropping plums like it was… well, the end of the season, I guess (it is!). I parked, of course, grabbed a bag, and went to see what could be seen. There were so many plums dropping that I ultimately decided not only to only take from one tree, but also to only take what it’d just dropped. After about 15 minutes of sorting good and bad plums off the ground, I had around a gallon of them. That seemed like plenty for me, so I went ahead and left since I knew I didn’t need them for mead this year. I’ve used plums from this specific tree before to make mead, but I really don’t have space to store more filled carboys right now.

Anyway, I gathered them, and didn’t get poisoned in the process (because none of the ragweed was right there)! Win-win!

If you are actually going to gather your plums out in the world rather than buy them at the store and you’re going the short people/lazy route by not picking them off the tree, the sorting process is fairly simple: leave the ones that are darkened, bruised, or soft on the ground. Those ones are for the bugs and other animals; you keep to the red ones. Red ones, you say? Yes! The red ones! These will have a greyish purple sort of layer over the red, and that is yeast. So that’s okay and is what we want right now. But yeah these plums are a kind of bright red color (I’m bad at nuanced color words, sorry).

Your plums should be firm and can have a bit of give when you gently press on it. So, exactly like when you buy plums at the store. You’re just grabbing them from the ground (or the tree) instead of bins in the produce section. These guys really are tiny.

I really should have saved a plum to take a picture, but I forgot. Then I remembered that my favorite forager, Merriwether, has a picture on his site. I linked this site above too, for those of you who are seeking more/new info on foraging skills. He’s also got information in this link on how to use plums to make a new sourdough starter, so y’all read that too!

When I got them home, I really did mean to deal with them that night. And the next. And the next. And then still one more. I finally remembered that fruit rots whether you’re ready to use it up or not, so I sorted them. I lost about a pint or so to excessive softening, and happily didn’t see any moldy ones after such a long wait!

But what to do with them? I knew I was going to make a small amount of jam, but I had more than a small amount of plums still. Fermented plums it is! I made 2 jars of brined plums, and then tucked the last of them into the freezer to make a not-right-now jam. These plums are fermenting whole, but you can remove the stones and cut them up if you like. I didn’t like because it was too much work in the moment and because these plums are marble sized so I think they’re cuter in there whole.

The method I used for these is exactly the same, and you should feel free to explore your spice cabinet to see if there are combinations you might really enjoy trying. Accordingly, as with an awful lot of my recipes, this should be really easy to customize to the preferred flavors in your home! I’m also not giving y’all quantities, because in lacto-fermenting it’s the ratios that matter rather than a set amount.

One last note: when you’re getting into your fermented plums, don’t use your hands. We all want to just pluck out the most delicious looking ones from the jar, but if you do that you’re risking introducing stuff to the jar you didn’t want in there. Use a clean utensil every time. Yes, you need a new spoon if you licked yours and still want more plums afterward.

Here’s what you’ll need

Plums! How much is up to you and how many jars you want to fill

Salt: I use 3/4 teaspoon per cup of water

Water (determined by the size of your container and how full it is)

Spices, if desired. Some excellent options for plums are allspice, mint, cardamom, saffron, mace or nutmeg, black pepper, thyme (go easy on this one), rosemary (ditto), vanilla bean, splash of bourbon, rye flour or sourdough (this is a thing in some fermented Russian plums), lemon verbena, lemon, sage, cinnamon, goldenrod leaf is really nice with plums (you can use flowers too, but it’s rude to the bees since this is one of their last sources of nectar for the year), basil, turmeric, anise or star anise, chrysanthemum flowers, and clove. Sky is really the limit here, but these are the flavors that come to my mind when I think of plums. You should pick the flavors that come to your mind when you think of plums!

In mine, I used 3 cardamom pods, a good sized slice of ginger (it was around 2” diameter and probably half an inch thick), and 3 black peppercorns to flavor my 1L jar (this was a bit under 2 cups of water for me). I used no spices at all in my 1.5L jar, but did add half a cup of honey.

Spices on the left, honey on the right.

Here’s what you’ll do

The first thing you should do is rinse your plums well. Don’t wash them - you want that yeast! But you don’t want whatever bird poop, bugs, grass, or other schmutz is on them. Actually, just don’t take the ones with bird poop (yes, I have put plums back on the ground when that was part of their deal), but rinse what you take well anyway.

After that, add spices, if using, then put the plums in your jars or crocks! If you’re using a fermenting jar, like Fido or Kilner, you don’t need to weigh these down to keep them submerged. If you don’t, you do. I pack them in pretty tightly without being rough with the plums, since I don’t want them crushed. Add a weight at this point, if you need one.

How I do the water these days is kind of inefficient, because I’m trying to not have a random jar of leftover brine I need to figure out what it’s going to be used for (or store for later) laying about. But if you don’t mind doing so, you can make up a big batch of brine for fruit and store your leftovers until you’re ready for them.

What I do is put around 3/4 teaspoon of whichever non-iodized fine salt was closest to my hands (use a teaspoon if kosher salt) in a cup of warm water and then I whisk it to combine. I’ve seen people do lacto-fermented fruit with a 1/2 teaspoon per cup of water ratio, and that’s also fine for those of you who prefer lower salt amounts in your recipe. Also people do more, a teaspoon or so. So you’ve got some float here, but somewhere in that .5-1 teaspoon range is what we’re looking for. Where you are in that range is all about personal preference.

I don’t let it cool off before I pour it in the jar, because my life is chaotic and I’ll forget to put it in there for hours, but can cool it first if you want to. You can also use hot or boiling water if you really are going to let it cool first.

Either way, once you’ve got your brine done, put it in, and then make more if you need more.

Fermenting jars:

You need to leave an inch or two of headspace in your jar. I generally mark the spot at the “shoulder” of the jar. Once your jar is full, close it, then stick it somewhere dark with a plate or bowl under it. If you didn’t leave enough headroom, you aren’t going to want to clean that mess up when pink brine gets all over when it self-vents. Once you’ve opened these jars, you do need to fridge them because they’re now at risk of mold.

Any other container that doesn’t hermetically seal:

You should also leave headspace. Ferment means “to boil” for a reason; it can get crazy in there and the messes are real! You also must weigh your fruits down so they’re completely submerged under the brine. Otherwise, you’re going to make some moldy was-food instead of a new food, and that defeats the purpose of gathering, picking, or buying fresh plums. In an ideal situation, your brine will also completely cover the weight.

You should, but do not have to, use some kind of lid. It can be Saran wrap (what I’m currently using on my crock of half-sours), an actual lid (usually the one that came with the container), a napkin, last Sunday’s paper, whatever covers it. You’re just trying to keep out bugs, dust, and debris here. I use Saran wrap because it’s less likely to result in fruit flies and gnats in your home than the more porous options are. Gardeners and fermenters are constantly battling that little problem, and since I’m both this matters a lot to me.

And now you wait! You can eat these as early as a few days to a week in, or you can age them longer. I plan to sample them periodically and enjoy the ways their flavors change over time (mine will change more slowly once they’ve been opened, because they’ll change in the fridge). You do not need to fridge these once opened if you’re not using a fermenting jar, because all you have to do to prevent mold is put the weights back on so the rest are still submerged. And cover it again, of course. You may, of course, fridge them if you like to, and you should fridge them when they taste perfect to you. Leave them out, they may not taste as perfect once they’re more fermented.