The Core Ingredients: Fish and Salt
At its heart, traditional fish sauce is made with just two main ingredients: fish and salt. The type of fish used can vary, but small, oily fish are common choices. Anchovies are among the most frequently used fish, valued for their flavor and oil content. Other species like mackerel, sardines, and krill can also be used, depending on the region and desired flavor profile. Sea salt is combined with the fish to start the natural fermentation process, which is critical for both preservation and flavor development. The salt concentration is typically high, between 10% and 30%, which is high enough to inhibit spoilage-causing bacteria while allowing the enzymatic breakdown to occur.
The Fermentation Process
The magic of fish sauce happens during a long, slow fermentation period. The fish and salt are packed into large barrels or vats and left to age. The naturally occurring enzymes in the fish, particularly in the guts, break down the fish protein over time. This process releases free amino acids, including glutamate, which is responsible for the rich, savory umami taste. Traditional fermentation can take anywhere from six months to two years, resulting in a complex, nutty flavor. The resulting liquid, often a clear amber or reddish-brown color, is then drained and filtered to create the final product. Cheaper, mass-produced versions may speed up this process or use additives to achieve a similar flavor profile.
What Else Can Fish Sauce Contain?
While high-quality, traditional fish sauces stick to just fish and salt, many commercial brands include additional ingredients to manage cost, color, and flavor consistency. It is essential to read the label to know exactly what you are consuming.
Common Additives in Commercial Brands
- Water: Often added to second or third pressings to increase yield. This dilutes the flavor and reduces the overall quality, requiring other additives to compensate.
- Sugar: Ingredients like refined sugar, caramel, or molasses are sometimes added to balance the intense saltiness or to mask the flavor of lower-quality ingredients.
- MSG: Monosodium Glutamate is a common flavor enhancer used in some brands to replicate the umami that comes naturally from long fermentation.
- Hydrolyzed Wheat Protein: Used as a flavor enhancer in some brands. This is a crucial point for anyone following a gluten-free diet, as it introduces gluten into the product.
- Preservatives: Chemical preservatives, such as sodium benzoate or potassium sorbate, may be used to extend shelf life.
- Coloring: Caramel color or other dyes may be added to achieve the desired amber hue, particularly in diluted or quickly produced sauces.
Regional Variations
The basic recipe of fish and salt has countless regional iterations across Southeast and East Asia, each with a slightly different flavor profile. Some examples include:
- Nuoc Mam (Vietnam): Often made with anchovies, it is known for being lighter in color and slightly sweeter than its Thai counterpart.
- Nam Pla (Thailand): Typically saltier and with a stronger, more potent flavor. A popular brand, Squid Brand, is a good example of this style.
- Patis (Philippines): A heavier, more assertive fish sauce often used as a table condiment. It's a byproduct of the fermented fish paste, bagoong.
- Colatura di Alici (Italy): A modern Italian version that traces its roots to the ancient Roman garum.
Fish Sauce vs. Soy Sauce: A Comparison
Despite both being fermented condiments that deliver an umami punch, fish sauce and soy sauce have key differences in ingredients, taste, and use.
| Feature | Fish Sauce | Soy Sauce |
|---|---|---|
| Core Ingredients | Fish (typically anchovies) and salt | Soybeans and wheat (for most varieties), salt |
| Flavor Profile | Distinctly salty, briny, and savory, with a funky, intense umami | Salty, savory, with a fermented, malty umami flavor |
| Scent | Intensely fishy in the bottle, but mellows and deepens when cooked | Deep, fermented, and savory, but less pungent |
| Gluten Content | Naturally gluten-free, but some commercial varieties contain hydrolyzed wheat protein | Most common varieties contain wheat and are not gluten-free; Tamari is a gluten-free alternative |
| Best For | Southeast Asian cuisine, marinades, curries, and dipping sauces | East Asian cuisine, marinades, dips, and stir-fries |
Choosing and Storing Quality Fish Sauce
To ensure you are getting the best quality, look for products with a simple, transparent ingredient list. Higher-end brands like Red Boat or those with a higher '°N' rating (indicating protein content) typically offer a purer flavor. Good fish sauce should have a clear, reddish-brown color, similar to whiskey or sherry, with no cloudy sediment.
Fish sauce has a very long shelf life due to its high salt content and fermentation process. It does not need to be refrigerated, as bacteria cannot thrive in it. However, storing it in a cool, dark pantry will help preserve its color and flavor for longer. While it won't truly spoil, older bottles may become darker and more pungent. For the highest quality, you can refrigerate it after opening.
Health Considerations
While fish sauce offers certain health benefits, such as amino acids, protein, and some vitamins and minerals, its very high sodium content is the most important health consideration. One tablespoon can contain over half of the recommended daily sodium intake, so moderation is key, especially for those with hypertension or other health conditions. For pregnant individuals, fish sauce is generally considered safe when consumed in moderation and sourced from a reputable brand, as small fish like anchovies have low mercury levels.
Conclusion
In essence, what does fish sauce contain? At its most authentic, the answer is simple: fish and salt, skillfully fermented over time to produce a complex, umami-rich liquid. While the rise of commercial production has introduced a range of additives and shortcuts, quality versions still stand out for their purity and depth of flavor. By knowing what to look for and reading ingredient lists, you can choose a premium fish sauce that elevates your cooking. For an in-depth guide on selecting quality fish sauce, check out the Michelin Guide's tips on how to choose fish sauce.
