FRES

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 2% salt brine. The salt suppresses spoilage organisms while letting Lactobacillus species thrive. 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, squash, cabbage) keep for 3–6 months at 0–5 °C and 85–95% relative humidity.

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. Master the 2% rule here.
  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: the 2% brine rule

For most vegetables (cabbage, cucumber, carrot, beet, radish), the salt-to-vegetable ratio is around 2% by weight. That means:

  • 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.

2% is a starting point. Kraut traditionally uses 2–2.5%; sour pickles 3–5%; very salty fermented sauces 5–10%. Stick to 2% if you're starting out.

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 — the 2% rule 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.

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 drinks with 0.5–2% alcohol from fermentation — comparable to a very ripe banana. Healthy adults and most older kids can drink freely; pregnant individuals and those avoiding all alcohol should shorten fermentation and refrigerate immediately.

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

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

  • Potatoes — 3–6 months at 4–7 °C, 90% humidity, in the dark. Sprouting happens warmer; cold injury below 2 °C.
  • Carrots, beets, parsnips, turnips, rutabaga — 4–6 months at 0–2 °C in damp sand or peat. Stored loose in a fridge, 2–3 months.
  • Cabbage, kohlrabi — 3–4 months at 0–2 °C, hung by the stem or wrapped in newspaper.
  • Onions and garlic — 4–6 months at 0–4 °C in a dry spot (60–70% humidity). Different from root vegetables; too humid and they rot.
  • Winter squash, pumpkin — 2–4 months at 10–15 °C (warmer than root crops) and dry (50–70% humidity). A spare bedroom works.
  • Apples — 3–6 months at 0–4 °C, 90% humidity. Store away from other vegetables — apples release ethylene, which accelerates ripening on everything nearby.

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.
  • Don't wash before storage — washing introduces moisture and removes the natural protective coating. Brush off dirt; wash before cooking.
  • Cull weekly. One rotten potato turns ten others into a slimy mess in a week.

Every guide in this method

Sources