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Fermenting & Root Cellaring

Two old methods that need almost no equipment: lacto-fermentation turns sugars into preservative acids and gases (kraut, kimchi, sour pickles), and root cellaring holds whole vegetables in cold, humid storage through the Canadian winter.

How it works

Lacto-fermentation uses naturally occurring lactic acid bacteria in a salt brine (usually 2 % by weight) to outcompete spoilage organisms. Root cellaring just exploits a cold, humid space — historically a Canadian winter staple.

When to use this method

Ferment: cabbage (kraut), cucumbers (sour pickles), carrots, beets, radish, kimchi vegetables, hot sauce. Root-cellar: potatoes, carrots, beets, turnips, parsnips, onions, garlic, winter squash, apples, cabbage.

Authority sources

Two old methods, one page

Lacto-fermentation and root cellaring are different techniques but share a goal: preserving food without heat, pressure, or electricity. They're how Canadians fed themselves through winter for centuries before refrigeration, and both work better than most people expect.

Lacto-fermentation uses naturally-occurring lactic acid bacteria in a salt brine. The salt steers which species get going. The bacteria convert sugars in the vegetable into lactic acid, which preserves the food and adds tang. Sauerkraut, kimchi, sour pickles, and fermented hot sauces work this way.

Root cellaring exploits the natural cold and humidity of a basement, an insulated outbuilding, or — historically — a hole in the ground. Whole, undamaged vegetables (potatoes, carrots, beets, turnips, cabbage) keep for 3–6 months at 0–5 °C and 85–95% relative humidity. Winter squash is the exception and wants a warmer, drier spot — see the crop table below.

Corrected 19 September 2026: this paragraph used to list squash among the vegetables that keep at 0–5 °C, which contradicted this page's own crop table below. Alberta Agriculture puts winter squash at 10–12 °C and dry, and OMAFRA's chilling-injury table records pitting, poor flavour and increased rot in winter squash and pumpkin held below about 10 °C. Squash you stored in a cold room may have suffered on quality; nothing about it becomes unsafe, and there is nothing to discard.

New to fermenting? Start here

If you've never fermented anything, the order that works for most Canadian home fermenters:

  1. Sauerkraut — one head of cabbage, 2% salt, no specialty equipment. The gateway, and the one vegetable on this list BCCDC publishes a salt range for.
  2. Lacto-fermented carrots — kid-friendly, fast (1–3 weeks), almost impossible to mess up.
  3. Fermented salsa — August tomato project. Builds on the sauerkraut technique with mixed vegetables.
  4. Fermented hot sauce — August/September pepper project. Adds the "blend with vinegar" finishing step.
  5. Kimchi — once you've done kraut twice, kimchi is the same technique with paste.
  6. Ginger bug or water kefir — entry to fermented beverages.
  7. Kombucha — once you've kept a ginger bug alive for a month, kombucha's SCOBY maintenance is the same rhythm.

The progression takes most fermenters 3 to 6 months. The skills compound — by month six you can ferment almost anything without a recipe.

Lacto-fermentation: what the salt does, and what makes it safe

Salt steers the ferment. The acid the ferment produces is what makes the food safe. The BC Centre for Disease Control puts it in those terms. Salt concentration is a critical control point "to drive the primary fermentation towards specific species of LAB groups", and the acid is the one they call main — "log sheets of pH verifications are kept and monitored as this is the main CCP." Their finished-product target is pH 4.6 or lower, and a batch that has not reached it within a week is one they say to discard. That check needs a calibrated meter or strips and is written for commercial operators; no Canadian authority we could find publishes a home version of it.

The salt figure belongs to the vegetable, and it is not one number. BCCDC's Table 3 names three: cabbage at 1 to 3% (2.25% optimal), carrots at 5% alongside a commercial lye wash, cucumbers at 3 to 15% depending on the pickle. Until September 2026 this page gave around 2% for cabbage, cucumber, carrot, beet and radish together. Two of those five are contradicted by the table above and three have no published figure at all, so the sentence is gone. Where a recipe on this site gives a figure BCCDC does not publish, that page says the figure is ours.

To work the salt out from a percentage your recipe gives you:

  • Weigh the vegetable plus the water in grams.
  • Multiply by 0.02 to get grams of salt.
  • Example: 800 g of cabbage + 200 g of water = 1,000 g total. Salt = 20 g (about 1 tablespoon).

Use non-iodized salt — iodized salt inhibits the bacteria you want. Pickling salt, kosher salt, or sea salt all work.

For cabbage, 2% sits inside BCCDC's published 1-to-3% band and is our pick within it. For cucumbers, see the sour pickle guide, which uses 3.5% and says why kraut figures do not transfer. Every other vegetable on this site carries a figure that is ours, labelled as ours on its own page.

Equipment for lacto-fermentation

  • A jar or fermentation crock. A 1 L mason jar works for small batches. Specialty fermentation crocks (water-sealed ceramic) are a nice upgrade for larger batches — they vent CO2 without letting air in.
  • A weight to keep vegetables submerged below the brine. Specialty glass fermentation weights, or improvise with a sealed water-filled zip bag, or a small clean rock in a food-safe bag.
  • An airlock (optional) — lets CO2 escape during active fermentation without letting air in. Worth it for batches over 1 L.
  • Non-iodized salt.
  • A kitchen scale — every salt percentage depends on weighing accurately.

See our Canadian preserving equipment guides for crocks, jars, and tools compared.

The lacto-fermentation process

  1. Weigh and prep vegetables. Shred cabbage for kraut; slice or quarter cucumbers for pickles.
  2. Calculate the salt at 2% of total vegetable + water weight. Mix the salt into the vegetable (for kraut: massage until liquid releases) or dissolve in the water (for whole pickles in brine).
  3. Pack into the jar, pressing down so the brine covers everything.
  4. Weight the vegetables down below the brine. Any vegetable that floats above the brine line will mould.
  5. Cover loosely (or airlock if you have one). CO2 needs to escape.
  6. Leave at room temperature (18–22 °C) for 5–14 days. Active fermentation looks bubbly the first 3–5 days.
  7. Taste daily after day 5. Move to the fridge when it's as tangy as you like.

Refrigerated, lacto-fermented vegetables keep 6–12 months. They keep getting tangier in the fridge but at a much slower rate. This window is ours. BC’s Centre for Disease Control covers fermented vegetables and deliberately sets no keeping time — it leaves shelf life to the producer’s own determination, in guidance written for commercial operators rather than home kitchens. Past our window, Québec’s rule applies: “When in doubt, throw it out!”

Fermented beverages: kefir, kombucha, ginger bug

Three Canadian-home approaches to brewing probiotic sodas at home — each uses a different culture but follows the same general principle of feeding microbes sugar water and bottling for fizz.

  • Water kefir — uses crystal-like "water kefir grains" (tibicos) to ferment sugar water in 24–48 hours. Dairy-free, mild, easy maintenance. Best for daily-drink households.
  • Kombucha — uses a SCOBY (symbiotic culture of bacteria and yeast) to ferment sweet tea over 7–14 days. Stronger flavour, longer cycle, fits a weekly-batch rhythm. Continuous-brew once you're set up.
  • Ginger bug — wild fermentation from organic ginger. No purchased culture. Used to carbonate any sweetened liquid — ginger ale, root beer, lemon soda, herbal tonics. Traditional and flexible.

All three produce alcohol as they ferment, and a home batch does not measure how much. Federal regulations require 1.1% or less alcohol in a non-alcoholic beverage; the BC Centre for Disease Control records that water kefir is well documented to contain elevated alcohol, and recommends the precautionary statement “may contain alcohol. Not a suitable beverage for young children or during pregnancy.”

Common lacto-fermentation failures

  • White film on the brine (kahm yeast). Harmless but indicates poor seal or too-warm room. Skim it off; tighten the lid; move to a cooler spot. Kraut underneath is usually fine.
  • Pink, blue, green, or fuzzy mould. Discard the whole jar without tasting. This is bacterial contamination, not benign yeast.
  • Soft pickles. Old vegetables (cucumbers more than 24 hours from picking lose firmness), too-warm fermentation, or no tannin source. Traditional fix: add a fresh grape leaf, oak leaf, or black tea bag — they contain tannins that keep pickles crisp.
  • Off smell (rotten, not tangy). Discard. Healthy lacto-fermentation smells sour, like sauerkraut juice — not putrid.
  • No bubbles after 5 days. Salt too high, temperature too low, or vegetables already pasteurized (you used canned or blanched veggies by mistake). Restart with fresh ingredients.

Root cellaring conditions

Our root cellaring guide carries the fuller crop-by-crop version of this, sourced to Alberta Agriculture and OMAFRA. The textbook root cellar holds 0–5 °C and 85–95% relative humidity. A few practical Canadian options:

  • A cold-room in a basement — uninsulated against the outside wall of a basement, ideally with a small vent to outside air. Most Canadian homes built before 1970 have one.
  • A second fridge set to 1–4 °C — works well for the cold side; humidity needs a tray of water inside.
  • An attached garage — works in deep winter (0–5 °C reliable) but freezes in February and gets too warm by April. Only useful for short-term storage.
  • A buried bin or "root pit" — old-school but effective. A clean trash bin buried below the frost line, packed with vegetables in damp sand, covered with insulating straw.

The wrong conditions: dry, warm basements (most modern Canadian homes with conditioned basements) — vegetables shrivel and sprout fast. Garages with fluctuating temperatures (warm days, freezing nights) — vegetables freeze-thaw and turn mushy.

Storage by vegetable

Periods, temperatures and humidities here are Alberta Agriculture’s Home Vegetable Storage, Agdex 732-15, Table 1. They are how long a crop holds its quality — Alberta says nothing about anything becoming unsafe.

  • Potatoes (table) — 5–10 months at 5–7 °C, 90–95% humidity, in the dark. Colder is not better: Alberta puts the ideal at 5 to 8 °C, and sprouting comes on warmer than that.
  • Carrots, beets, turnips — 4–6 months at 0–1 °C and 95% humidity, in damp sand or peat. Stored loose in a fridge, 2–3 months.
  • Parsnips — 2–5 months, the same cool and humid conditions. Shorter than the other roots, which is why they are not on the line above.
  • Cabbage — 2–6 months at 0–1 °C, hung by the stem or wrapped in newspaper.
  • Onions (cured) — 4–8 months at 0–3 °C in a dry spot (70–75% humidity). Different from root vegetables; too humid and they rot.
  • Winter squash — 4–6 months at 10–12 °C (warmer than root crops) and dry. A spare bedroom works. Pumpkins are 2–4 months in the same conditions — Alberta lists them separately and shorter, so do not plan a pumpkin like a squash.
  • Apples — Alberta gives no window, only an upper bound: up to 12 months, highly variety dependent, at 0–1 °C and 90–95% humidity. Store away from other vegetables — apples release ethylene, which accelerates ripening on everything nearby.
  • Garlic, kohlrabi, rutabaga — not in Alberta's table, so we give no period for them. They are stored the way their neighbours above are; how long they hold is not something we can cite.

What needs to be perfect going in

Root cellaring rewards careful selection. Damaged vegetables rot, and one rotting vegetable spoils its neighbours. Going in:

  • No bruises, no cuts, no soft spots.
  • Cured first where applicable: onions and garlic need 2–3 weeks of dry curing before storage; winter squash needs 7–10 days at 25–30 °C to harden the skin.
  • Wash if you want to, but store them dry — Alberta publishes that root crops can be washed provided they are dried before going into storage, and that wet produce should be laid out on newspaper or dried with a fan. Moisture in storage is the problem, not washing.
  • Cull weekly. One rotten potato turns ten others into a slimy mess in a week.

Corrected 19 September 2026: this list used to say "Don't wash before storage — washing introduces moisture and removes the natural protective coating." Alberta Agriculture's Home Vegetable Storage, which this page cites, publishes the opposite permission: root crops can be washed provided they are dried before going into storage, and wet produce should be laid out on newspaper or dried with a fan. They give no instruction not to wash and nowhere describe a protective coating; both were ours. Alberta's requirement is dry storage, not unwashed storage, so produce you brushed and stored dry meets it too. The moisture half of the old wording was right — it was the prohibition that was not.

Every guide in this method

Sources