小火 (Low Heat)
Pinyin: xiǎo huǒ
Definition
Xiao huo is the lowest effective heat setting, typically 200-275°F (95-135°C) surface temperature, used for slow simmering, rendering fat, and gently infusing flavors. It produces barely visible bubbles in liquids — a gentle simmer rather than a rolling boil. Xiao huo is essential for Chinese soups (tang), congee (zhou), and slow-braised dishes where extended cooking time breaks down collagen into gelatin.
Stove Parameters
Gas
Smallest stable flame, about 15-20% of maximum
Turn the gas down until the flame is small but steady — typically 0.5 inches tall. If the flame flickers or threatens to extinguish, it is too low. Some home burners cannot maintain a stable xiao huo; use a heat diffuser plate if needed.
Induction
Power level 2-3 (400-700W)
Induction is excellent for xiao huo because it can maintain very low, stable temperatures without flame-out risk. Set to power level 2-3. Some induction units cycle on/off at low settings — choose one with continuous low-power mode if possible.
Electric
Setting 2-3 out of 10
Electric coils retain heat well at low settings, making them surprisingly effective for xiao huo. Set to low and allow 2-3 minutes to stabilize. The residual heat in the coil helps maintain a steady gentle simmer.
Ceramic
Setting 2-3 out of 9 or 10
Ceramic cooktops hold low temperatures evenly. Set to low and let it stabilize. The glass surface distributes heat well, reducing hot spots that could cause uneven simmering.
Common Mistakes
- Setting the heat too low so the flame goes out (gas) or the induction unit cycles off — xiao huo must maintain a continuous gentle simmer
- Lifting the lid frequently during xiao huo cooking, releasing trapped steam and extending cooking time by 10-15 minutes each time
- Using xiao huo for stir-frying, which causes food to release moisture and stew instead of developing crispy texture
- Not using enough liquid for long xiao huo sessions — check water level every 30 minutes for simmering dishes
FAQ
How long can I cook on xiao huo?
Xiao huo cooking can last from 20 minutes to 4+ hours depending on the dish. Congee (rice porridge) simmers for 45-90 minutes. Bone broth simmers for 2-4 hours. Red-braised pork belly (hong shao rou) simmers for 60-90 minutes. Always ensure there is enough liquid to prevent burning — maintain at least 1 inch of liquid above the ingredients.
What does xiao huo look like in the liquid?
At proper xiao huo, the liquid surface should show small, lazy bubbles rising from the bottom every 2-3 seconds — what Western cooking calls a bare simmer. If you see continuous rapid bubbling, the heat is too high (closer to zhong huo). If there are no bubbles at all, the heat is too low to cook effectively.
Should I use a lid when cooking on xiao huo?
Usually yes, but it depends on the goal. Use a lid when you want to retain moisture (soups, congee, braised dishes). Leave the lid off when you want to reduce and concentrate a sauce. For some dishes, a partially offset lid creates the perfect balance — retaining some steam while allowing gentle evaporation.