Hardness and Oil Content of Sweet Fillings (Red Bean, Mung Bean, Taro Paste, Lotus Seed Paste)

Mooncakes, sun cakes, red bean buns, taro pastries, and mung bean pastries: Taiwanese pastries and Chinese-style snacks cannot do without sweet fillings. Sweet fillings may look simpler than meat fillings, but they demand just as much care on a machine: too soft and they slump and leak, too much oil and they slip, too firm and they will not feed.

What Condition Should Sweet Fillings Be In for Machine Production?

Sweet fillings that run well on a machine have roughly these characteristics:

• Hold their shape: A rolled ball does not spread when left to sit, and the cut face is clean after cutting.
• Not sticky to the touch: Touching the surface does not leave your hand covered.
• No oil seepage: After sitting for a while, no ring of oil seeps out underneath.
• Consistent firmness: The same batch has about the same firmness from start to finish.

What to Do When Bean Paste Is Too Soft

Common causes of overly soft bean paste are that the water was not cooked off fully, the proportion of sugar or water is too high, or it has warmed up too much. Solutions:

1. Cook it down further: Homemade filling can be cooked a while longer to reduce the water, stirring constantly to keep it from scorching on the bottom.
2. Chill to set: Sweet fillings firm up when chilled; before going on the machine, take out a small amount and let it warm to a workable state.
3. Load small amounts frequently: Avoid letting a whole tub of filling slowly soften in the work area.

When filling is too soft, the weight of portions cut on a dividing machine is unstable, and during encrusting it tends to squeeze out of the seal; see Inconsistent Piece Weight and Leaking and Exposed Filling.

Will Oily Fillings Slip on the Machine?

Yes. Fat is an important source of texture and shelf life in sweet fillings, and lotus seed paste, taro paste, and jujube paste often contain a lot of oil. But with too much oil:

• The filling tends to slip in the feed screw or piston, so the feed amount is unstable.
• The wrapper and filling do not stick together, and the seal tends to seep oil and open up.
• As the temperature rises, the fat softens and the whole filling becomes soft.

The approach is to control the oil content within what the recipe allows, let the oil be fully absorbed during cooking, and chill so the fat solidifies before going on the machine. For the relationship between fat and temperature, see also Filling Temperature: Why Fillings Are Often Chilled Before Going on the Machine.

Homemade vs. Commercial Fillings

Commercial fillings are produced by filling manufacturers with specifications for firmness, sweetness, and oil content, and little variation between batches, making them suited to mass production where consistency matters; the drawback is that it is harder to create a signature flavor, and you have to choose from the manufacturer's specifications. Homemade fillings let you create your own flavor, but the cooking time, heat, and bean lot of each pot all affect firmness, so stricter operating standards are needed: weigh to a fixed recipe, fix the cooking time and how the end point is judged, and ideally measure and record the firmness or moisture of every batch.

Either way, whenever you switch to a new batch of filling, we recommend running a small batch on the machine first to confirm.

Which Sweet Fillings Can Dong-Yih's Machines Handle?

Dong-Yih Machinery's DY-528MS Sweet Potato Ball and Taro Ball Dividing Machine and DY-528M Automatic Dough and Filling Dividing Machine are suitable for mooncake filling, mung bean paste, red bean paste, sun cake filling, Dajia pastry filling, taro pastry filling, and more, with an output of 3,000–12,000 pieces/hour at 10 g–30 g per piece or heavier. To find out whether your sweet filling can run on the machine, bring a sample and call 06-257-4644.

FAQ

Q: What happens when red bean paste that is too soft goes on the machine?
A: Divided weights are unstable, and during encrusting it tends to squeeze out of the seal; you can cook it down or chill it to set before running it.

Q: Will oily fillings slip?
A: Yes: the feed amount becomes unstable and the seal will not stick. Controlling the oil content and chilling so the fat solidifies before going on the machine is more reliable.

Q: What is the difference between homemade and store-bought filling?
A: Commercial filling has consistent specifications and little batch variation; homemade filling has a distinctive flavor, but batch variation must be controlled with a fixed recipe and cooking standards.

Q: Which Dong-Yih machines can divide mooncake filling and mung bean paste?
A: Both the DY-528MS and DY-528M are suitable for dividing mooncake filling, mung bean paste, red bean paste, and other fillings.