1. How People Got Ice in Summer Before Refrigerators
Before ice-making companies started in 1883, getting ice in summer was hard. The only ways were importing it or saving it from winter in special storage called himuro (ice houses) [1]. Imported ice from Boston, USA, was very expensive [2]. Nakagawa Kahei wanted to make ice in Japan to make it cheaper [2]. This led to new ways of finding ice in Japan.
2. How Nakagawa Kahei Used the Goryokaku Moat in Hakodate to Make Natural Ice
Nakagawa Kahei failed to make ice at the foot of Mt. Fuji. He then looked at Goryokaku in Hakodate in 1869. In 1870, he got permission to use the moat. In 1871, he cut about 670 tons of ice and it is said he commercialized it as "Hakodate Ice" [2]. Note that dates in records can vary by 1 or 2 years, so treat them as approximate.
670 tons equals 670,000 kg. If you divide this by the 135 kg ice cylinders mentioned later, that is about 4,960 cylinders. This shows how much ice nature made in winter. The ice was shipped from busy Hakodate to Yokohama. It is introduced that some was sold by an ice seller in Ginza, Tokyo [3]. So, summer ice in Tokyo came from a northern moat in winter.
But natural ice needs a cold winter. How did other places make ice?
3. How Natural Ice Is Grown in Winter Ponds and Kept With Sawdust
In Nikko, natural ice is made in ponds from January to February. It takes about 2 weeks to freeze. When it is about 15 cm thick, it is cut. The ice is put in himuro and covered with cypress sawdust to keep it cold [4]. In the early Showa era, there were nearly 100 ice houses in Japan. By 2024, only 5 remained, and 3 are in Nikko [4].
The Kanaya Hotel shows how natural ice depends on cold weather. In 1918, they cut ice from a frozen pond on Mt. Ogura and used it for food storage. But around 1929, the ice became too thin to harvest, so they started buying it from ice shops [5]. Natural ice is risky because it depends on how cold the winter is.
So, factories became the main source of ice.
4. Why Factory-Made Ice Takes 48 Hours to Freeze in a 135 kg Block
Factory ice is called "can ice." Stainless steel cans are sunk into a tank of brine (cooling liquid with calcium chloride). They are frozen at about −10°C. A 135 kg can takes more than 48 hours. The ice grows at a speed of 2 to 3 mm per hour [6]. Another company says pure ice takes 48 hours to become clear, and raw ice before processing is 135 kg [7].
If ice grows 2 to 3 mm per hour for 48 hours, it becomes 96 to 144 mm thick. This is about 10 to 14 cm. The source does not say which direction the ice grows in the can, so this is just a guide for speed. The 300-pound (135 kg, 36 kanme) can size is still used. Japan’s ice technology came from the UK in the Meiji era [6]. 300 pounds is about 136 kg, so 135 kg is a rounded number. −10°C is one factory’s example, not a rule for all.
After checking and cleaning, the ice is cut into slabs (1.7 kg or 3.6 kg) or crushed ice [7]. Ice sellers delivered this factory ice.
5. How Ice Carts and Ice Refrigerators Kept Food Cold for One Day
An ice refrigerator was a wooden box lined with tin. Ice went on top, food below. The cold air cooled the food [8]. Ice bought from sellers in the morning could keep the inside cold for one day [8]. You can think of it like charging a battery, but the ice melts and disappears.
Ice sellers pushed carts to deliver ice to homes every morning. They cut ice with a saw and lifted it with tongs [9]. They likely cut different amounts for each house, but the source does not confirm this. An example ice refrigerator is 72 cm high, 44 cm wide, and 40 cm deep. Japanese-made ones started selling in the late Meiji era. They were used until electric fridges spread around 1955. They were expensive, so not every family had one [9].
Ice sellers delivered the ice for these boxes. Electric refrigerators changed this life.
6. What Happened to Ice Sellers When Electric Refrigerators Arrived
The first Japanese home electric refrigerator was the Toshiba SS-1200, finished in 1930. It held 125 L, weighed 157 kg, and cost 720 yen. A bank clerk’s first salary was about 70 yen [10]. 720 divided by 70 is about 10, so it cost about 10 months of salary. We use Toshiba’s official date here.
Adoption was slow at first. In 1957, only 2.8% of homes had electric fridges. By 1970, it was 89.1% [11]. This is about 32 times more in just 13 years.
Licensed ice-selling facilities numbered 7,938 in 1970. As home fridges and automatic ice makers in restaurants spread, this number dropped to 1,587 in fiscal year 2023 [12]. 1,587 divided by 7,938 is about 0.2, or one-fifth. This is not the exact number of ice sellers, but licensed facilities. The Ministry of Health, Labour and Welfare suggests selling high-quality pure ice to people who want it, or making ice sculptures for events [12]. Daily delivery ended, but ice remains in shaved ice and sculptures.
7. An Experiment: Measuring How Long Ice Takes to Freeze at Home
Put water in an ice tray and put it in your freezer. Check it every hour. Write down how many hours it takes to freeze completely. The 48-hour factory time is for 135 kg cans in −10°C brine. Home ice differs in size and temperature, so the time will be different.
You can also check if a local history museum has an ice refrigerator on display. Museums in Nishi Ward or Morioka City may show ice refrigerators in displays about old life. Ask your family about their memories of ice or refrigerators from when they were children. This adds human stories to the numbers in this notebook.