Steamed buns are part of the traditional street scene in the Philippines. Countless cookshops, food stalls and bakeries offer this delicious finger food. The sweetish yeast dumplings are at their best when they come fresh and fluffy out of the steamer. The Filipinos often treat themselves to a little bite from the bun on the spot, at their favorite stall, and have the rest packed for eating in the office or at home.

Philippine food is a culinary mix of European and Asian elements. Besides Spanish and Portuguese influences dating back to the colonial era, it is largely a Chinese-type food that dominates eating habits. Therefore, it is not surprising that the Filipinos acquired their enthusiasm for filled steamed buns from South Chinese immigrants: siopao is a Philippine adaptation of the Cantonese “char siu bao” dumpling.

One of the peculiarities of siopao is the recipe: whereas, in the north of China, the dough is prepared solely with yeast, the South Chinese and thus the Philippine variants contain both yeast and baking powder. It is the combination of these two raising agents that gives the dough its characteristic soft, tender texture. Another special feature is the sugar content: North Chinese steamed buns like chiang mian mantou and the filled variant baozi, which is especially popular in the south, are usually made without sugar. But the Filipinos like their bun sweeter and add around 15% sugar to the recipe — which is usual for mantou in the south of China, too.

Artistic pleating

Filipino consumers have a precise idea of how a perfect steamed bun should look: they expect an attractive volume, a white surface and a fine crumb structure.

When shaped by hand, siopao dumplings are often veritable works of art. The balls of dough are rolled out until perfectly circular, and the center is filled with forcemeat. The edges of the dough are then carefully gathered together into little pleats, which are then twisted slightly and sealed as a rosette at the top.

In industrial production, unique specimens of this kind are not desirable. Uniformity is the order of the day. Mechanically filled doughs typically have a symmetrical, round shape and a smooth, even surface.

Color and dough structure

The quality of the steamed buns depends to a large extent on the flour used. Some recipes include rice flour, but generally wheat flour is used since it gives the dough a softer crumb and a better flavor.

All-purpose flour is commonly used to make siopao. It contains about 11% protein and has a gluten index of at least 95%. A higher protein content could cause the dough to shrink, whereas flour with too little protein often results in sticky doughs with a tough bite.

All-purpose flour in the Philippines is made by extracting specialty or patent streams of flour from hard wheat flour milling. Furthermore, the extraction rate must be adjusted precisely to the required product attributes. Moreover, the ash content of the flour is about 0.4% to ensure the dumplings do not have dark specks or a greyish shade.

An unusual feature of milling in the Philippines is bleaching. In contrast to many other countries, bleaching is still permitted in this Southeast Asian archipelago. Most of the all-purpose flours are bleached through chlorination and/or addition of bleaching agent (benzoyl peroxide). Although this form of flour treatment is questionable for health reasons, bleaching offers several advantages in respect to baking. Chlorine and its derivatives are highly functional oxidizing agents that have a considerable effect on the starch, protein and fat constituents of the flour. On one hand they brighten the color of the flour, and on the other they improve the volume of steamed buns and result in a finer crumb structure.

Fluffy dough and savory filling

Besides a tender pastry case, Philippine consumers expect a succulent, savory filling. There are no limits to creativity: every cook swears by his own recipe, seasoning and preparation method.

The list of favorites is topped by fillings made with pork. The classic variant siopao “asado” often uses grilled belly of pork spread with honey. Siopao “bola-bola” contains boiled minced pork. For “sausage” fillings, hot-spicy sausages like chorizo are needed. And in the chicken version, of course, the savory forcemeat is based on chicken.

The meat fillings often are augmented with slices of boiled duck eggs.

In all variants, the indispensable condiment is soy sauce. The fillings are given their individual touch with a variety of flavorings and spices: brown sugar, ginger, toasted sesame oil, or oyster, tamarind or hoisin sauce.

Unlike the filling of a steamed bun, the pastry case does not have such a diversity of ingredients. The following is a standard recipe for siopao dough using a straight method:

Flour: 100%

Yeast: 1%

Baking powder: 1% to 2 %

Salt: 1%

Sugar: 16% to 18 %

Shortening: 4%

Water: ca. 48% to 50 %

After mixing all the ingredients together with the flour, using a straight dough method, the dough is fermented for about 1.5 hours at 32 °C and 82% RH. The fermented dough is sheeted (e.g. in a dough breaker) until it becomes smooth. The dough sheet is then hand-rolled into a cylindrical shape and cut into small pieces of approximately 50 grams. These dough pieces are rounded by hand and left to rest for another 10 minutes in the fermentation cabinet. After resting, each dough piece is flattened with the palm of the hand and sheeted into a 7.5-centimeter circular piece by rotating and making the edges thinner than the center. About 1.5 tablespoons of filling is placed in the center of the dough piece. The filling is sealed in by pinching and pleating the edges of the dough together.

Each bun is placed on a rectangular piece of wax paper in a steamer and proofed for 45 minutes (32 °C, 82% RH). The buns are then steamed for about 10 minutes or until fully cooked.

Steaming challenges

Whichever method is used for preparing the dough, steaming remains the most difficult part of siopao production. Since the yeast dumplings are not baked at high temperatures, unlike bread, they do not form a hard crust to stabilize the product, so steamed buns are constantly in danger of collapsing during and shortly after production.

The challenge to every cook is to conjure a soft, fluffy snack out of the steamer that maintains its proper shape and has neither wrinkles nor blisters nor cracks.

Enzymes as quality boosters

Whereas many quality parameters of siopao production can be controlled manually in the purely artisan sector, industrial production demands standardized raw materials with uniform product attributes. In this connection, flour treatment becomes increasingly important. Through the carefully adjusted interplay of enzymes and additives, it is possible to control and specifically optimize quality-relevant criteria such as fermentation stability, volume, color, crumb structure and bite.

The following is an overview of the most common faults in products and tried-and-tested ways of preventing them in the production of siopao doughs:

Problem: Shrinkage and collapse.

Possible cause: Strong flour, dough under or overdeveloped, steamer pressure too high, steamer temperature too low, sprout-damaged wheat.

Solution: Select correct and sound wheat, correct steamer pressure and temperature, add lipase to improve stability and hemicellulase for extensibility (e.g. Alphamalt LP & EFX series, Alphamalt HC series.)

Problem: Blisters.

Possible causes: Soft dough, proofer humidity too high, over proofing, water dripping on the skin, steamer pressure too high.

Solution: Reduce added water, control proofer humidity, control proofing time, prevent water from dripping on the skin, reduce steamer pressure. Add lipase (e.g. Alphamalt LP & EFX series) or emulsifier (e.g. Mulgaprime SSL) to improve dough stability.

Problem: Wrinkles on the skin.

Possible causes: High protein flour with very strong dough properties.

Solution: Adjust flour quality, weaken the gluten with softening treatment (e.g. EMCEsoft P10, EMCErelax).

Problem: Yellowish color.

Possible causes: High ash content, higher protein, wrong wheat type, poor dough development, over-proofing, alkaline pH.

Solution: Use flour with a lower extraction rate, control proofing time, add lipase and emulsifier (e.g. Alphamalt LP & EFX series, Tigerzym series, Mulgaprime SSL), reduce sodium bicarbonate.

Problem: Very open crumb.

Possible causes: Over-fermented dough, high amylase activity.

Solution: Reduce proofing time, reduce the amount of sugar in the recipe. Add lipase (Alphamalt LP & EFX series), add sodium bicarbonate, add emulsifier (e.g. Mulgaprime SSL).

Problem: Surface cracks.

Possible causes: Hard dough properties, low elasticity.

Solution: Increase added water, increase proofer humidity, add hemicellulase (e.g. Alphamalt HC series) or softening agents (e.g. EMCEsoft P10, EMCErelax).

Problem: Poor flavor.

Possible causes: Fast dough preparation, short time for resting and proofing.

Solution: Extend preparation time, switch to traditional methods with sour or sponge dough.

Problem: Compact and/or small volume.

Possible causes: Not enough yeast, hard dough, under-proofing.

Solution: Increase yeast dosage, increase added water, extend proofing time, add alpha-amylase, lipase and hemicellulase to make the dough manageable and extensible (e.g. Alphamalt VC 5000, Alphamalt LP & EFX series and Alphamalt HC series).