Daqu

Updated: 2026-09-15

Overview

Daqu is a traditional Chinese fermentation starter integral to the production of baijiu, a distilled spirit. It is made from a mixture of wheat, barley, and peas, which are ground, shaped into bricks or cakes, and left to ferment naturally. The microbial cultures in Daqu—including yeast, molds, and bacteria—drive the fermentation process, imparting unique flavors and aromas to the final product. Daqu is categorized by its production method and microbial composition, with variations such as high-temperature Daqu (used for strong-aroma baijiu) and medium-temperature Daqu (common in light-aroma baijiu). Its quality directly affects the taste, aroma, and alcohol content of the fermented liquor.

Physical and Chemical Properties

Daqu appears as solid, porous bricks or cakes, often with a rough texture and earthy hue. It is insoluble in water and stable at room temperature but sensitive to humidity and temperature fluctuations. The key chemical components include starches, proteins, and enzymes (e.g., amylase, protease), which break down raw materials during fermentation. Microbial activity is its defining feature, with dominant species like Saccharomyces cerevisiae (yeast), Aspergillus (mold), and lactic acid bacteria. These microorganisms produce ethanol, organic acids, and esters, contributing to the complexity of baijiu. Daqu’s quality is assessed by its microbial load, moisture content (typically 12–15%), and enzymatic activity.

Main Applications

Daqu’s primary use is in baijiu production, where it serves as a starter culture for fermenting grains like sorghum, rice, or corn. It is also employed in making traditional fermented foods such as soy sauce, vinegar, and fermented bean pastes. The choice of Daqu type (e.g., high- vs. medium-temperature) determines the flavor profile of the final product. In industrial settings, Daqu is sometimes supplemented with pure microbial strains to standardize fermentation. Artisanal producers, however, rely on natural inoculation for terroir-driven flavors. Its applications extend to niche culinary uses, such as fermenting pickles or meat products.

Safety and Storage

Daqu is generally safe for use in food production but requires proper handling to avoid contamination. It should be stored in a cool, dry environment (below 25°C) with low humidity to prevent mold overgrowth or loss of microbial viability. Suppliers often vacuum-seal Daqu to extend shelf life (up to 12 months). While non-toxic, individuals with mold allergies should avoid direct contact. Industrial users should monitor Daqu for aflatoxin contamination, though this is rare in reputable sources. Disposal follows standard organic waste protocols.

B2B Procurement Guide

When procuring Daqu, prioritize suppliers with certifications (e.g., China’s GB/T standards) and batch-specific microbial analysis reports. Key metrics include viable cell count (>10^8 CFU/g) and moisture content (12–15%). High-quality Daqu exhibits uniform texture and a balanced microbial profile. Bulk prices range from $5–$20/kg, with artisanal or specialty Daqu commanding premiums. Negotiate contracts with flexible delivery schedules to account for seasonal production cycles. For international buyers, ensure compliance with import regulations for microbial cultures.