What is the reason the holes in the rice washing bowl are perforated in a mountain shape?
The phrase "mountain-shaped perforations aligned with the flow of water" appears in the product description, and I am asking because I am curious about what role this actually plays when washing and rinsing rice.
It is an arrangement designed so that when the bowl is tilted to pour out water, it aligns with the flow of water so only the water drains smoothly while the rice remains.
Mountain-shaped perforations refer to an arrangement where the holes on the wall of the bowl are grouped and perforated in the shape of an upward-rising ridge. SHIMOMURA's rice washing bowl arranges the punched holes in a mountain shape aligned with the path through which water drains[1].
When the bowl is tilted to the side, the waterway naturally gathers and drains along the ridge shape, helping to prevent rice grains from being swept away by the water and overflowing outside. Unlike colanders with fully perforated bottoms, having holes on the side allows the process of soaking rice in water to be carried out consecutively in a single bowl.
It measures 19cm in diameter and 8.5cm in height[2]. It is a suitable volume for filling with water and lightly rinsing rice when preparing meals in a regular household. The main body is made of 18-8 stainless steel, making it resistant to rust and discoloration[3], and it can be placed in a dishwasher for cleaning after use[4].

The maximum capacity of rice suitable to wash at one time has not yet been confirmed in official materials.
Product measurements
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[시모무라] 스텐 쌀 씻는 볼 (19cm)
Measurements
| Part | Value |
|---|---|
| 무게 | 225g |
| 용량 | 360ml |
Other stated figures
| Part | Value |
|---|---|
| 사이즈로 ◦ | 1~2cm |
| 쌀 ◦ | 2cm |
For rows marked with ◦, flat measurement or circumference could not be confirmed in official sources, so hmmm determined them using figures from the same item.
![[시모무라] 스텐 쌀 씻는 볼 (19cm)](https://img.hmmm.pub/brands/shimomura/products/a64aac21-35e7-4f85-86f2-816ab9997573/1.jpg)