how to make soy sauce

December 9, 2025

Table of Content

Qianhe Soy Sauce Production Process

Qianhe adopts the traditional high-salt dilute-state brewing process combined with modern bioengineering technology to build an automated and refined soy sauce production system. The whole process follows the core logic of “raw material selection – koji making – fermentation – oil extraction – refining – quality inspection” to ensure product flavor and safety. The detailed production process is as follows:

Raw Material Selection and Pretreatment

Strict Material Sourcing Standards

High-quality core raw materials such as non-genetically modified soybeans from Northeast China, high-quality wheat from Henan, and Zigong well salt are selected. Each batch of soybeans must pass more than 200 indicator tests including protein content and grain plumpness. After unloading and mechanical impurity removal, the raw materials are sent to circular silos for sealed storage to avoid moisture and deterioration.

Step-by-Step Raw Material Processing

Soybeans: After being cleaned in bean washing tanks, they are sent to automatic continuous steaming machines and steamed for about 12 minutes under temperature and pressure controlled conditions to achieve full softening, facilitating subsequent enzymatic hydrolysis

Wheat: Its aroma is stimulated by low-temperature roasting in wheat roasting machines, and after being cooled to an appropriate temperature by cooling machines, it is crushed to provide a loose material foundation for the koji making process.

Koji Making Process

Material Mixing and Inoculation

The crushed and cooled wheat is evenly mixed with the steamed and softened soybeans in a specific ratio, and high-quality Aspergillus oryzae strains are inoculated. The entire mixing process is carried out under sterile conditions to ensure strain purity.

Intelligent Constant-Temperature Cultivation

The mixed materials are sent to intelligent disc koji-making machines with a single tank capacity of 35 tons, and the 16-meter-diameter discs rotate slowly to spread the materials evenly. Cultivated for about 42 hours in a constant temperature environment, koji with dense hyphae and sufficient enzyme activity is formed, providing key biological enzymes for the fermentation process.

Multi-Stage Temperature-Controlled Fermentation

Fermentation Tank Inoculation and Sealing

After the koji is fully mixed with the prepared salt water, it is transported to fermentation tanks through sealed pipelines to avoid external pollution throughout the process. The fermentation cycle is set according to product positioning: 180-380 days for conventional products and up to 560 days for high-end products.

Staged Fermentation Technology

Low-temperature aroma locking stage: Sealed fermentation at 5℃ to retain natural aroma substances of raw materials.

Medium-temperature flavor enhancement stage: Heating up to 30℃ for fermentation to promote enzymatic hydrolysis reactions and generate flavor substances such as amino acids.

Natural maturation stage: Restoring natural temperature in the later stage to allow full integration of flavor substances and improve the mellow taste of the soy sauce mash.

Pressing, Extraction and Grading

Automatic Spreading and Pressing

The mature soy sauce mash is sent to automatic spreading and pressing machines, evenly spread on 1,380-meter-long special filter cloths, which can be folded up to 650 layers. A combination of “natural flowing + graded pressing” is adopted to gently extract crude soy sauce oil, avoiding loss of flavor substances.

Crude Oil Selection for High-End Products

For high-end zero-additive soy sauce, only the first-run crude oil (accounting for 80% of the total) that flows out naturally is selected, which has high purity and rich flavor, ensuring product quality from the source.

Refining and Bottling Process

Sterilization and Filtration

High-temperature instantaneous sterilization: Physical sterilization technology is adopted to kill harmful bacteria and terminate fermentation without damaging the inherent flavor of soy sauce.

Multi-stage filtration: Tiny impurities are removed through precision filtration to make the soy sauce clear and transparent, enhancing the sensory experience.

Aseptic Filling Operation

The refined soy sauce is filled, capped, labeled and other processes completed by aseptic filling equipment in a Class 1000 clean environment. The entire process is controlled automatically to avoid secondary pollution and ensure the hygiene and safety of finished products.

Three-Level Quality Inspection and Storage

Full-Process Quality Inspection System

A three-level inspection system of “raw material incoming inspection – production process inspection – finished product outgoing inspection” is implemented. Internal control standards for pollutants such as heavy metals are much stricter than national standards to ensure that each batch of products is qualified.

Finished Product Storage Management

Qualified products are labeled and then sent to standardized warehouses for classified storage. The warehouses maintain appropriate temperature and humidity and avoid direct sunlight to ensure the quality stability of products before circulation.