Roti Sai Mai (โรตีสายไหม)

Silk Threads In A Paper-Thin Wrap

The name splits neatly: โรตี for the wrapper, สายไหม — "silk threads" — for the filling, sugar boiled and pulled by hand into a cloud of fine strands. Thai Wikipedia lists the five steps every Ayutthaya producer knows: การหม่าแป้ง (soaking the flour), การแต้มแป้ง (dabbing the wrapper onto the pan), การทำหัวเชื้อ (making the flour-and-oil paste that lets the sugar be pulled), การเคี่ยวน้ำตาล (simmering the sugar) and การดึงเส้นสายไหม (pulling the threads).

The wrapping is the first surprise: the "roti" is not the thick, flaky flatbread that shares the name. Silpa-Mag's title asks the question outright — why is it called roti when it isn't made from roti dough? The answer sits in the dish's history. The sweet arrived with Indian Muslim traders who wrapped the floss in thick roti; the thin wrapper came later, when the floss makers switched to the cheap, quick Chinese popiah sheet (แป้งเปาะเปี๊ยะ). Same wheat flour, but no sugar, no long knead — and, the sources agree, a better match: the plain, faintly salty sheet sets off the sweetness of the floss.

The floss itself is the craft. SGE Thai is blunt: it looks like two ingredients, but pulling two kilos of boiled sugar into thousands of fine threads takes real strength and practice — beginners should expect to train their arms before their first beautiful batch. The reward is a texture no machine matches: the floss is silky rather than airy, faintly chewy, tasting of caramelised sugar rather than spun air.

Ayutthaya kept the craft alive and made it a province brand: roti sai mai is an OTOP product of Tambon Khan Ham, Uthai district, and the floss-and-wrapper stalls that line the roads out of the old capital have turned the sweet into the souvenir every visitor carries home. Krua.co's profile of Bang Din — one of the old-school shops — notes the tell of tradition: the floss comes in a single golden-brown colour, straight from the simmering pan, no dye.

The Recipe (vendor scale, from SGE Thai)

Flavours (SGE Thai): once the pulling is mastered, tint the floss — orange, pandan, cocoa — and work sesame or crushed cashews into the wrapper dough. The old-style look (Krua.co): a single golden-brown floss, uncoloured, exactly as it comes off the simmering pan.

The Method

1. The dough. Mix the flour, salt and tapioca starch, then add the water and oil and knead for 3–5 minutes until it comes together. Rest 15 minutes, knead one minute more — the dough should be smooth and elastic.
2. The wrapper. Heat a flat pan. Take a lump of dough in your hand and dab it onto the pan into a thin round, scraping the excess away with a silicone spatula. When the sheet dries and cooks through, ease it off the edge. Stack the finished sheets — SGE Thai's pan method makes a wrapper far thinner than any rolling pin, and it is what separates this crepe from a roti.
3. The sugar. For the floss: simmer the brown sugar with water until it turns thick and sticky, then pour it into a small aluminium basin sat in cold water. Work the edges towards the middle with a trowel as it cools until the sugar sets into a golden block. Keep it somewhere cool so it doesn't re-melt into a lump.
4. The paste. The head-start (หัวเชื้อ) that makes pulling possible: mix plain flour with vegetable oil, leave it for an hour, then spread it across a large aluminium tray and warm it gently. The paste stops the sugar sticking as it is pulled.
5. The pull. Roll the sugar block into a ring, lay it on the paste tray, and pull with two wooden sticks — stretch, fold back on itself, stretch again. Again and again, until the golden mass splits into fine silky threads. SGE Thai is honest about this step: it is the one that needs strength and patience, and it is where beginners quit.
6. The wrap. Lay a sheet flat, pile a generous handful of floss in the middle, fold the edges over like a wrap. Eat immediately — the floss draws moisture from the air and the wrapper, and a wrapped roti sai mai that sits becomes a soft, sweet sock.

Where Thai Sources Disagree

How Western Versions Get It Wrong

• Cotton-candy machine floss. A machine spins sugar into airy wisps. Sai mai is pulled by hand through a flour-and-oil paste — finer, silkier, faintly chewy, with a caramelised taste the machine never produces. SGE Thai sells cotton-candy machines, and even its sales copy keeps the two apart.
• Thick roti dough. The wrapper is not a roti, despite the name — Silpa-Mag's whole article is built on the point. A thick, flaky flatbread buries the floss; the dish wants a paper-thin sheet that reads more like a crepe than bread.
• Crisping the wrapper. Western recipes grill the sheet until it browns and crisps. The Thai wrapper is cooked just until it sets — soft, pliable and faintly savoury, so the floss can be rolled into it.
• Wrapping ahead of time. Floss and moisture are enemies: wrap the sweet early and the threads collapse into a sticky slab. Every source — and every Ayutthaya stall — assembles at the moment of eating.
• Condensed milk, banana, chocolate sauce. The classic has exactly two components, and the savoury-sweet tension between the plain sheet and the sugar is the point. The Thai elaborations — pandan sheets, sesame dough, tinted floss — stay inside the two-part structure; the loaded-dessert version is an invention.

UK Ingredient Notes

• Brown sugar: UK soft brown or demerara both work; the golden single-colour floss is the traditional look (Krua.co).
• Tapioca starch: at Thai grocers and online Thai supermarkets; it is the stretch in the wrapper.
• The shortcut wrapper: popiah (spring-roll) sheets from any Chinese or Thai grocer — cook them on a dry pan just until set, the way the sources describe the commercial version.
• Ready-made sai mai: boxes of floss at Thai grocers and online — the honest alternative to pulling, and what most Thai home cooks would do.
• Storing (Krua.co): keep the floss in a sealed bag at room temperature; refrigerate the wrapper sheets in an airtight container for up to 5 days and let them come back to room temperature before eating. Always wrap just before serving.

Sources

This recipe is translated from the following Thai-language sources. Where they disagree, we've said so.