Siu Mai (Open-Topped Pork and Prawn Dumpling)

Variations

• Japanese shūmai: pork only, no prawn, with a single pea pressed into the top. It became a Yokohama speciality and then a lunchbox staple — smaller and softer than the Cantonese kind.
• Shanghai siu mai: filled with glutinous rice instead of meat. The same name for what is effectively a different dish, and a surprise if you order it expecting this one.
• Northern shao mai (稍麥): around Hohhot it is lamb and spring onion in a thicker wrapper, opening into a wide flower at the top. It does not even look like the yellow-wrapped Cantonese version.
• Salt and pepper siu mai: steamed, then deep fried and dusted with salt and white pepper — a Hong Kong snack-shop item.
• Instead of crab roe: carrot, peas, sweetcorn. The topping is there for colour, so it changes very little.
• Freezing: shape them and freeze unsteamed, spread on a tray before bagging, then steam from frozen for 12 minutes. Steamed first and then frozen, the wrapper toughens on reheating.

Tips

• Do not close the top. This is the most common misunderstanding the first time. A siu mai is a cup made of wrapper, not a sealed dumpling, and the filling showing at the top is correct. Har gow is pleated shut, xiaolongbao is twisted shut to hold soup in, and gyoza is pressed shut to be pan-fried. Dumplings that arrive on the same table are solving different problems.
• Its wrapper works on the opposite principle to har gow's. A har gow wrapper is wheat starch scalded with boiling water so the starch gelatinises — translucent, and with no gluten at all. Siu mai uses an ordinary gluten wheat-and-egg wonton wrapper as it comes. Side by side on a trolley, they are completely different doughs (dough and gluten).
• Salt first, then slap it. Same mechanism as menchi katsu with a different goal: there it is to stop the patty falling apart, here it is to build a filling that springs back when you bite it. The difference is how far the same principle is pushed (salt and seasoning).
• 25–30% fat is not negotiable. Siu mai made with lean pork is dry, and no amount of extra seasoning fixes it. The easy route is asking the butcher to mince shoulder.
• Use the mushroom soaking water. It gives more depth than plain water or stock, and two tablespoons is all you need. Pour it off the grit that settles at the bottom (soaking).
• Prawns last, and coarse. Minced with everything from the start they disappear into the pork. Keeping half of them in rough pieces is the trick.
• Keep the steamer at a hard boil. Weak steam leaves the wrapper slack and undercooked (dry heat and moist heat).
• Stop at 8–10 minutes. This is not a thing that improves with longer steaming: the wrapper toughens and the filling gives up its juice into the basket.
• Origin: an early trace is usually placed in the teahouses of Hohhot, recorded as 稍麥, spreading south into the Cantonese dim sum form. Fillings and wrappers differ so much by region (see the variations above) that a single lineage is hard to pin down — but the Cantonese version is what most people now mean by siu mai.