The Manufacturing Process of Sandwich Rice Crackers

The Manufacturing Process of Sandwich Rice Crackers

Sandwich rice crackers are a popular and beloved snack worldwide, known for their crisp texture, savory or sweet flavors, and the delightful contrast between the airy rice crackers and the creamy filling. The production of these snacks is a fascinating blend of traditional baking principles and modern food engineering. The process can be broken down into three main stages: 1) Production of the Rice Crackers, 2) Preparation of the Filling, and 3) Assembly and Packaging.

Stage 1: Production of the Rice Crackers (Senbei)

The foundation of the snack is the crisp rice cracker.

1. Ingredient Mixing:
The primary ingredient is rice flour, often from Japonica rice varieties for their specific starch properties. This flour is mixed with water, sugar, salt, and sometimes starch or tapioca flour to improve texture. The mixture is kneaded into a smooth, consistent dough.

2. Sheeting and Shaping:
The dough is then passed through a series of rollers to form a thin, continuous sheet of uniform thickness. The desired shape—round, rectangular, or peanut-shaped—is stamped out from this sheet using rotary cutters. The scrap dough is recycled back into the mixing step to minimize waste.

3. Baking or Grilling:
The shaped dough pieces are then cooked. There are two primary methods:

• Baking: The most common industrial method. The pieces pass through a long, multi-zone oven. The initial zones use high heat to rapidly expand the water into steam, creating the characteristic porous and airy structure. Later zones use lower heat to dry and crisp the crackers without burning them.
• Grilling: A more traditional method that imparts a different flavor. The crackers are grilled on wire meshes, which can give them slight char marks and a smokier note.

4. Seasoning (First Application):
After baking, the base crackers are often seasoned on their surface. They pass under a seasoning sprayer or through a drum where powdered seasonings like soy sauce, sugar, or nutritional yeast are applied. A light mist of oil may be used to help the seasoning adhere.

5. Drying and Cooling:
The baked and seasoned crackers are very moist and pliable straight from the oven. They are conveyed through a cooling tunnel where ambient or forced air cools them down and removes residual moisture, finalizing their crisp texture.

Stage 2: Preparation of the Filling

The filling provides the creamy “sandwich” center and is crucial for flavor.

1. Ingredient Blending:
The base of the filling is typically a combination of sugar, vegetable oils, and starches. Other ingredients are added based on the target flavor profile:

• Peanut Butter: For a classic flavor.
• Chocolate: Cocoa powder or melted chocolate.
• Cheese: Cheese powder.
• Sweeteners: Malt syrup, honey, or corn syrup.
  All ingredients are blended in large mixers into a smooth, homogenous paste. The consistency is critical—it must be pliable enough to spread but firm enough to hold its shape.

2. Conching and Aeration:
For certain fillings, especially chocolate-based ones, the mixture may undergo a process called “conching” in a special mixer. This process continuously kneads the mixture under heat, developing a smoother texture and mellower flavor. Often, the filling is slightly aerated to make it lighter and easier to spread.

3. Tempering and Storage:
The filling is then transferred to holding tanks or hoppers, where its temperature is carefully maintained to ensure it remains at the ideal viscosity for the application process.

Stage 3: Assembly and Packaging

This final stage brings the components together.

1. Filling Application:
The filling is applied to the flat side of one rice cracker. This is done with high precision by a filling machine, which deposits a pre-measured amount of filling via a nozzle. A second cracker is then precisely placed on top to form the sandwich. The pressure is carefully controlled to secure the bond without breaking the delicate crackers.

2. Final Drying/Setting:
The assembled sandwiches may pass through a short, cool-air tunnel. This step sets the filling, ensuring it doesn’t squeeze out when the package is handled later.

3. Quality Check:
Optical scanners and automated systems check the sandwiches for defects—such as broken crackers, misalignment, or insufficient filling. Any substandard products are automatically rejected from the production line.

4. Packaging:
The合格品 (acceptable products) are immediately fed into packaging machines. They are counted and placed into foil-lined bags or pouches. These bags are flushed with nitrogen gas before sealing. This process, called nitrogen flushing, removes oxygen that would cause the crackers to become stale and the filling to become rancid. This is the key to maintaining freshness and a long shelf life.

5. Cartoning and Distribution:
The individual bags are then packed into cardboard boxes and palletized for distribution to warehouses and retail stores worldwide.

In conclusion, the creation of a sandwich rice cracker is a complex, automated, and carefully controlled process. Each step, from baking the perfect airy cracker to formulating a stable filling and ensuring airtight packaging, is essential to delivering the consistent quality, texture, and flavor that consumers enjoy.