The Star of Umeshu: Understanding the Japanese Ume Plum

Behind every delicious, amber-hued glass of Umeshu lies its most crucial ingredient: the Japanese Ume plum (梅 - ume). These unique fruits are not just any plum; their specific characteristics are what make Umeshu the beloved liqueur it is. Understanding the Ume is key to appreciating the art and tradition of Umeshu making.

What Exactly is Ume?

Botanically known as Prunus mume, the Ume is often referred to in English as a "Japanese plum" or sometimes even a "Japanese apricot." While related to both, it holds a distinct place. Unlike the sweet, juicy plums or apricots you might eat fresh, Ume plums, especially when used for Umeshu, are prized for different qualities. They are an integral part of Japanese cuisine, also famously used to make umeboshi (pickled plums).

The Perfect Stage: Unripe and Green

For Umeshu production, Ume are harvested when they are still unripe, firm, and vibrantly green. This typically occurs from late May to early July, coinciding with Japan's rainy season (tsuyu - 梅雨, literally "plum rain," highlighting the fruit's seasonal importance).

Why unripe?

• Tartness and Acidity: Unripe Ume possess a high level of citric acid and a pronounced tartness. This acidity is crucial for balancing the sweetness of the sugar used in Umeshu and for extracting the fruit's full flavor profile.

• Firmness: Green Ume are firm, which helps them hold their shape during the long steeping process and prevents them from turning mushy too quickly.

• Aroma: Even when unripe, Ume have a distinct, refreshing, and slightly floral aroma that beautifully infuses into the alcohol.

Key Characteristics That Make Ume Ideal for Liqueur:

• Intense Flavor: Despite their raw tartness, Ume plums pack a powerful, complex fruity flavor that mellows and deepens wonderfully during steeping.

• Subtle Almond Note: The pit (kernel) of the Ume contains amygdalin, which, in small, safe amounts during the steeping process, can contribute a delicate, marzipan-like or almondy nuance to the final Umeshu. This is a signature characteristic that many connoisseurs appreciate. (Care is taken in traditional preparation to ensure safety).

• Good Extraction Properties: Their composition allows their juices, color, and aromatic compounds to effectively infuse into the base alcohol and sugar mixture over time.

Popular Varieties for Umeshu:

While various local Ume can be used, some varieties are particularly favored for Umeshu making due to their size, fleshiness, and flavor profile. One of the most renowned is Nanko-ume (南高梅), primarily cultivated in Wakayama Prefecture. Nanko-ume are prized for their large size, soft, thick flesh, small pit, and wonderfully fruity aroma, making them ideal for producing high-quality Umeshu.

Preparing Ume for their Umeshu Journey:

Before being steeped, the Ume plums are meticulously prepared:

1. Washing: They are gently washed to remove any dirt.

2. Drying: Thoroughly dried to prevent spoilage.

3. Removing the Calyx (Heso): The small, dark, inedible stem end or calyx (navel, or heso in Japanese) is carefully removed using a bamboo skewer or toothpick. This step is important as leaving it on can impart a bitter or astringent taste to the Umeshu.

Some recipes also call for pricking the plums with a fork or needle to help release their juices more readily, though this is not universally practiced.

The Transformation During Steeping:

Once layered with rock sugar and submerged in alcohol, the Ume plums begin their slow transformation. Osmosis draws out the plum juice, which then mingles with the dissolving sugar and alcohol. The plums will gradually shrink and wrinkle as they release their essence, imparting their golden color, tangy flavor, and delicate fragrance to the liquid.

The Bonus: Edible Ume in Your Umeshu:

After the Umeshu has matured, the steeped plums themselves become a delightful, boozy treat. They are perfectly edible, having absorbed the sweetness of the sugar and the kick of the alcohol, while retaining a pleasant tartness and a uniquely tender-chewy texture. Many people enjoy eating them as a snack or using them as a garnish.

The humble green Ume, too tart to be enjoyed raw by most, is truly the soul of Umeshu. Its transformation through a simple process of steeping results in one of Japan's most iconic and versatile liqueurs.