[BOOK] Flavor Profile #5: Nanru, Red Fermented Tofu

Nanru, red fermented tofu - (南乳)

Introduction

Similar to douchi fermented soy bean, furu fermented tofu is another category of diverse fermented soy products that’s packed with umami.

And similar to douchi fermented soy bean, furu fermented tofu is generally made by letting fungus, mucor, or bacteria grow on smaller tofu cubes for 7-10 days, then mixed with seasoning like salt, chili, spices, and liquor before moving onto a longer fermentation process.

But not to confused furu with the popular street snack stinky tofu, "choudoufu" (臭豆腐). While traditionally some stinky tofu is made with a similar method as furu fermented tofu, the stinky tofu that’s most well-known nowadays is usually made by soaking tofu cubes in a shortly fermented brine.

Such as the deep-fried black ones from Changsha, Hunan (which contains the classic stinky tofu brining ingredient iron(II) sulfate):

And there's the soft greyish green one from Shaoxing (where Shaoxing wine is from) that's soaked in a brine made from amaranth stems:

While furu is called fermented tofu, you should not consume it directly as tofu but rather use it as a condiment. I remember some people complained about how they ate a whole cube of furu as tofu and it was incredibly salty. Just a small reminder in case you’re trying it for the first time.

Just as douchi fermented soy beans, furu also comes in many varieties. It usually comes in three big categories as white, red, and green.

For this flavor profile, we're talking about "Nanru (南乳)", a.k.a. red fermented bean curd that belongs to the red family. The character "南/nan" means "south", meaning that it's a product of south China. Red yeast rice is the ingredient that defines nanru, giving it the characteristic red color and a deep rice wine aroma.

(A Cantonese brand of nanru)

In Cantonese cooking, nanru is a distinct flavor profile with some pretty intriguing applications such as in sweet baked goods, like chicken cookies. But of course, the most classic usage of nanru lies in savory dishes. It’s basically a must-have for a Cantonese lamb stew, and you may also recognize that almost rice-wine liked fragrance from some roasted crunchy nanru peanuts.

Nanru flavor goes really well with garlic and five spices, which are the two go-to add-ins when using this ingredient.

Recipe #1 Deep-fried crispy pork belly with nanru 南乳炸肉

This crispy pork belly has a crunchy coating with rice flour + tapioca starch and a vibrant red color from nanru. It’s believed to be a Hakka dish but it’s seen throughout Guangdong either at street food stalls or restaurants. It’s a great snack or a side dish, even fits perfectly in the context of Vietnamese vermicelli platter (check out the note on how we make the meal).

Ingredients:

• Pork belly (五花肉), skinned, about 300-350g

For the marinate:

• Nanru, red fermented tofu, (南乳), 1 tbsp plus some liquid
• Oyster sauce (蚝油), 1 tbsp
• Light soy sauce (生抽), 1/2 tbsp
• Liaojiu, a.k.a. Shaoxingwine, 1/2 tbsp
• Garlic, 1 big clove.
• Sugar, 1/2 tbsp
• Salt, 1/2 tsp
• Five spice powder, 1/2 tsp

For the coating:

• Rice flour, 3 tbsp
• Tapioca starch, 3 tbsp

Process:

Pound the garlic with salt and sugar in a mortar till it’s pasty. Add in the remaining marinate and pound everything into a sauce.

Cut the pork horizontally into three half-inch-ish slabs.

Gently massage the pork with the nanru sauce for a minute or so, marinate for at least 30 minutes or up to 48 hours in the fridge.

Mix the rice flour and tapioca starch together, pour it onto a rectangle or wide plate that a slab of pork belly can lay flat, spread it out and create an even layer of flour. Place the slab of pork onto the coating flour, gently press down, flip, then grab some dry flour and lightly press it into any cracks that didn’t get the coating.

Repeat till the both sides are coated with coating flour, lay it on a flat surface. Work through the slabs, and we can fry.

Heat up 2-3 cups of oil in a wok till it reaches 140C, grab a slab and carefully lay it in. You can fry two to three slabs at one go, but don’t be too greedy as we want to keep them as “pork fillets”.

Fry it at 140C for 3 minutes, take it out. Now heat the oil to 190C, quickly dip the belly in for a double fry for 45 seconds then immediately scoop it out with a strainer.

Let it cool down a bit on the strainer, then chop it into half-inch wide slices and serve right away.

Note:

When making this, we like to have it in the context similar to a Vietnamese Banh Hoi. Here’s what we do:

Cook thin rice noodles according to package, or the way you’re used to. I just boil them directly. Some people swear by soaking it for a couple hours then do a quick blanch. Up to you. After it’s done, strain and leave it in the strainer to cool down and set. You can cut out small chunks of rice noodles for serving using scissors, it’ll look prettier (see picture below), but it’s not mandatory of course.

Wash a head of Romain lettuce and spin dry the leaves. Optionally prep some shiso/perilla leaves or some other Southeast Asian herbs that you like, maybe Thai basil or mint.

Make a Vietnamese dipping sauce Nuoc Cham, see ratios below.

To eat, grab a piece of lettuce, place a shiso leave or herb of choice onto the leave, lay some rice noodle on it, then a piece of the crispy pork belly. Wrap it up like an little envelop, dip in the sauce, and devour.

Nuoc Cham ratios:

a. 1 part sugar, 2 parts fish sauce, 1 part lime juice, 2 parts water (1:2:1:2)

b. 1 part sugar, 2 parts fish sauce, 2 parts lime juice, 3 parts water (1:2:2:3)

c. 1 part sugar, 1 part fish sauce, 2 parts lime juice, 2 parts water (1:1:2:2)

On top of the liquid base, add half part minced garlic, a lot (like… a lot) of ground black pepper, plus a couple Thai bird’s eye for heat and a small pinch of MSG to taste.

Recipe #2 Stir fried lotus root with nanru sauce 南乳炒藕片

In addition to the classic “garlic + five spice” add-in, the nanru flavor profile works great with together with other sauces like hoisin, peanut butter, sesame paste, Hokkien Shacha sauce, etc. Many restaurants would make their own nanru sauce for their red fermented tofu flavor dishes and in this recipe we want to introduce a classic combo of nanru + nut sauce.

Ingredients:

• Lotus root (莲藕), peeled and thinly sliced, about 400-450g. Use jicama or other crunchy vegetables if you can’t find lotus root.

For the sauce:

• Nanru, red fermented tofu (南乳), 25 gram, plus a tsp or two liquid from the jar
• Peanut butter (花生酱), 5g or 1 tsp
• Sesame paste (芝麻酱), 5g or 1 tsp
• Liaojiu, a.k.a. Shaoxing Wine (料酒), 1 tsp
• Light soy sauce (生抽), 1 tsp
• Garlic, 1 big clove.
• Sugar, 1 tsp
• Salt, 1/4 tsp
• MSG (味精), 1/8 tsp

Process:

Pound the garlic with salt, sugar, and MSG in a mortar till it’s pasty. Add in the remaining condiment and pound everything into a thick sauce.

Before frying, to a pot of boiling water, blanch the lotus root slices for 1 minute, strain, quick rinse to get rid of excesses starch.

Long yau, get your wok pipping hot, shut off the heat, add in the oil, here about 1 1/2 tbsp, give it a swirl to get a nice non-stick surface.

Heat on low, add in the nanru sauce, fry it till fragrant and no longer clumpy.

Turn the heat on high, add in the lotus root, quick fry for about 1 minutes, heat off and finish off with a touch of toasted sesame oil.

Note:

If you don’t have sesame paste, you can straight up use 10g of peanut butter instead. Vice versa.

If you want the dish to look pinker and have a bit more sauce, add in a slurry of 2 tbsp water, an additional 1 tsp red juice from nanru jar, and 1 tsp cornstarch before you shut off the heat, let it quickly coats the lotus root and then heat off.

This sauce is very thick, if you want it to look shinnier, up the frying oil quantity to 2 tbsp or even 2.5 tbsp.

Stir frying jicama is the same deal, quick blanch, rinse, and fry. The natural sweetness creates a nice balance with the savory sauce.

The amount of sauce shown in the recipe can be used in one or two portions of stir fry depend on how heavy of a taste you prefer. It can be a touch on the salty side in one stir fry if you like things to have a lighter taste.