I don’t know about you guys, but I’ve (finally) started paging through my favorite seed catalogs, thinking about seeds, planting and the soil in which I grow my food. I live in South Philly, so the vast majority of my gardening is done in containers, and as my favorite gardening guru said (or perhaps wrote in one of her books), for all intents and purposes, the soil is the garden.
Beyond growing the living things that we, eventually, eat, soil is actually teeming with life that goes well beyond earthworms. Tons of bacteria, from C. botulinum to our lactic acid friends, make their homes there as well. Things that grow in the soil (aka plants) are covered in a wide variety of bacteria as a result. You can read more about how to help the good bacteria thrive after being plucked from the earth here.
Since those bacteria start in the soil, they are primarily present on the peels or skins of the vegetables. I took a big ol’ class with Sandor Katz last summer and one of the (many) things I asked in the class was whether or not it is true that the bacteria lived pretty much exclusively on the peels. Katz confirmed that it was, and made a fun analogy that has stuck with me. He compared the bacteria on the peels of vegetables to the bacteria on our skin and throughout our digestive tract (from mouth to intestines). Other than that, our bodies are generally free from bacterial life. Since vegetables don’t have a digestive tract, the bacteria with which they co-exist inhabit their skins, almost exclusively.
I’ve done side-by-side trials of vegetables with and without their peels. Vegetables without peels have either not fermented at all or have fermented excruciatingly slowly, which is generally not something that makes me want to grab my pickle fork and chow down. We want the lactic acid bacteria to be active and thriving, because they are precisely what makes these foods safe (not to mention gleek-inducing) to eat.
A few exceptions: for some reason, onions do absolutely fine without their peels. I suspect that it’s the way they grow in layers, and that some bacteria are present many layers deep, but I have no scientific knowledge to support or refute that. I also peel garlic, but garlic isn’t the most vigorous fermenter. It is most often used as a seasoning, mixed in with other fermented vegetables, so it’s not too surprising that it’s not an issue to always peel it.
I always leave the skins on beets, turnips, carrots, rutabaga and right down the line. I do peel hard, winter squashes with unappetizing or inedible peels, but I always include some of the peel in the ferment, and all is well. Most importantly, remove any bits you hate. I always trim the crowns and sometimes the root bits, but I keep most of the peel in tact.
So. Have you fermented vegetables without their peels? How did it go?
Doreen says
What about washing them? I assume it’s not a good idea to scrub them either.
Amanda says
Definitely wash them as you would normally wash vegetables for cooking. Vegetable “washes” and hot water are not recommended, though. Either could potentially kill the good bacteria.
Marybeth says
I peel burdock root when I ferment it with carrots. But the carrots are not peeled.
Amanda says
I can see why. I get a lot of literally gnarly burdock!
Becky says
One of the things I like about fermenting is that I can be so lazy in my prep, so no, I don’t peel.
Amanda says
A woman after my own (lazy) heart :-).
Kris says
Fascinating and sensible. Thanks for the post!
Amanda says
Thanks for reading, Kris!
Francoise Murat says
I’m too busy and basically too lazy to peel most things! But mostly because my Grandma used to just wash and scrub a bit and use as is. I was always told that most vitamins and minerals are in the skins of veggies – I garden organically so feel very confident in what I ingest and also to be honest I was brought up to think that a bit of dirt always immunised you! I perhaps wouldn’t stick what that nowadays 🙂 Great post, have just sent your link to a friend in Geneva (that Geneva posse is growing!)
Jess says
If I want to peel my carrots for fermenting can I just put a handful of the peels at the bottom of the jar with the garlic?
Amanda says
Yup! When I have inedible peels, I peel first and include the peel for fermentation.
anne says
I wash my veggies with a bit of vinegar and water to get off any pesticides as I can’t alway get organic and even when I can I am concerned about all the handling vegetable go through in the store. Does this kill the good bacteria? I don’t peel.
Amanda says
Hi Anne,
It’s probably fine. A good rinse in cool tap water would probably be a bit better (there’s at least one study that indicates fermentation eliminates pesticides (that’s not definitive, but it is interesting).
A. Heino says
I sometimes peel, sometimes not. Results are quite close to the same, about 5-7 days for
most veggies to reach the desired 3.3 pH in the brine. I’ve been fermenting turnips now for 5 days, the pH is at 3,9, salt percentage is at 2,5%. A few aren’t fully submerged, but there is no slime or mold. Just carbonation bubbles and a strong funky odor. I assume the odor to come from the sulfites present naturally in the turnips. Do you have similar funky odor experiences with turnips?
Amanda says
Our experiences differ substantially, but that’s always cool to know! Peeled/unpeeled side-by-side batches have resulted in dramatically different batches. Times to reach pH below 4.0 (in the few batches I measured that way) in addition to flavor, surface issues, etc. Plus peeling is much more work and I don’t like removing nutrients when I remove the peel.
I personally love the aroma of fermenting turnips, so I guess I can’t say that I do have the same experience there either. But I also don’t measure pH or weigh salt unless I’m testing a recipe or a technique, so it does sounds like our preferences in general might differ.
Sounds like you’ve got things down to the way you like them! That’s wonderful.