Fish sauce is made by packing small fish and/or fish blood and innards into large barrels or jars layered with salt and setting the barrels out in the hot sun for around a year. The fish is digested by its own digestive enzymes and a clear salty liquid is eventually drained off and bottled. It is quite essential to several cuisines, particularly those of Southeast Asia today and of the Roman Empire.
Today, fish sauce is an important component of the "Pacific Rim Cuisine" rooted in Southern California, and is slowly entering the North American mainstream, particularly through innovative chefs who have found it a wonderful flavoring ingredient.
More on Seafood Products.
Roman Fish Sauces
Fish sauce was so important to the cuisine of the Roman Empire that almost all known Roman recipes call for it. People attempting to recreate dishes from those times often suggest substituting anchovy paste, an ingredient certain to ruin the dish entirely - then tell you it must be "an acquired taste".
Actually, quite suitable fish sauces made by methods very similar to those of ancient Rome are easily available in any market catering to a Southeast Asian community. Also, a fish sauce called Colatura di Alici is produced in Italy today, though it's more concentrated than the original Roman or Southeast Asian products.
Originally, a fish sauce called "garos" was brought from Greece to Rome. The Romans took to it and established factories to produce it in quantity. This became a major industry, particularly in Spain, just as it is in Thailand and Vietnam today. Some fish sauce was still being made in Spain during Moorish times. Whether there is any connection between the Greek fish sauce and Southeast Asian products can not be known, but the naturalness of its development from salt preserving fish requires no such technology transfer.
The basic difference between the Roman fish sauce and the current Thai product is the Thai practice of using only fresh whole anchovies. The Romans sometimes used other fish and enhanced the mix with extra fish blood and guts, or for higher grades may have used mostly the blood and guts. This would produce a faster fermenting product of higher concentration. Note that in southern Thailand a fish sauce called Tai pla is made entirely from mackerel entrails - and it is definitely stronger than regular Thai fish sauce.
The Romans had different grades of fish sauces and used several names for them. To the best of current knowledge this is how it shakes out:
This fish sauce is made in Italy today, but it's not known if by an ancient process or one just a few hundred years old. It does differ substantially from the original Roman product where the end objective was fish sauce.
The name means "filtration of anchovies" and it's a byproduct of salting anchovies in barrels. Made this way the quantity is small and it is highly concentrated and quite expensive. A price of about $7.50 an ounce makes it quite attractive to chefs at fancy restaurants, but that isn't to say it isn't worth it. Just a couple of drops per serving will do in any case.
Thai fish sauce is of similar strength as drawn from the barrels, but
is diluted to about 20% when bottled. Photos
These sauces are heavily used in Thailand and Vietnam taking the place soy sauce holds in China and Japan. It is both a flavoring element and provides the salt for the dish it is included in. The great majority of Thai and Vietnamese recipes include at least some fish sauce.
This type of fish sauce is also important in the Philippines, but is less used in other countries of Southeast Asia. Fermented shrimp paste, fish paste and other similar condiments are more prevalent in those countries.
Subst: There is no truly satisfactory substitute for fish sauce. A fermented yellow bean sauce is about as close as you can get, and that would be suitable for strict vegetarians, but it is not clear. Lacking that, you would have to use plain salt but an important flavor element will be missing.
Thai fish sauce is now common in Southern California because of the many Asian communities here, but it's also being adopted into the famous "California cuisine" - expect it to spread. Here are the national names for it, as best I could find them, anyway.
Fish sauce is made by layering salt and freshly caught anchovies in large barrels or crocks and setting the barrels out in the hot sun for a year or up to two years. The fish are digested by their own digestive enzymes. The clear fish sauce is then drained through a tap at the bottom of the barrel, filtered and diluted with water to the desired strength, usually about 20%, and bottled. Some bottles carry designations like 30°N, 40°N, 50°N. This is a measure of the nitrogen content, which correlates with the amount of protein in the fish sauce. Lower numbers indicate a lighter sauce.
The "first extraction" provides the top grade sauce. The barrels may then be refilled with salt water for a second extraction but that "cooking grade" product isn't commonly exported to the US. The process of making fish sauce is time consuming and expensive, so some manufacturers add hydrolized wheat protein, acids, MSG and other additives to speed digestion and mask defects. Check the label.
Buying: Look for a perfectly clear light amber color and an ingredient list including only Anchovies, water, salt and sugar. Most shipped to North America has some sugar, which may not be included in the same brand as sold in its home market. Price as a guide is rather unreliable here in Southern California, so it's probably even less reliable elsewhere.
There are probably at least 30 brands sold in Los Angles. Most come from Thailand and the Philippines but Vietnamese is becoming more common. Some Thai sauces are "Vietnamese style" and have Vietnamese lettering along with Thai. This is said to indicate they are slightly lighter and less salty than normal Thai practice.
Philippine fish sauces are considered heavier and undesirable for Thai and Vietnamese cooking. They are generally made from a number of different fish rather than just anchovies, harking back to the Roman practice of using a single fish species for the top grades and just about any fish for the lower grades.
Here are a few notable brands.
I would like to point to a comparison of 13 fish sauces on a Web site named "Our Daily Brine". There were only two tasters, neither with any Asian credentials, nearly all their comparisons were straight from the bottle, and their results are very much at odds with expert Thai and Vietnamese cooks. They placed Red Boat at the top, and brands preferred by highly experienced Asian cooks (Golden Boy, Squid and Three Crabs) at the bottom. I suggest this review be disregarded.Other Fish Sauces
This is a blend of ingredients apparently intended to bring Asian flavors to England in a convenient to sell and use bottled form. It appeared about 1830 but several cute stories of its creation are in conflict with each other and with history. All are probably false.
Since the first real ingredient after vinegar and sweeteners is "anchovies", actually salt digested anchovies, I'm including it here in the fish sauce category. The current Lee & Perrins ingredient list is: vinegar, molasses, sugar, anchovies, water, hydrolyzed soy and corn protein ("concealment names" for MSG), onions, tamarinds, salt, garlic, cloves, chili peppers, natural flavorings, shallots.
Fish sauce, tamarind, chilis and shallots are often used in various
combinations with each other in Southeast Asia, though never put up in a
Laos - Pla Daek &
This sauce is very popular in the Philippines, particularly the northern Iloco region. It is pretty much what's left in the bottom of the barrels after the patis fish sauce is drained off. It might be similar to the Roman allec but we're not sure. It may be ground smooth or it may have whole anchovies in it as the photo specimen does. Monamon Dilis is made from anchovies but Bagoong Terong is made from a fish called "bonnet mouth fish".
This sauce is very strong, extremely salty and the smell is way
stronger and fishier than regular fish sauce. Now we're definitely
getting into that "acquired taste" space.
This very pungent sauce made with anchovies and salt similarly to regular
fish sauce, except it still has ground up anchovies in it. It may be
similar to the Roman allec, we don't know for sure.
It is very common here in Southern California in small but tall 7 ounce
bottles under the name Mam Nem. I haven't seen it under the Thai name
(which may be variously spelled). For recipes be sure to check the
label for sugar - there should be none. The sugared ones are table
condiments. This sauce is most widely used with pineapple and other
ingredients to make the popular
Mam Nem Dipping Sauce (recipe).