Ready for Hot Summer: Making Umeboshi (Pickled Plums)

That summer sunshine, the sweat pouring out and the hazy head, and the swirling dust.

This is a memory from my elementary school days, on the day of the school sports festival. Every summer’s end, the school would organize a sports festival on the sandy playground. It was a school-wide competition in which students from first through sixth grade were divided into red and white teams by class and competed for points in various sports. There were activities such as tug-of-war, three-legged race, and group gymnastics. I wasn't comfortable being outdoors for extended periods, feeling somewhat overwhelmed by the unfamiliar heat.

After spending the entire day under the scorching sun, I came back home without having a chance to cool down from all the excitement. It was then that an unexpected craving hit me—a longing for my grandmother’s umeboshi (pickled plums), something I had never thought of before.

Benefits of Umeboshi

Umeboshi are rich in citric acid and malic acid, amino acids which are thought to help break down lactic acid that accumulates in the muscles. Because lactic acid buildup is associated with muscle fatigue and soreness, pickled plums have long been considered a very effective way to help the body recover from fatigue. Umeboshi also contain salt, making them suitable for replenishing electrolytes after exercise.

Umeboshi were a regular part of the dinner table at home. Although I knew they were good for my body, all I could taste was their sourness, and at one point, I thought I might not like them very much after all. But the umeboshi I had on this sports day were different. How delicious they were!

And I could feel firsthand how beneficial they were to my body and how they helped relieve my fatigue. It was truly a great opportunity to enjoy umeboshi.

Umeboshi are enjoyed not only during exercise or in summer. They have long been valued in Japan as part of the everyday diet and are known for their distinctive sourness, which comes primarily from citric acid.

So, if umeboshi are the embodiment of health, why not make them myself?

Day 1: Let’s Make Umeboshi!

I will make two types of umeboshi: authentic salted umeboshi and slightly sweet umeboshi with honey.

Honey umeboshi have a unique flavor where the acidity of umeboshi and the sweetness of honey blend perfectly. The aroma of honey enhances the fragrance of umeboshi, making it even more delightful. Even those who are not particularly fond of regular umeboshi might find this version more enjoyable.

*When making plum syrup, we used unripe plums, but this time for umeboshi, we used ripe plums with soft flesh and a delightful fragrance.

Ingredients

Umeboshi

• 70.5 oz (2 kg) ume plums
• 12.7 oz (360 g) salt (18% of the weight of the plums)

Honey Umeboshi

• 70.5 oz (2 kg) ume plums
• 10.6 oz (300 g) salt (15% of the weight of the plums)
• 2.8 oz (80 g) honey (4% of the weight of the plums)
• 4.2 oz (120 g) granulated sugar (6% of the weight of the plums)

For the honey umeboshi, first mix the salt and honey together.

1. Remove the stems, as well as any plums that are too soft or spoiled, as they may cause the others to rot faster.

2. Rinse the plums with water.

3. Gently wipe the plums to dry them slightly.

4. Allow the plums to dry for a short period.

5. Neatly place the plums into a sterilized container, one layer at a time. Repeat the process of sprinkling salt on the plums, ensuring that the salt is evenly distributed over all the plums. The salt has a sterilizing effect and helps prevent the plums from spoiling.

(For honey plums, sprinkle granulated sugar on top.)

6. Fill a bag with water and place it in the jar (to be used as a weight). Store the jar in a place away from direct sunlight.

Day 2: Infusing Color and Flavor with Red Perilla

What image comes to mind when you think of umeboshi? You might picture them as red. But did you know that their red color actually comes from red perilla, not just the umeboshi itself?

Red perilla is added for aesthetic purposes, creating a visually appealing contrast with white rice. The red color is produced through a chemical reaction between components in the red perilla and the citric acid in umeboshi.

Besides adding color, red perilla provides nutritional benefits and antimicrobial properties to umeboshi. Perilla is an herb native to China and has traditionally been used medicinally to treat food poisoning.

The addition of red perilla is timed to coincide with the maturation of the plum vinegar (umeboshi vinegar), typically three to seven days after starting the umeboshi-making process.

Now, let’s prepare the red perilla.

Ingredients

• Red perilla leavesPrepare a minimum of 10% and a maximum of 20% of the weight of the plums to achieve a strong color and flavor.
• SaltUse approximately 17-18% of the weight of the red perilla leaves.

1. Remove the thick green stems and discard them.

2. Wash the red perilla leaves to remove any dirt, then drain them well in a colander to remove excess water.

3. Place the red perilla leaves in a large bowl and add half of the salt. Knead the leaves well to release any bitterness.

4. Squeeze the liquid from the red perilla leaves and discard it. Return the squeezed red perilla leaves to the bowl and sprinkle the remaining salt over them.

5. Knead the leaves again, and you will notice more liquid being released. Squeeze out the liquid once more and discard it. This helps remove as much bitterness and astringency as possible.

6. Add about 6.7 fl oz (200 ml) of the umeboshi vinegar collected from the umeboshi container to the squeezed red perilla leaves and mix well. The vinegar will quickly turn red, indicating that a chemical reaction has started.

7. Spread the red perilla leaves over the umeboshi and pour in the red-colored vinegar. Finally, use chopsticks to gently separate and mix the red perilla leaves, allowing them to blend well with the vinegar and distribute their color throughout the container.

8. Place a weight on top of the umeboshi so that they are fully submerged in the vinegar. Leave them until the rainy season has passed and the plums are fully pickled.

Day 3: Drying plums

1. Take the umeboshi out of the container and place them on a drying tray to facilitate the drying process.

2. Arrange the plums one by one and position them in a sunny spot.

3. In the evening, move the sieve indoors.

4. After a few more days, flip the plums and continue drying them for several more days.

5. Once the plums’ skins become soft after the sun-drying process, umeboshi are complete.

Making umeboshi with family, friends, or others can be a fun activity with lively conversations. The joy continues not only during the preparation but also as you wait for them to be ready to eat. Observing the gradual changes in the pickled plums inside the jar made me look forward to going to work every day!

If you would like to know our impressions after tasting various plum delights like plum syrup, plum wine, and umeboshi, read our journal, Taste the Essence of Summer: Making Umeshu (Plum Wine) and Plum Syrup.