Mochi Maker

Overview

A mochi maker is a specialized rice-pounding machine that cooks glutinous rice by steam and then automatically pounds and kneads it into smooth, elastic mochi dough. This is a countertop model with a sealed Housing & Enclosure that contains a Steaming Chamber, where a Rice Basket of rice is steamed above a Water Reservoir. Once the rice is translucent and sticky, the Induction Motor engages to drive the Pounding Paddle and Kneading Scraper through a kneading cycle. The Control Board sequences heat and motor phases via a Timer Dial, while Door Interlock Switch and Pressure Relief Valve ensure safe operation.

The Teflon-Coated Bowl is coated with PTFE to prevent the starch from sticking. Its Bowl Mounting Ring centers it under the paddle, and the Stroke Guide Rail keeps the paddle's motion purely vertical as it impacts and folds the rice. At cycle end, a Release Spring retracts the paddle fully, and a Lift Latch holds it high so the operator can swing open the Door Hinge and remove the finished mochi.

How it works

Steam is generated by an immersion Heating Element (1200 W) that heats water in the Water Reservoir. A Thermostat Switch cuts the heater at 100 °C, maintaining 100–105 °C steam. The operator fills the Rice Basket with 2 kg of glutinous rice and water, closes the door to seal the Sealing Gasket, and sets the Timer Dial to 45 minutes. During this phase, steam condenses on the rice grains, hydrating them until they fuse into a cohesive mass.

When the timer sounds, the Mode Selector Switch shifts the Control Board to the knead phase. The Induction Motor, an AC induction motor, spins at 1000 rpm. A Gear Reducer reduces this to 60 rpm on the Drive Shaft. An eccentric crank on the shaft converts this rotation into a reciprocating motion, pulling the Pounding Paddle up and down 60 times per minute through an 8 cm stroke. The serrated edge of the paddle cuts the rice mass, while the Kneading Scraper (mounted diametrically opposite) continuously folds material from the rim toward the center.

Pressure rises during the cook phase. A Pressure Relief Valve valve opens if internal pressure exceeds 150 kPa, venting excess steam through the mochi-maker-steam-vent-cap. After 15 minutes of kneading, the timer sounds again, the Control Board de-energizes the Induction Motor, and a solenoid Release Trigger springs the Release Spring, shooting the paddle upward and latching it at full height. The operator opens the door (which mechanically resets the Door Interlock Switch interlock) and scrapes the finished mochi from the Teflon-Coated Bowl with a wet spatula.

All electrical circuits run through a Power Cord plugged into mains. A Thermal Fuse at 10 A provides overcurrent cutoff. The Control Board is a simple PCB with Relays sequencing the Heating Element, the Induction Motor, and the Release Trigger solenoid based on time and the Door Interlock Switch state.