What is Qu Exactly? On Rituals Behind Fermentation Cakes, Before We Knew Microbes Existed.
A thatched hut, young boys, and the right moon dates to start your ferment.
Hello friends,
To start the New Year I thought I’d finally start talking about what Qu is. While qu ferments are much harder to find information about, it is very much a topic dear to my heart. Gastronomes and chefs today are often familiar with the culinary power of Japanese koji, innoculated grains used to make sake, miso, mirin, and soy sauce. Much less is known about traditional yeast cake starter known as Qu (pronouncd “chu”).
Hailing from China, qu (also known as jiuqu 酒曲) is a wild rice wine starter cake made from ground grains such as wheat, sorghum, and rice flour. Crushed grains are mixed with water until they can form a dry dough, and the mixture is then either packed into large molds or hand-formed into small cakes or balls. The cakes are then left to dry, traditionally in a thatched straw hut and often dried on top of plants belonging to the Artemisia family. After a few days, mold, yeasts, and other bacteria in the environment eventually find their way inside the entire cake. The cakes will dry out from the outside in, and microbes, chasing moisture, will migrate into the center of each cake, all the while producing a whole host of saccharifying enzymes to help them break down carbohydrates into digestible sugar.
Like koji, qu also contains Aspergillus oryzae. Where it differs is that it also contains a whole host of other mold species and bacteria, and it is the microbial diversity of qu that leads to such interesting flavors and aromas in traditionally fermented rice wine. In Korea, you will find a similar starter called nuruk, which is used to make makgeolli and other rice wines; in Vietnam you find a similar rice wine starter cake called men. All over Southeast Asia you will find that each country (indeed region) will have their own version of this microbial cake. In China, you can find modern jiuqu used to make jiuniang (sweet rice porridge) or rice wine on platforms like Taobao or in local medicinal stores, but what fascinates me the most about qu are the ancient historical rituals that surround its production:
One of the most important preserved texts that we have as historical record of ancient Chinese agricultural practices today, the Qimin Yaoshu (Essential Techniques for the Welfare of Common People), describes the practices of making one kind of qu from wheat:
“Before sunrise on the first day of the seventh moon (usually August), a boy in dark clothing is sent to draw twenty hu of water while facing west. No one else is allowed to touch this water. If there is too much water, the unused portion may be discarded, but it must not be used by anyone. For the caking of the ferment, only young boys are employed and they too must work facing west. No dirty person is to be employed, and the work is done away from living quarters.”
Looking back at these descriptions and armed with today’s basic knowledge of sanitation, we can reason why these practices might have worked: water drawn by a single person and not contaminated by other hands, clean working environments, and clean workers. One can only speculate why or if there was a purpose for facing west—perhaps the wind provided good air circulation that aided in keeping the working environment sanitary in the warmer month of August.
As for the choice of using a young boy to draw water, I am neither a historian nor an expert on ancient Chinese agricultural practices, but in other parts of the Qimin Yaoshu, there are some mentions of women not being allowed to make certain products like vinegar, especially if they are menstruating for fear of spoiling the product. In all the accounts I’ve read about traditional qu production, boys are always the ones carrying out the process. Now that I have your eyebrows raised, we can acknowledge that some practices are perhaps best left to the past, as this female qu maker will be happy to do so.
The Qimin Yaoshu continues:
“The raw ferment cakes are fabricated in a hut roofed with thatch (straw), not with tiles. The earth must be clean (firmly packed) and free from loose dirt. There must be no damp spots. The floor is divided into squares with footpaths so that four alleys are formed. Figures are sculpted from the raw ferment mix. Some of them are set up as ‘ferment kings’ and there are five kings. Then a person from the owner’s family is chosen as the master of ceremonies. Neither a servant nor a guest may serve as the master. Offerings of wine and dried meat are made to the ‘ferment kings’ in this way: The king’s hands are moistened and used as bowls to receive gifts of wine, dried meat and boiled pastry.
The master of ceremonies reads the sacrificial incantation three times. Everyone kneels twice to the deities. The wooden door to the hut is then close and sealed with mud to prevent the ingress of wind. After seven days, the door is opened, the ferment cakes turned over, and the door again closed and sealed with mud.”
Again, from the modern perspective, we might see why some of this translates into successful fermentation. Thatching the roof with straw, which harbors Aspergillus oryzae, Aspergillus sojae, and bacillus subtilis necessary for certain kinds of ferments common to East Asia, including miso, huangjiang, doubanjiang, gochujang, and doenjang. Keeping a dry, clean room by which the door was repeatedly sealed with mud and left alone for several days before opening again ensured protection against rats, insects, and wandering passerby. And while building deities out of crushed grain and water to watch over fermenting yeast cakes turned out to be a practice that diminished into extinction, contemporary artisanal producers of nuruk and qu still use straw-filled rooms to dry out their starter cakes.
February Stage & Popup at Hana Makgeolli
Now that I’ve whet your appetite for the intriguing world of wild Asian yeast cake starters, I’m happy to announce some exciting plans. In February I’ll be taking a break from classes and fermenting in Berlin. I’ll be going back to my home city of New York, where I’ll be staging at Hana Makgeolli, an artisanal rice wine brewery working with traditional brewing practices and the wild fermented cake nuruk. I’ll also be hosting a popup in their tasting room at the end of my stay there. Think lots of fried snacks and fermented small plates, anju-style, to accompany their lovely range of sools and botanical makgeollis. I’m really looking forward to learning from their founder and master brewer, Alice Jun. More updates on that soon.
Till then, stay warm & thanks for reading.
Polly
This is very fascinating. I thoroughly enjoyed your article. Best of luck when you return to New York.
How beautiful!