Reference point
A little shrimp paste on the tip of a chopstick, held two hand-spans from your nose.
Do this before you read on. An entry only works when you have just smelled the thing.
Strongly fishy, salty, with a clear ammonia note and a deep layer of umami underneath. It takes over the air at once.
Compared with fish sauce, shrimp paste is cloudier, heavier, and has a much stronger ammonia note. The reason is the different raw material and degree of breakdown: shrimp paste is fermented from whole tiny shrimp, so it includes the shells and protein broken down further.
Squeezing in lime and whisking it until frothy changes the smell noticeably. The acid neutralises part of the volatile amines, which is why this step is essential rather than decorative.
How to smell it
Put a little shrimp paste in a small bowl and smell from two hand-spans away. Then squeeze in lime, whisk until frothy, wait a minute and smell again. The gap between the two is the effect of acid on the amines.
Why this one is hard
Because the urge to avoid it is very strong. The technique is to keep your distance and smell briefly, rather than trying to endure it up close.
Don’t confuse with
This entry
Fermented shrimp paste
Fermented family
Shrimp paste is cloudier and heavier, with a much stronger ammonia note, because it is fermented from whole shrimp.
Scientific note
Shrimp paste contains trimethylamine together with short-chain fatty acids and sulphur compounds. Trimethylamine forms when bacteria reduce the trimethylamine oxide naturally present in marine animal tissue. It boils at three degrees, so it exists as a gas under normal conditions — which is why the smell spreads further and faster than almost anything else in this dictionary.
In Vietnamese life
Shrimp paste is one of the most divisive foods in Vietnamese cuisine, and that division lies almost entirely in smell rather than taste. Very few foods have their acceptance decided so completely by smell.