Thai Crab Paste - [Gach Cua Xao Dau
This is a typical Thai crab paste by a leading Thai brand,
Pantai. According to the label, the crabs were caught in the Pacific
ocean. The bits of crab in the paste were surprisingly firm.
Ingr: Crab meat (60%), soya bean oil (28%), garlic, salt, pepper,
flavor enhancers (monosodium glutamate E621, disodium 5'inosinate E631,
disodium 5'guanylate E627) color (paprika oleoresin E160c)
Paddy Crab Pastes / Sauces
In Laos and the Issan region of Thailand, the rice paddies are
infested with tiny freshwater crabs. They are disliked by farmers,
because they eat young rice shoots. They are hard to get rid of because,
when the paddies are dry, they just tunnel into the mud and hibernate
until the water returns. On the other hand, they do provide a significant
supplementary income for the rice farmers. The crabs are captured, salted
and ground up into a seasoning paste that is well liked in Laos,
Northeastern Thailand, and southern Vietnam. This paste is usually
locally made and isn't much available in North America. These crabs are
also sold fresh and unsalted for use in Vietnam's famous Bun Rieu Cua
Rice Crab Sauce for Bun Reiu Soup -
[Gia Vi Cua Nau Bun Rieu (Viet)]
So important is the Bun Rieu Soup, mentioned above, that pre-made sauces
are exported for use by Vietnamese in other countries where the raw
ingredients are hard to find. This sauce was made in Thailand, rather
than Vietnam, but this is reasonable. Thailand is a major manufacturer
of canned and bottled sauces and similar products for export, while
Vietnam is more known for exporting whole natural products. Ingred:
Water, onion, crab meat (18%), garlic, soybean oil, peanut, lemon
grass, chili, sugar, modified cornstarch E1422, monosodium glutamate
E621, salt, paprika natural color E160c.
Rice Crab Sauce - [Nuoc Cot Cua Dong
This is a commercial product that recently showed up in the same freezer
case with the whole crabs and chopped crabs with sauce that were used
in the development described below. The white plastic tub held 1-1/2 cups.
Of that, 1-1/4 cup was water (83% water), and 1/4 cup was sediment, about
half very fine and half somewhat gritty. Made in Vietnam, Ing: Crab,
pure water. In my opinion, my homemade sauce is superior.
Making Rice Crab Pastes / Sauces
I've found incomplete information on making these pastes. I suppose
the writers expect an English speaker would not want to do this and/or
be unable to get the ingredients. Having studied everything I've found,
I believe my procedures are adequately accurate, and I have made these
pastes and sauces.
So, you ask, what does it taste like? In my opinion it tastes pretty
good - fairly inoffensive, and definitely more crab flavored than similar
murky fish sauces. My office assistant noticed a sort of "fishy" smell
when I was concentrating the Laotian paste, but didn't find it
Rice Paddy Crab -
[Boo Kem, Bpoo Kem (Thai, salted); Ba Khía Nguyén Con
This is a salted rice paddy crab. I bought a tray with 14 ounces of
them from the freezer cases of a large Asian market in Los Angeles
(San Gabriel), 2017 US $3.56 / pound. They are up to 1-3/4 inches
across the shell. For use in Green Papaya Salad and the like, the
top shell is pried off and discarded along with the gills under it.
The rest of the crab is broken up and added to the salad. For pastes
and sauces, the whole crab is ground up. For details see our
Rice Paddy Crabs page.
Frozen Minced Crab - [Ba Khia]
Some weeks after I bought the whole frozen salted crabs, the market
added 14 ounce tubs of "Frozen Minced Crab" to the same freezer case,
2017 US $3.41 / pound. "Minced" is hardly the word, they were just
very coarsely hacked apart as they would be for salads. These were
from Vietnam, and had quite a bit of sauce (or salad dressing)
included. Ing: Crab, water, salt, sugar, chili, garlic, vinegar.
- The tub of chopped crab didn't look to be enough for paste, and
there was too much sauce - so I decided to grind together the 14
ounce tub and the 14 ounces of whole crabs.
- Suggestion: Use heavy wire cutters or similar to cut off the
white teeth from inside the claws. They are extremely hard and
difficult to grind.
- You need a powerful high speed blender for the grinding. A
food processor just doesn't have what it takes. An Indian
wet grinder (used to grind rice for idli cakes) would probably
be ideal, but those are scarce and expensive in North America.
- In Laos the Crabs are pounded with Lemon Grass and Guava
Leaves (Mak Sida - from real guavas, not pineapple
guavas). Lacking Guava Leaves, I decided to just use the liquid
sauce from the tub of chopped crabs for flavoring, though there
wasn't enough to make much difference. I certainly could have
added Lemon Grass, but decided to leave that to be added to
In Laos, the crabs would be pounded in a mortar, a project taking a
lot of time and energy, so I used mechanical means. The specimen to the
left in this paragraph was ground in a powerful food processor, but
was just too gritty, so it had to be reground in a blender. As the
blender grinds, you will need to add more and more water so it doesn't
bog down and get overloaded. Smoke coming from the blender base is
not a good sign. The resulting paste will always be a little gritty,
but the grit should be very fine. Commercial products are a bit finer,
but still gritty.
In Vietnam and parts of Thailand, this is as far as the process might
go. The loose paste is strained to produce a liquid sauce (left photo),
and the finely ground debris (right photo) is often used to make crab
cakes. I wrung out the photo example in a strong muslin bag, making a
very fine liquid with no grittiness, but strainers not quite so fine
may also be used. The difference from making the broth for Bun Rieu
soup in Vietnam is that fresh crabs are used rather than salted and
frozen. Salted and frozen are the only ones we can get in North
America (California rice growers are very adverse to having
these crabs in their paddies). You could desalt the crabs by soaking,
but Unsalted crab juice needs to be used right away as it will spoil
In Laos and Issan Thailand -
In the countryside it is desired to have a crab paste that will last
a long time without refrigeration, as the crabs are not readily
available much of the year. For this reason, the ground crab paste
is allowed to ferment overnight, then cooked very slowly in
kitchen embers for about 24 hours, or until most of the water has
evaporated and the paste is dark and very stiff.
Not having kitchen embers available, I put the paste in an
open sauté pan and cooked over very low heat, stirring often
and carefully regulating the temperature. It should be kept above
165°F/75°C, but below 205°F/95°C. If it goes
much above 205°F in the early going it will bubble and splatter
without mercy, and in the later going it might burn. The object here
is not to fry the paste, but to dehydrate it. It should be a dark,
rather stiff paste, but should be taken off the heat and packed
before it becomes so dry it breaks up into crumbs. With precise
temperature control and frequent stirring it should take less than
6 hours. Kept in a sealed container, the paste needs no refrigeration.
My paste didn't come out nearly as dark as it often does in Laotian
homes, probably because of very precise temperature control.