Machine Production of Mooncakes, Egg Yolk Pastries, and Mung Bean Pastries

Every year, in the two to three months before the Mid-Autumn Festival, pastry makers face the greatest pressure on capacity. Mooncakes, egg yolk pastries (蛋黃酥), and mung bean pastries (綠豆椪) have different structures: Cantonese mooncakes are syrup dough wrapped around filling and then pressed in a mold, while egg yolk pastries and mung bean pastries use a flaky crust (water dough wrapped around oil dough) around the filling. They also differ in how easily they can be mechanized.

Can Mooncakes Be Made with an Encrusting Machine?

Yes. The structure of a Cantonese mooncake is "crust wrapped around filling (optionally with a salted egg yolk inside)," formed first into a ball and then pressed into a mold to set its shape. The first half is exactly the job of an encrusting machine.

The mooncake page on the website of Japan's RHEON lists models including the universal encrusting machine KASEIJIN (火星人) CN700, the compact confectionery CN050, the encrusting and panning AN210, and the two-row WN155; the product list for the KN551 on its U.S. website also includes Moon Cake and the Middle Eastern Ma'amoul. This shows that encrusting mooncakes is a common application for encrusting machines.

Key points for machine production:

• Crust-to-filling ratio: Cantonese mooncakes have thin crusts and lots of filling, so the crust needs good extensibility.
• Firmness of the syrup crust: Invert syrup crust needs to rest; too soft and it sticks, too firm and it cracks.
• Firmness of the filling: Lotus seed paste, bean paste, jujube paste, and other fillings should be close in firmness to the crust so the crust comes out even.

What Option Is Needed to Wrap a Whole Egg Yolk?

A salted egg yolk is a "solid" and cannot be extruded like filling. To wrap whole egg yolks, an encrusting machine usually needs an additional solid-ingredient feeder that places the yolks one by one into the center of the filling. RHEON's Asia-Pacific website has a "Smart Solid Feeder" described as automatically supplying egg yolks; its Japanese website also lists a "solid-ingredient encrusting unit" (固形物包あん装置, which feeds solids into the encrusting machine).

Without a solid-ingredient feeder, some makers first wrap the egg yolk in filling by hand to make "filling balls," and then let the machine wrap the crust. Which method is right depends on output and staffing.

How Is the Mold Press Connected?

What comes out of the encrusting machine is a round ball; the pattern and shape of the mooncake come from the mold press:

• Manual mold pressing: The ball is placed in a wooden or plastic mold, pressed firmly, and knocked out.
• Automatic mold pressing: The balls travel on a conveyor to a mold-pressing device, are imprinted with the pattern, and are panned. The equipment listed for the KN551 on RHEON's U.S. website includes peripherals such as a Heat Stamper and Set Panner (automatic panning).

The size and firmness of the balls must be consistent before pressing, or the patterns will be unclear and the edges will overflow. After pressing, they are panned, brushed with egg wash, and baked.

Can Flaky Crusts Run on a Machine?

For flaky pastries such as egg yolk pastries, mung bean pastries, and sun cakes, the crust is made of "water dough" wrapped around "oil dough," then rolled out and rolled up to create layers. Approaches to mechanization include:

• Using an encrusting machine or a two-layer feeder to wrap the oil dough in the water dough, then sheeting and rolling it to create layers, and finally wrapping the filling.
• Simplifying the layering in the recipe so the crust can be wrapped directly in one pass on an encrusting machine.

The difficulty with flaky crusts is that the oil dough softens with temperature, and the layers are easily crushed. The temperature of the work environment and the type of fat both affect the results. The most reliable way to find out whether you can achieve the layering you want is still to bring your recipe for a test run.

Dividing the Filling

However the crust is wrapped, the filling must first be portioned. The suitable products listed on Dong-Yih Machinery's website for both the DY-528MS Taro Ball and Sweet Potato Ball Dividing Machine and the DY-528M Automatic Dough and Filling Dividing Machine include mooncake filling, mung bean paste, red bean paste, and taro pastry filling, with an output of 3,000–12,000 pieces/hour at 10 g–30 g per piece or heavier. The mung bean filling for mung bean pastries and the red bean filling for egg yolk pastries can both be portioned on the dividing machine first, then go on to the crust-wrapping process.

For pineapple cakes and sun cakes, see Machine Production of Pineapple Cakes, Sun Cakes, and Flaky Pastries.

FAQ

Q: Can mooncakes be made by machine?
A: Yes. A mooncake is a ball of crust around filling that is then pressed in a mold; an encrusting machine can handle the first part, followed by mold pressing and panning.

Q: What equipment is needed to wrap salted egg yolks?
A: A solid-ingredient feeder that places the yolk in the center of the filling. Without one, you can wrap the yolk in filling by hand first and then let the machine wrap the crust.

Q: Can a machine make the layers in egg yolk pastry crust?
A: An encrusting machine can wrap the oil dough in the water dough, which is then sheeted and rolled to create layers, but oil dough is temperature-sensitive, so confirm through a test run.

Q: Can Dong-Yih's machines make mooncakes?
A: The suitable products listed on Dong-Yih's website for the DY-528MS and DY-528M include dividing mooncake filling, mung bean paste, red bean paste, and other fillings. For crust wrapping and mold pressing, please call 06-257-4644.