Curtido (Salvadoran Fermented Slaw)

The bright Salvadoran slaw served with pupusas: shredded cabbage, carrot, and onion soured with oregano and chile into a crisp, tangy relish. Because it’s shredded, you dry-salt it — the salt draws out enough of the vegetables’ own liquid to form the brine, no added water.

Ingredients

Salt here is 2.0% of the vegetable weight (the dry-salt convention) — there is no added water in the denominator. Shred everything thin so it weeps freely and packs under its own brine.

Ingredient	1 Jar (~1 L)	1 Crock (~2 L)
Green cabbage, shredded	600 g	1,200 g
Carrot, grated	120 g	240 g
White or yellow onion, sliced thin	120 g	240 g
Non-iodized salt (2.0% of veg weight)	17 g	34 g
Dried oregano (Mexican if available)	1 Tbsp	2 Tbsp
Red-pepper flakes or sliced chile	1 tsp	2 tsp
Garlic, grated (optional)	1 clove	2 cloves

Yield

One quart jar of finished curtido (~840 g vegetables once packed). The crock doubles it.

Calculated values

Value	Target
Dry-salt % (of veg weight)	2.0% (band ~1.8–2.5%)
Target finished pH	3.4–4.0
Ferment temp	18–22 °C / 64–72 °F
Day range	3–7 days (shred ferments fast)

Salt is veg_g × 2.0 / 100. For the jar: 840 × 0.02 ≈ 17 g. Confirm and correct for salt purity with the dry-salt calculator.

Readiness window

Shredded vegetables sour quickly: bubbling and tang appear within 2–3 days. Curtido is traditionally eaten on the younger, crisper side — pleasantly sour and still crunchy rather than fully kraut-soured.

Done when: it’s pleasantly sour and bubbling has slowed — usually 3–7 days — and a calibrated meter reads pH 3.4–4.0. Arrest by refrigerating at 2–4 °C.

Method

Weigh and shred

Shred the cabbage, grate the carrot, and slice the onion thin. Put it all in a large bowl on a tared scale and record the vegetable weight — this single number sets the salt.

Calculate and add the salt

Dry-salt is 2.0% of vegetable weight — for ~840 g that’s ~17 g. The dry-salt calculator confirms the grams; the fermentation predictor estimates days at your temperature.

Salt, massage, and add spices

Sprinkle the salt over the shreds and massage 5–10 minutes until the vegetables soften and weep. Rest 15 minutes and massage again until a pool of brine forms when you press. Mix in the oregano, chile, and garlic.

Pack under the released brine

Press the slaw firmly into the jar so its own brine rises above it, leaving ~2–3 cm headspace. Set a weight on top so nothing floats. If the brine doesn’t quite cover after an hour, top with a little 2% brine (20 g salt per 1 L water) — never plain water.

Ferment at 18–22 °C and burp

Cover loosely or fit an airlock, out of direct sun, and burp daily if sealed. Taste from day 2.

Finish by pH, then chill

When pleasantly sour and still crunchy — usually 3–7 days — confirm pH 3.4–4.0 with a calibrated meter, then refrigerate at 2–4 °C to arrest.

Variations / mix-ins

Red cabbage: swap part of the green cabbage for color.
More heat: add fresh sliced jalapeño or a dried chile.
A splash of vinegar at serving: traditional cooks sometimes finish the bowl with a little vinegar for extra brightness — add it at the table, after fermenting, not in the jar.