The core reasons why dried bean curd sticks break easily can be grouped into four main categories: abnormal moisture content, processing defects, improper storage conditions, and issues with raw materials or formulation.
I. In-Depth Analysis of the Core Causes
1. Imbalanced Moisture Content
The crispness and toughness of beancurd sticks depend on the balance between moisture and protein. Excessively high or low moisture levels will both lead to brittleness.
Moisture too low (<8%):
When fuzhu is overly dried, the protein molecules bind too tightly, leaving little elasticity or cushioning, making the product prone to breaking under pressure.
Examples:
Drying temperature too high (above 80°C) or drying time too long, causing rapid internal moisture loss and a brittle structure.
During natural air-drying, overly strong ventilation or direct sunlight dries the surface too fast while the inside remains moist, forming a hard, uneven structure. As residual internal moisture continues to evaporate during storage, the product becomes increasingly brittle.
Moisture too high (>12%):
When the moisture content exceeds the standard, mold growth or oxidation can occur during storage, causing protein degradation and structural weakening, which makes fuzhu fragile.
Examples:
Incomplete drying, leaving moisture trapped inside.
Insufficient cooling before packaging, causing condensation inside the packaging and secondary moisture absorption.
2. Processing Defects
Low soy milk concentration or insufficient protein content:
- Fuzhu is mainly composed of soybean protein. If the soy milk concentration is too low or the protein content is insufficient, the resulting protein network will be loose, yielding poor toughness and easy breakage.
- If the cooking temperature of the soy milk does not reach above 95°C or the holding time is insufficient, the proteins cannot fully denature and form a stable gel network.
- If the film formed at the surface is too thin when lifted, structural strength is inadequate.
- Lifting the film too quickly can create micro-cracks that become brittle after drying.
3. Improper Storage Conditions
Unsuitable temperature and humidity:
If storage temperature is too high (>25°C) or humidity too low (<40%), fuzhu continues to lose moisture. Hydrogen bonds between protein molecules break down and the structure becomes brittle.
If humidity is too high (>60%), moisture absorption and mold growth occur, leading to localized brittleness and powdering.
Excessive vibration during transport:
Without adequate cushioning, collision and compression during transport cause mechanical damage, increasing the likelihood of breakage later.
4. Raw Material Quality Issues
Poor-quality soybeans:
Using soybeans stored for more than one year, deteriorated beans, or varieties with protein content below 40% results in insufficient protein activity. This prevents formation of a strong protein network, weakening the toughness of fuzhu.
Excess impurities:
If filtering is inadequate and soy pulp residues remain, these impurities disrupt the continuity of the protein network, creating weak points inside the fuzhu that can easily break.
II. Solutions
1. Improve Production Processes
Moisture control: Maintain drying temperatures between 60–70°C and dry in stages (65°C initially, 60°C later). Ensure final moisture content is 8%–10%. Cool to room temperature (<25°C) before packaging to avoid condensation.
Optimize raw materials and formulation: Use high-quality soybeans with protein content ≥42%. Maintain soy milk solids at 12%–15%. Add 5%–8% cornstarch and disperse it evenly.
Standardize processing: Heat soy milk to ≥95°C and hold for 15–20 minutes. Control film thickness to 0.3–0.5 mm and lift the film steadily to avoid tearing.
No additives: Our company's fuzhu contains no additives.
2. Improve Storage and Transportation
Storage: After sealing, store in a cool, dry place (15–20°C, 45%–55% humidity), avoiding direct sunlight and heat sources.
Transportation: Use cushioning materials (bubble wrap, EPE foam), avoid excessive stacking, and minimize vibration and compression.
3. Recommendations for Purchasing and Use
Purchasing: Choose products with intact, airtight packaging and no off-odors. Check color and texture; avoid products that look overly white, feel brittle, or shed powder easily.
Before use: Fuzhu must be rehydrated before cooking.
The fundamental reason dried beancurd sticks break easily is the disruption of the protein network structure. Moisture imbalance and improper processing are the primary triggers, while storage conditions and raw material quality amplify the issue. Our company improves fuzhu quality through optimization of raw materials, production processes, and moisture control.
Shuangqiang Premium Fuzhu - committed to zero additives for 25 years. Our company integrates production, sales, and R&D, specializing in a wide range of soy products. We also offer customized solutions based on customer requirements. If you are interested in purchasing Fuzhu or other soy products, please email us at info@sqsoyproducts.com. We will reply as soon as possible.