There’s nothing quite like a good strong-aroma baijiu. I say this not just with a twinge of nostalgia—flashbacks to steamy Chengdu dining halls filled, joyous murmurs and mouthwatering Sichuanese dishes. It’s more than that complex fruity-floral bouquet, or that funky umami finish. It’s something in the drink’s bones, the singular way in which it is made.
Strong-aroma baijiu is ingenious. The Sichuanese distillers who created it found a way to stretch every ounce of starch in the sorghum kernel. They borrow and give back to the local environment, and they develop tastes and scents over months, years, centuries. It’s an elegant, self-perpetuating cycle.
Continuous mud pit fermentation and distillation is a novel process without many analogues in world spirits. For all but the most conceptual of thinkers, the process is a bit confusing. But when you sit down and sketch it out on paper it clicks. You sees that it is a cycle, one in which everything ingredient is utilized to its full potential.
I am no great artist, but thankfully I happen to know an immensely talented one in Christina Chung. So it is with great pleasure that I share her representation of the strong-aroma production process.
- Fermentation. Fermenting sorghum is in sealed mud pits for 2-3 months, during which time much of the alcohol sinks to the bottom and the mud walls and floor absorb ambient microorganisms. This is where the process begins and ends.
- Extraction and distillation of top layer of fermented mash. The top layer of mash—approximately 20% of the pit’s volume–is the driest and least-flavorful. The distillers extract the top layer of fermented mash (a) and distill it (b). The spent mash is fed to pigs (c), from whence it will return to the soil. The distillates are collected and stored (d).
- Extraction of remaining mash and addition of fresh grain. The distillers remove the rest of the mash a layer at a time, and stir in fresh red sorghum grain (a). The amount of fresh grain added is roughly equivalent to the amount discarded in step 2.
- Simultaneous distillation and steaming. The blended grains are distilled in batches. Because baijiu grains are steamed and distilled in the same Chinese pot still, the fermented grain from step 1 is distilled at the same time that the fresh grain from step 3 is steamed. The distillers collect and store the baijiu from each batch separately.
- Removal and cooling of mash. The distillers remove the grain from the still, splash it with water and rake it over the floor to cool it down to a temperature more suitable to sustain yeast.
- Application of qu to start fermentation. Strong-aroma qu is made by combining water (a) and wheat (b) into bricks and letting them naturally absorb microorganisms from the surrounding environment (c). These bricks are dried in the sun (d) and then pulverized into a powder (e). The distillers sprinkle the qu onto the cooled mash, which will simultaneously convert the sorghum’s starches into sugar and sugar into alcohol to initiate fermentation. Then it’s back in the pit with the mash (step 1)!
- Time for a little post-production. The raw distillates collected in steps 2 and 4 rest in terracotta clay or stainless steel vats, usually for at least 2-3 years.
- The various batches of aged baijiu are assessed for taste and blended together with water to reach the desired strength.
- The baijiu blends are pumped into bottles, and ideally served alongside delicious Sichuanese cuisine.
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