Taste is the core quality of chestnuts. As a key processing step, steaming boiling directly determine the tenderness, sweetness flavor of chestnut flesh. Details including pretreatment, cooking method, temperature & time, pressure, ingredients post-treatment greatly affect the final taste.

1. Pretreatment: Soaking & Slitting

Pretreatment ensures even heating proper moisture.

Soaking: Soak 30–60 minutes in 20–25°C cold water to soften shells, reduce astringency replenish moisture. Under-soaking causes dry, bitter flesh; over-soaking leads to mushy texture. Warm water will make flesh sticky.

Slitting: Cut 1/3–1/2 deep into flesh (straight cross cut) along the thin shell line. Shallow cuts cause bursting; deep cuts damage flesh integrity.

2. Steaming vs Boiling

Steaming: Even steam penetration retains original flavor, delivering soft, grainy texture. Control water volume to avoid excessive moisture uneven heating.

Boiling: Direct water contact creates extra tenderness. Add 5–10% sugar 1–2% oil to improve taste, gloss anti-sticking effect. Keep water 1–2 cm above chestnuts.

3. Temperature & Time

At normal pressure: steam at 100°C, boil at 95–100°C.

For medium-sized chestnuts (15–20g each): steam 25–30 mins, boil 20–25 mins. Improper temperature time results in undercooked, tough overly dense flesh. Judge doneness by gentle pressing.

4. Pressure Control

Normal pressure: Natural layered flavor, longer cooking time.

High pressure (120–130°C): Fast cooking (15–20 mins) with uniform tenderness, ideal for mass production. Release pressure slowly to prevent bursting hardening.

5. Ingredients

Sugar/maltose (5–8%): Lock moisture, boost sweetness gloss.

Salt (0.5–1%): Reduce astringency for fresher taste.

Vegetable oil (1–2%): Prevent sticking smooth texture.

Citric acid (0.1%): Anti-oxidation color retention, no impact on taste.

6. Steeping & Cooling

Steeping: Let stand 10–15 mins after heating for full starch gelatinization balanced moisture.

Cooling: Natural cooling maintains tenderness. Quick cold-water cooling eases shelling but tends to harden flesh (suitable for peeled chestnuts).

All parameters shall be adjusted according to product types (stir-fried, ready-to-eat kernels, canned chestnuts etc.) to achieve ideal taste.