Garum & Fermented Condiment Salt Percentage

base substrate

Whole small fish or fish scraps (garum / fish sauce) — Anchovies, sardines, or mackerel are classic; higher oil content accelerates autolysis.

20–25% of fish weight

Salt — garum / fish sauce — Traditional Southeast Asian fish sauce (nước mắm, nam pla) typically uses 3:1 fish-to-salt by weight, equating to ~25% salt.

15–18% of krill weight

Salt — belacan / shrimp paste — Malaysian and Indonesian shrimp pastes use somewhat lower salt because the product is dried and further cooked before use.

13–15% of final paste weight

Salt — doenjang / Korean soybean paste — Doenjang ferments at lower salt than fish sauce because the soy protein matrix and post-meju mold activity provide additional antimicrobial protection.

6–12% of total weight

Salt — miso (reference) — Lower range than traditional garums; miso is refrigerated and fermented at controlled cool temperatures with inoculated koji rather than wild flora.

5–10% of fish weight

Optional: roasted barley or rice (garum) — Present in some historical Roman garum recipes and some craft modern garums to accelerate fermentation via koji enzymes.

For fish sauce / garum: layer fish and salt in a sealed vessel at a 3:1 (fish:salt) ratio by weight. Allow to ferment in a warm environment (25–35°C) for 12–24 months (traditional), or at 60°C with koji inoculation for 3–4 weeks (accelerated modern garum). Press and filter the liquor; bottle. For shrimp paste (belacan): mix krill with 15–18% salt, sun-dry for 1–2 days, pound, and repeat over 2–8 weeks, developing a deepening purple-brown paste. For doenjang: cook and mash soybeans, form into meju blocks, ferment with wild mold (Aspergillus oryzae) for 2 months, then salt and age the paste for 6–12 months in earthenware onggi.

• Salt percentage should always be calculated against the wet weight of the substrate at the start of fermentation — not the final dried weight, which gives a misleadingly high apparent percentage.
• Minimum safe salt for an unrefrigerated, long-fermented protein product is approximately 15% — below this, botulinum and putrefactive bacteria can dominate even in acidic environments.
• Warm fermentation (28–35°C) dramatically accelerates enzyme activity; traditional Thai and Vietnamese fish sauce producers ferment in direct sun for this reason.
• Colour darkening (Maillard and non-enzymatic browning between free amino acids and reducing sugars) is a desirable quality indicator — a deep amber or chocolate-brown colour signals high free glutamate content.
• Taste for seasoning only after dilution — a teaspoon of fish sauce directly tastes overwhelmingly saline; assess aroma, depth, and umami complexity instead.

• Roman garum / liquamen

  Historical accounts indicate 8:1 fish-to-salt ratios (approximately 11% salt), likely referring to very oily fish (sprat, mackerel) with high endogenous enzyme activity; modern recreations typically increase salt to 20–25% for safety.

• Modern koji-accelerated garum (Noma style)

  Uses 2% salt with koji at 60°C; the low salt is safe only because controlled high temperature (pasteurising for pathogens) and short duration substitute for osmotic protection. Not shelf-stable without refrigeration.

• Trassi / terasi (Indonesian shrimp paste)

  Typically 20–22% salt; darker, more pungent than Malaysian belacan; dried into harder blocks.

• Prahok (Cambodian fermented fish paste)

  25–30% salt; very long fermentation (6–12 months); used as both condiment and cooking paste. Among the saltiest traditional garums.

• Charcuterie Cure Penetration Rate

  Also salt-driven preservation, but in solid muscle tissue; uses 2–3% equilibrium salt versus the 15–25% here.

• Sichuan Brine Pickle (Salt to Water to Sugar to Spirits)

  LAB vegetable fermentation uses 3–5% salt — an order of magnitude below garums — because LAB acidity provides additional protection.

• Lacto-Fermentation Brine (Salt to Water)

  Vegetable brine at 2–3% salt illustrates how protein substrate, unlike cellulose-rich vegetables, requires far higher salt to safely suppress putrefaction.

1. 1.The Noma Guide to Fermentation — René Redzepi & David Zilber
2. 2.On Food and Cooking — Harold McGee
3. 3.Modernist Cuisine: The Art and Science of Cooking — Myhrvold et al.
4. 4.Fermented Foods of the World — W.H. Holzapfel & B.J.B. Wood (eds.)
5. 5.Fish Sauce: Production, Properties, and Food Safety — D.H. Nguyen (Journal of Food Microbiology)

Confidence: high