Japanese Rinoka Lemons
Estimated Inventory, lb : 0
Description/Taste
Rinoka lemons are a medium to large variety, averaging 90 to 200 grams in weight, and have an oval, spindle, tapered shape with slightly pointed or blunt ends. Each lemon typically has one rounded end, and the skin ripens from green to golden yellow hues. It is important to note that Rinoka lemons can be used in their green or yellow stages. Some fruits may also showcase a mottled hue, transitioning between being slightly young to ripe. The skin is characteristically thin and is taut, firm, and textured, covered in sunken oil glands, giving the surface a pitted feel. The skin can also be peeled by hand, revealing pale yellow flesh divided into 9 to 11 segments by thin, barely noticeable membranes. The flesh is comprised of large juice vesicles, creating a soft, tender, aqueous, and succulent consistency. The flesh also encases a few seeds or is found seedless, depending on cultivation conditions. Rinoka lemons emit a light, refreshing fragrance with floral nuances. The lemons are edible raw and have low acidity, mixed with high sugar, bearing a mellow, sweet, and sour taste.
Seasons/Availability
Rinoka lemons are available in Japan from late summer through mid-spring. Green Rinoka lemons appear in markets between September and November, and Yellow Rinoka lemons are found from November through March.
Current Facts
Rinoka lemons, botanically a part of the Citrus genus, are a Japanese variety belonging to the Rutaceae family. The cultivar was developed in the late 20th century and was commercially released as an improved lemon with increased disease resistance, especially to canker, a problematic citrus disease. Rinoka lemons are not widespread and are primarily grown as a specialty cultivar in Japan. The variety produces high yields and ripens about one month earlier than other commercial lemons like Lisbon and Meyer. Rinoka lemons also have thin, edible skin and ample amounts of flesh and juice, making them ideal for a wide array of culinary preparations and beverages. In Japan, Rinoka lemons are also known under the original variety name of Okitsu No. 66 and are a seasonal citrus promoted for its entirely edible nature, low acidity, and refreshing taste.
Nutritional Value
Rinoka lemons have not been extensively studied for their nutritional properties. Lemons, in general, are sources of vitamins B, C, and E to strengthen the immune system, guard the cells against free radical damage, and contribute to energy production in the body. Lemons also provide fiber to aid digestion and minerals like calcium, phosphorus, potassium, magnesium, iron, and copper. These minerals support bone and teeth health, balance fluid levels within the body, promote oxygen transport through the body, and assist in controlling daily nerve functions.
Applications
Rinoka lemons have a refreshing, sweet, and sour taste suited for raw and cooked preparations. The entire lemon is edible, including the skin. Most commercial lemons have a bitter-tasting rind, but Rinoka lemons are known for lacking this bitter flavor, making them a favored cultivar for fresh dishes. Rinoka lemons can be thinly sliced and served over sushi, chopped for other raw dishes, or used as a garnish over cooked fish. The lemons are also incorporated into salads or layered into sandwiches for a bright addition. In Japan, Rinoka lemons are juiced into yogurt sauces, glazes, ponzu, or lemon-onion soy sauces. They are also added to miso, koji, and dashi. Green Rinoka lemons are valued for flavoring drinks like sparkling beverages, lemonade, and tea. Wedges of citrus can also be sliced and stirred into drinks and water. In addition to raw uses, Rinoka lemons are simmered into jams, jellies, and marmalades, which are spread on crackers and desserts. They also flavor baked goods like shortbread, cakes, and tarts. Beyond sweet dishes, Rinoka lemons are squeezed as a pop of flavor over grilled fish, fried pork, and chicken in Japan. The lemons are also sprinkled over vegetable dishes like roasted potatoes. One unusual use of Rinoka lemons is adding them to chicken ramen. Some restaurants in Japan serve a portion of lemon with the soup to juice and grate fresh as they eat the dish. Rinoka lemons pair well with herbs like shiso, mitsuba, and wasabi, aromatics like ginger, garlic, and green onion, and flavorings like sake, mirin, and bonito flakes. Whole, unwashed Rinoka lemons will keep for a few days at room temperature and for a few weeks when stored in the refrigerator’s crisper drawer.
Ethnic/Cultural Info
The name Rinoka roughly translates to “the scent of treasure.” This name was given to the variety for its refreshing scent and mellow flavor, a unique combination for commercial lemons. In the city of Shiroishi in the Miyagi Prefecture, a contest was held in January 2025 to give Rinoka a local nickname. Rinoka lemons have been grown near Shiroishi since 2017, and the city plans to position the lemons as a specialty product of the region. The nickname contest ran for the month of January, and the city received 948 submissions. It is said that two submissions will be selected as winners, and the winning entries will be given agricultural-centric gifts worth 10,000 yen. The winning entries have yet to be announced as the city is in the process of trademarking the names, but once protected, the names will be revealed and used for Rinoka lemons specifically grown in the Shiroishi region.
Geography/History
Rinoka lemons are native to Japan and were developed through the Ministry of Agriculture, Forestry and Fisheries' Fruit Tree Experiment Station, now known as the National Agriculture and Food Research Organization's Fruit Tree Research Institute's Citrus Research Okitsu Base. The variety was created from a cross in 1991 between Lisbon lemons, the seed parent, and Hyuganatsu citrus, the pollen parent. The goal of the cross was to create an improved cultivar that had increased resistance to canker disease while also displaying other favorable characteristics like yields, taste, and appearance. The chosen seedling from this cross was initially called Okitsu No. 66 and was submitted as a new variety in 2013. Later in 2015, the cultivar was registered as an official variety by the National Agriculture Food Research Organization under the name Rinoka lemons. Today, Rinoka lemons are localized to Japan and are commercially grown as a specialty citrus. The variety is cultivated in greenhouses and outdoors and is seasonally found in fresh markets and select retailers.
