Douzhi (fermented mung bean milk)

AI Gourmet Analysis

Overview

Douzhi (pronounced "Douzhu", 豆汁, Douzhi) is a traditional fermented beverage that has been popularized mainly in Beijing, China, and is frequently found especially in areas retaining Islamic culinary culture, such as Niujie. Its main ingredient is mung beans (绿豆, mung bean), and it originally has a history as a by-product created during the production process of Beijing traditional dishes such as spring pancakes and zhajiangmian (noodles with soybean paste). Due to its low cost and high nutritional value, it has long served as a preserved food and health drink for ordinary people.

Production and Characteristics

Douzhi is obtained by adding water to the bean dregs (the residue after starch extraction) produced during the process of making glass noodles (fěntiáo) from mung beans and allowing it to ferment. In traditional methods, it is naturally fermented at room temperature for several days, which gives rise to its characteristic sourness and fermented aroma. The final liquid is cloudy white with a viscous texture. It is rich in organic acids, lactic acid bacteria, and B vitamins generated during fermentation.

Taste and Aroma

Douzhi is also known for its highly distinctive taste. Its sharp sourness from fermentation, the green beany smell unique to mung beans, and the complex aroma of fermentation together create a uniquely intense flavor, which can be quite impactful for first-time drinkers. It is recommended to shake well before drinking to prevent uneven flavor and separation of its components. In Beijing, it is strongly favored by health-conscious elderly people and long-time residents, but it is often considered less palatable by people from outside the city and overseas.

History and Cultural Background

Douzhi culture in Beijing dates back to after the Qing Dynasty. Before the advent of advanced fermentation techniques in China, when rice or wheat was scarce, processed foods made with mung beans were often used. As part of the common people's breakfast culture, douzhi has traditionally been served alongside fried dough sticks (youtiao), salted vegetables (xiancai), and baked flatbreads (shaobing). Closely intertwined with Beijing's hutong (alleyway) culture, it has recently been rediscovered as a nostalgic local delicacy and is attracting attention from young people and tourists.

"The Vomit Trinity" and Douzhi

Douzhi is sometimes known for its pungent flavor to the extent that it is jokingly referred to as "the vomit trinity" (嘔吐三件套). This term arose from the strong shock people from outside Beijing or foreign tourists experienced when tasting traditional Beijing dishes such as douzhi, chaogan (stewed intestines), and baodu (tripe). It is said that these are local delicacies yet extremely challenging for outsiders. However, it is precisely this intensity that embodies douzhi's uniqueness and the diversity of Beijing's culture.

Nutritional Value and Health Benefits

As a fermented food, douzhi is rich in lactic acid bacteria, which are expected to have probiotic and immune-boosting effects. Mung beans themselves are rich in protein, dietary fiber, B vitamins, and minerals, and in Chinese traditional medicine they have long been valued for "clearing heat" and "aiding digestion". It is commonly consumed as a nourishing food especially in summer or during periods of poor health.

Modern Douzhi Culture

In recent years, canned and bottled versions have become popular, and douzhi can now be found not only at longstanding shops in places like Niujie, but also in supermarkets and convenience stores. Alongside the rise in veganism and health-consciousness, douzhi is attracting interest from new consumer demographics, and new, easier-to-drink adaptations are being explored while retaining its traditional flavor. When visiting Beijing, it is a dish worth trying, notable for its uniqueness and historic background.