Yukimuro Aging

Traditional Japanese storage and aging method using snow Leveraging the power of nature

Mellow, rich, and melt-in-your-mouth taste

◆ What is Yukimuro (snow storage)?

A natural refrigerator that brings out the best of food

From olden days in Niigata, a Yukimuro, a hole dug in the ground, filled with snow and then covered with straw, has been used for the refrigeration of fresh food in the winter. This wisdom in the snow country has been handed down for generations.

Today, it is possible to construct a Yukimuro by storing a large amount of snow in a building, and this enables the preservation of a large volume of food for extended periods. A Yukimuro maintains a stable "low-temperature, high humidity" condition, with the temperature of between 1 to 2 °C and approximately 90% humidity. This allows meat to age, bringing out delicious sweetness and mellowness. Meat aged in a Yukimuro becomes tender and moist as oxygen breaks down fibers. Proteins are also broken down and the content of free amino acid in meat increases, which gives it a mellow, rich, and melt-in-your-mouth taste.

◆ Slow aging of beef in Yukimuro—Yukimuro Aging (snow aging)

Created the world's first aged meat using the Yukimuro storage method

Uoshoku has continued to conduct a study of beef aging including storage technology and period through years of trial and error, making use of the traditional Yukimuro preservation method of the snow country. The result is snow Aging Beef, which is snow aged at a stable temperature and humidity conditions in a snow storage. Unlike electric refrigeration with a thermostat, snow aging storage facilities are frost-free and allow aging at a constant temperature and humidity.

  • Mountainous area in Niigata

  • Snow Aging Beef・Wagyu

What is Yukimuro (snow storage)?

A natural refrigerator cooled with snow. A method born in the snow country (Niigata) in Japan to preserve food in a snow-cooled storehouse.

Structure of Yukimuro

Yukimuro…Able to cool the refrigerator storage area throughout the year with snow accumulated during the winter.

About Aging

  • Temperature: 1‒2 °C
    Average temperature: 1.2 °C
  • Humidity: 90‒95%
  • Wet Aging

Effect of Yukimuro Aging

  • Oxygen breaks down fibers,making the meat tender
  • Proteins are broken down,increasing the content of free amino acid to enhance flavor
  • Results in a mellow, rich, and melt-in-your-mouth taste

When snow aging Japanese Beef Rib

Sensory test on Snow aging beef

Power of Yukimuro(Snow Storage)

◆ General Refrigerators

  • Vibration is generated by general refrigerators.
  • Due to the active and inactive operation of machines, temperature is unstable,

◆ Yukimuro (Snow Storage)

  • A traditional storage method using the features of snow exists in Niigata from olden days.
  • The temperature of the snow storage is between 1 to 2 °C and the humidity is maintained at 90% or above throughout the year, allowing meat to age in a stable environment.
  • Not affected by changing temperature, vibration, light, and dryness, slow aging takes place without putting stress on food.
  • Gentle aging with ecologically natural power (clean energy).

Site of Yukimuro Aging

Snow Aging Beef・Wagyu

Cuisine-Kingdom 100 Items

Selected as one of the Cuisine-kingdom 100 items!
Snow Aging Niigata Wagyu

Published on the Michelin Guide website→

Japanese Snow Aging Beef

Yukimuro Aging

Japanese Wagyu beef aged in a Yukimuro produces the highest-quality Japanese Wagyu beef.

High-quality Wagyu beef is aged in Yukimuro in Uonuma, for a tender and tastier flavor.

Wagyu Grade A3,A4,and A5

  • Sirloin
    Approximately 10‒13 kg each

  • Top Round
    Approximately 9‒10 kg each

  • Rump
    Approximately 8‒10 kg each

Japanese Snow Aging Beef

Yukimuro Aging

Pursuing delicious red meat with Yukimuro

Select Japanese crossbreeds are aged in Yukimuro in Uonuma, Niigata, bringing out the wonderful flavor of tender red meat.

  • Sirloin of Wagyu Cross
    Approximately 10‒13 kg each

  • Rump of Wagyu Cross
    Approximately 8‒9 kg each

  • Top Round of Wagyu Cross
    Approximately 9‒10 kg each