Egg Waffle — Hong Kong bubble waffle

i. Origin & history

Egg waffles are a product of Hong Kong's street-food culture of the mid-twentieth century, usually dated to around the 1950s, when hawkers cooked them over charcoal stoves in hand-held cast-iron moulds and sold them hot in paper bags. Nobody knows who made the first one. The most popular story says vendors began making them with cracked or unsellable eggs from grocers; another says the egg-shaped cells were a way of making something that looked like eggs at a time when real eggs were expensive. Both are traditions rather than documented history, but they agree on the spirit: a cheap, filling, sweet snack from simple ingredients.

The name gai daan zai (雞蛋仔) is affectionate: gai daan means chicken egg and zai means small or little. In English the snack has many names — egg waffle, egg puffs, eggette and, especially in Britain and North America, bubble waffle.

As Hong Kong changed, the charcoal hawkers largely disappeared, replaced by small shopfronts with gas or electric irons. Egg waffles became a symbol of the city's street food and of nostalgia for older Hong Kong, alongside milk tea, pineapple buns and fishballs. The best are still cooked to order and eaten walking down the street.

From the 2010s, egg waffles spread internationally in a new form: folded into a cone, filled with ice cream, fruit, sauces and sweets, and photographed endlessly. That bubble-waffle cone began as a Hong Kong dessert-shop variation and is now found from London to Sydney. The plain original, eaten hot, is the one Hong Kong people mean by gai daan zai.

ii. How each bubble gets a crisp shell and a soft centre

The texture people prize in egg waffles is a thin, crisp, golden shell around each bubble, with a soft, chewy, slightly hollow centre. Three things create it: starch, fat and a very hot iron.

The batter is a lean pancake-like batter enriched with eggs and evaporated milk, but a part of the flour is replaced with tapioca starch or potato starch. Starches have no gluten and crisp up hard as they dry in the heat, so they give the shell its crunch, while tapioca adds a slight chew to the centre. Custard powder, a Hong Kong favourite, adds vanilla flavour, a yellow colour and more starch. Evaporated milk gives the characteristic milky, caramel-tinged flavour of Hong Kong snacks.

The iron must be very hot before the batter goes in. The cells are filled almost to the top, the iron is closed and immediately flipped, so the batter runs into the other half and fills it. The surface touching the metal sets instantly into a shell, and the steam generated inside each sphere puffs it up, leaving the centre partly hollow. Cooks keep turning the iron during cooking so both sides brown evenly.

Finally, egg waffles go soft quickly as steam escapes from the inside into the shell. Professional vendors lay them on a wire rack, or toss them briefly in the air or fan them, so the steam escapes rather than condensing on the crust. A resting time for the batter — at least 30 minutes, ideally an hour — lets the flour hydrate and the bubbles from mixing settle, giving smoother, rounder spheres.

iii. Ingredients

Makes 4 servings · scroll the side panel to adjust

• 150 g plain flour
• 30 g tapioca starch
• 15 g custard powder
• 1½ tsp baking powder
• 100 g caster sugar
• 1 pinch of salt
• 2 eggs
• 150 ml evaporated milk
• 100 ml water
• 30 ml neutral oil, plus extra for the iron
• 1 tsp vanilla extract

You need an egg-waffle iron: a hinged stovetop pan with rows of hemispherical cells, or an electric bubble-waffle maker. Tapioca starch gives the crisp shell and slight chew; potato starch or cornflour also work. Custard powder is optional but gives the classic Hong Kong flavour and colour; replace it with more flour if you don't have it. Evaporated milk is traditional; whole milk is fine but less rich. Oil keeps the waffle crisper than butter, which browns faster and softens the crust.

iv. Method

1. Whisk the flour, tapioca starch, custard powder, baking powder, sugar and salt in a bowl.
2. In a jug, beat the eggs, then whisk in the evaporated milk, water, oil and vanilla.
3. Pour the wet into the dry and whisk just until smooth. Strain into a jug, cover and rest for 30–60 minutes at room temperature.
4. Heat the egg-waffle iron over medium heat for 3–4 minutes on each side until very hot; a drop of water should sizzle away at once. Brush both halves lightly with oil.
5. Stir the batter. Pour it into the lower half to fill all the cells and lightly cover the flat areas between them. Close the iron and immediately flip it over.
6. Cook for 2 minutes, then flip and cook for 2–3 minutes more, flipping every 30 seconds or so towards the end, until both sides are deep golden. Open to check.
7. Turn the waffle out onto a wire rack and leave it for 30 seconds to 1 minute to let steam escape and the shell crisp. Repeat with the rest of the batter, oiling the iron each time.

v. Tips & common mistakes

• Get the iron really hot. A lukewarm iron gives pale, soft, flat waffles. The batter should hiss as it goes in.
• Flip immediately after closing. This sends batter into the top half of each cell to make complete spheres instead of half domes.
• Rest the batter. Freshly mixed batter gives uneven, bubbly-skinned spheres; rested batter cooks smoother and rounder.
• Season a new iron. Cast-iron moulds need oiling and heating before first use, or the first few waffles will stick.
• Cool on a rack, not a plate. Steam trapped against a plate turns the crisp shell soft within a minute.
• Eat them straight away. Egg waffles are at their best in the first five to ten minutes; they cannot be held for long.

vi. Variations

Hong Kong shops sell chocolate, matcha, sesame, coconut and pork floss and seaweed egg waffles, as well as versions with chocolate chips or cheese melted into the bubbles. Bubble waffle cones fold the hot waffle round a cone and fill it with ice cream, fruit and sauces. Taro and purple sweet potato versions are popular in Taiwan and Southeast Asia.

Other street snacks cooked in shaped irons include Korean fish-shaped bungeoppang and Japanese monaka wafers; for a Western waffle, compare thick, yeasted Belgian waffles and the pastry hybrid croffle.

vii. Serving & storage

Serve egg waffles hot from the iron, loosely folded into a paper bag or cone, and eat them by tearing off the bubbles. In Hong Kong they are a walking snack, often paired with a cup of milk tea. For a dessert, fold a hot waffle round a scoop of vanilla, mango or matcha ice cream with fruit and a drizzle of chocolate or condensed milk.

They are best within minutes. Leftovers soften but can be re-crisped in a hot oven or air fryer at 180°C (160°C fan, 350°F) for 3–4 minutes. The batter keeps covered in the fridge for up to a day; let it come back to room temperature and stir before cooking.

ix. More from Chinese

• Red Bean Bun — steamed sweet bean bun
• Tangyuan — glutinous rice balls
• Pineapple Cake — Taiwanese shortbread pastry
• Bungeoppang — Korean fish-shaped pastry
• Croffle — croissant waffle
• Belgian Waffles — deep-pocketed waffles