How to Adjust the Ratio of Dough to Filling (Encrusting Ratio)

What Is the Encrusting Ratio?

The encrusting ratio refers to how much of a finished piece is filling. Some in the industry express it as "dough : filling," such as 4:6; others simply say "60% filling." Mooncakes and egg yolk pastries aim for thin crusts and lots of filling; for steamed buns (包子) and plain mantou, the texture of the dough matters, so the dough proportion is usually higher. If one machine is to make different products, the ratio has to be adjustable.

Can You Adjust for More Dough or More Filling?

Yes, and this is a basic function of an encrusting machine. The principle was covered in the co-extrusion article: the dough and filling each have their own feed system, each controlled by a motor. With the weight per piece held constant:

• Speed up the dough feed and slow down the filling → thicker dough, less filling.
• Slow down the dough and speed up the filling → thinner dough, more filling.

The total feed volume determines how much each piece weighs, and the ratio between the two determines the dough-to-filling ratio. Newer machines handle this from the control panel: on RHEON's KASEIJIN (火星人) CN700, you simply enter the number of pieces, the dough weight, and the filling weight, and the machine automatically calculates the extrusion rate, conveyor speed, and lift height; see Control Systems.

Manufacturer-Listed Ranges

Each model lists different figures, so you cannot generalize. Taking the publicly listed figures on RHEON's websites as examples:

• In Japan, the KASEIJIN CN700, CN050, CN511, and CN601, as well as the two-row KASEIJIN WN156, all list a ratio adjustable from 1:0 to 0:1.
• The CORNUCOPIA KN500 for the Asia-Pacific market also lists 1:0 to 0:1.
• The U.S. CORNUCOPIA KN551 only states that the "ratio can be adjusted as needed"; refer to the catalog for figures.
• The description of the multi-row Multi Confectioner states that the ratio can be changed freely, or the ratio can be fixed while changing only the weight.

1:0 means dough only (such as mantou or plain dough), and 0:1 means filling only (essentially using it as a dividing machine). These are the mechanical limits; they do not mean every ratio will produce a good-looking product.

What Else Affects Ratio Adjustment?

Besides the feed speed ratio, several other conditions change along with it:

• Nozzle diameter: If the dough passage is too wide, thin dough is hard to extrude evenly; extremely thin dough often requires a matching nozzle.
• Shutter timing and sealing: The thinner the dough, the less of it is available at the seal, so the shutter's closing conditions need to be adjusted accordingly; see Shutter Cutting and Sealing.
• Intermittent filling: RHEON's CN050 comes standard with an "intermittent filling function." According to the manufacturer, it makes the dough thickness more even on thin-skinned products such as inaka manju (田舍饅頭) and on large products such as kasuga manju (春日饅頭). This means the filling flow pauses briefly at the moment the shutter closes, so the seal is made entirely of dough.

Limits of Extremely Thin Dough and Very High Filling Ratios

Common problems when the dough is adjusted very thin include:

• Split seals and exposed filling: There is not enough dough to close up when the shutter gathers it.
• Uneven dough thickness: When the filling is firmer than the dough, it pushes the dough to one side, leaving one side thick and the other thin.
• Bursting during steaming or baking: Dough that is too thin cannot contain the filling as it expands or releases water when heated.

The limits are set mainly by the materials themselves:

• Dough extensibility: Dough with enough gluten and the right water content can be stretched thin without tearing.
• Dough and filling should be similarly firm: If their firmness differs too much, their flow speeds will not match during co-extrusion. This is a matter of rheology; see Rheology and Encrusting.
• Water and oil content of the filling: Too runny and it seeps out; too oily and the dough will not stick together.

So the manufacturer's "1:0 to 0:1" is the range the machine can handle. What ratio each product can actually achieve can only be determined by test runs with your own ingredients.

Ratio Adjustment on Dong-Yih Models

The adjustable ratio range on each Dong-Yih model depends on the model and product, and our website does not list a single standard figure. To find out how thin the dough can be for your product, call us at 06-257-4644 or book a discussion through our Contact page.

FAQ

Q: Can I adjust the dough-to-filling ratio on an encrusting machine myself?
A: Yes. The dough and filling are fed separately, so changing the speed ratio between them changes the ratio. On most newer machines, you set the weights directly on the panel.

Q: What is the maximum filling percentage?
A: It differs by model and product. RHEON's KASEIJIN series lists 1:0 to 0:1, but how thin the dough can actually be depends on the dough's extensibility and the firmness of the filling, so it must be confirmed through test runs.

Q: What should I do if thin dough keeps tearing?
A: First check whether the dough and filling are similarly firm, and check the dough's water content and resting time, then adjust the shutter's sealing conditions. If necessary, adjust the ratio back a bit or switch nozzles.

Q: If I change the ratio, will the weight change too?
A: If you change the feed on only one side, the total weight will change. To keep the weight fixed while changing the ratio, adjust both sides together. On machines with recipe memory, you can enter the dough weight and filling weight directly.