Vegetable · stem

Lacto-fermenting fennel: 2.50% salt, 10.0days at 68 °F

The crisp bulb ferments into a softly anise-scented pickle that keeps a satisfying crunch. Fennel's licorice notes mellow as it sours, making it a favorite in Italian giardiniera and as a foil for rich foods. The fronds can be fermented along with the bulb for extra aroma.

Salt calculator

Enter your vegetable weight and a salt percentage. We return the exact salt mass in grams, plus teaspoons for each common grain.

Vegetable weight

grams

Salt percentage

Salt grain

Grain matters: one teaspoon of Diamond Crystal weighs half as much as one teaspoon of fine sea salt. Weigh in grams when you can.

25g salt

4.39 tsp 1.46 tbsp 0.88 oz

Based on Fine sea salt at 5.69 g/tsp.

Safe range for lacto-fermentation. 2% is the most common default for cabbage, kimchi and pepper mash.

All salt grains

Grain	Grams	Teaspoons	Tablespoons
Diamond Crystal kosher	25 g	8.8	2.93
Morton kosher	25 g	5.21	1.74
Fine sea salt	25 g	4.39	1.46
Pickling / canning	25 g	4.55	1.52

Default salt: 2.50 %
Salt range: 2.00% – 3.00%
Time @ 68 °F: 10.0 days
Target pH: 3.60
Water content: ~90%
Preferred styles: giardiniera component, lacto ferment, brine pickle

Technique

Trim the stalks, halve the bulb, and slice 3-5mm or cut into wedges. Cover with a 2.5% salt brine (25g salt per liter); add a few fennel seeds or a strip of lemon peel if desired. Weigh below the brine and ferment 7-14 days at 65-72°F, then refrigerate while still crisp.

Source: NCHFP (UGA) — fermented brine-pickle method. Last verified 2026-06-27.

Frequently asked questions

What percent salt for fermenting fennel?

2.50% by weight is the default for fennel (workable range 2.00%–3.00%). For 1000g fennel, that's 25.0g salt. Use non-iodised salt and weigh in grams — teaspoon equivalences vary by salt grain. Source: NCHFP (UGA) — fermented brine-pickle method.

How long to ferment fennel?

10.0 days at 68°F (20°C). Cooler kitchens (60-65°F) slow fermentation; warmer kitchens (75-80°F) roughly halve the time per 10°F increase. Start tasting from day 5; target pH 3.60 or below indicates complete primary fermentation.

What's the best technique for fermenting fennel?

What category is fennel for fermentation?

Fennel is a stem vegetable. The crisp bulb ferments into a softly anise-scented pickle that keeps a satisfying crunch. Fennel's licorice notes mellow as it sours, making it a favorite in Italian giardiniera and as a foil for ric… Preferred fermentation style: giardiniera-component, lacto-ferment, brine-pickle.

The kit for fermenting Fennel

A short, honest kit for lacto-fermentation. The scale is the one that matters most — everything here is by weight.

Digital kitchen scale (0.1 g)Salt % is by weight, not volume — a 0.1 g scale is what makes the math above accurate.View on Amazon →
Glass fermentation weightsKeep vegetables submerged under the brine line so they ferment safely without mould.View on Amazon →
Airlock fermentation lidsLet CO₂ escape while keeping oxygen out — wide-mouth lids that fit standard jars.View on Amazon →
Wide-mouth mason jarsThe workhorse vessel for kraut, kimchi and brine pickles — 1 qt and ½ gal sizes.View on Amazon →
Pickling / fine sea saltPure salt with no iodine or anti-caking agents, which can cloud brine and inhibit fermentation.View on Amazon →
Stoneware fermentation crockFor scaling past the jar — a water-sealed crock for 5 L+ batches with built-in weights.View on Amazon →

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New to fermenting? See the complete kit, in order →