Zojirushi Commercial Thermal Rice Warmer, 4L (22-Cup) - RDS-400

The Zojirushi RDS-400 is a commercial non-electric thermal rice warmer designed to hold cooked rice without powered heating. Its 4-liter capacity accommodates approximately 22 rice-cup measures, making it a compact holding solution for sushi bars, Japanese restaurants, catering operations, and other foodservice environments where cooked rice needs to remain warm away from an electrical outlet.

Unlike an electric rice warmer, the RDS-400 relies on thermal insulation rather than continuous heat. Zojirushi specifically designs the unit for acidic ingredients such as vinegar, making it particularly well suited to seasoned sushi rice. The stackable body conserves space during storage and transport, while a reusable condensation-collecting sponge in the lid helps manage moisture during holding.

The RDS-400 offers 4 liters of non-electric holding space for prepared rice. Insulation retains existing heat without a power cord or active heater, making the holder useful where an outlet is inconvenient. It is not a rice cooker, and its volume should not be converted into a guaranteed number of servings.

The stainless steel interior is suited to acidic preparations such as vinegared sushi rice. A replaceable condensation sponge sits beneath the lid, and the body is designed to stack. Preheat and care for the holder using the model’s instructions; published six-hour water-test results are laboratory retention measurements, not a safe rice-service duration or guaranteed holding temperature.