How Shonan Gold Fruit Keeps Getting Better

Kanagawa born and bred and still grown only in the prefecture: the Shonan Gold. This bright yellow, relatively new citrus is a rarity that can only be bought in Kanagawa and selected department stores in Tokyo. What is the key to producing and selling this fruit only in a limited area and maintaining its quality and value?

A sweetness that belies outward appearance

If the Shonan Gold could be summed up in one short sentence it would perhaps be: "A new type of orange that can be enjoyed by all five senses." This is because it possesses a contradictory element not seen in citrus fruit to now and a unique taste that cannot be expressed simply by the word "sweet."

The Shonan Gold is a delight to all five senses from the moment you pick it up. The skin is smooth to the touch and the bright yellow color rejuvenates the eyes. Peeling the skin, you are suddenly enveloped in an invigorating sweet and sour aroma that is completely healing. Biting into a piece, you find the taste belies the imagination: while the lemon-colored skin leads you to expect a strong sour kick, you are amazed by the fresh sweetness. The sour impression the Shonan Gold gives from its appearance may seem like a negative, but the surprise element is one of its main attractions.

One of the most interesting things about this citrus is that its delicious nature cannot be measured by sugar content alone. The Shonan Gold's sugar content averages around 12 to 13 degrees on the Brix scale. This is quite high, but to the taste buds, it seems much higher! The secret seems to lie in the flavor found in the segment walls and the pith. Masafumi Manago from the Kanagawa Agricultural Technology Center was involved in development of the Shonan Gold as a technician and still works in the role as advisor to the cultivar’s production.

"Unlike other citrus fruit, the Shonan Gold's pith is crisp and has a crunchy consistency to it," Manago explains. "The sensation you get from chewing is delicious in itself, which is good, as the pith has nutritional benefits. The aroma you get when you peel it, the sweet and sour flavors on the taste buds, the crunchy texture; these are all things to enjoy with the Shonan Gold. Another thing that only growers maybe can enjoy is that when the fruit ripens on the tree, it develops this rich, pineapple-like flavor. That is not an entirely unexpected thing; fruit evolved many tens of thousands of years ago, there is DNA from various fruit present and citrus does have some pineapple heritage. By the way: if you cut the Shonan Gold open with a kitchen knife, it appears sour to the nose. That is why I always recommend that they are peeled by hand in order to enjoy the aroma."

Aiming for fruit highly valued by consumers

The quest to come up with Kanagawa Prefecture's first home-grown citrus started in earnest back in 1988. After 12 years of development, the new Shonan Gold cultivar was born, the result of a hybrid crossing between the Ogonkan ('Golden Orange') and the Imamura unshiu, a variety of Satsuma orange. Manago recalls the vision that drove the development process:

"What I initially had in mind was something a preschooler could hold in their hands and peel really easily by themselves. There has been a tendency to grow large citrus fruit in recent years, but I wanted to steer clear of doing that. That is why I hoped to make something small that had a good balance between sweet and sour, and that had the nicest fragrance possible — something that was not being done in other prefectures. The aim was not only to add value to the fruit itself, but also provide value to the consumer. I had long thought that the Ongonkan, the Shonan Gold's 'mother', was a delicious variety. However, I was concerned about how difficult it was to peel. So, with solving that problem in mind, we crossed it with around 20 different varieties and eventually settled on the Imamura unshiu.

"To be honest, the quality of the Shonan Gold is only 70% of what I was aiming for. I am still researching how to develop it further to have a lower acid content. Ninety-nine percent of varieties that are created never work out as planned — this isn’t a job you can do unless you love it!" laughs Manago. The passion and research required to deliver something more delicious and pleasing to the consumer knows no end.

A worthwhile challenge

Shonan Gold is grown in two cities and eight towns around Kanagawa Prefecture, including Odawara, Minami-Ashigara, Hakone, and Yugawara. There are currently 220 growers and sellers who belong to the 'SG21' cooperative at which Manago acts as advisor and leads study groups. The cooperative's efforts aim to improve the quality of the fruit across the entire prefecture.

In an effort to undertake quality control, the fruit undergoes a strict sorting regime at the time of shipment. Each fruit is graded as 'superior', 'excellent, or 'good' according to the beauty of their skin and their size; this process is overseen by an official from SG21. In some cases, the official may request that fruit be re-graded.

For growers, the Shonan Gold is not an easy fruit to produce. However, as it is a rare citrus not grown in other prefectures, it can be sold at a higher price; growing them can be worth the challenge. Masayuki Enomoto from the Enomoto Mikan Farm and the Director of SG21 explains the difficulty of cultivating the Shonan Gold:

"The Shonan Gold produces fruit in grape-like clusters under the tree canopy. The thin, smooth skin that characterizes this citrus comes about because the fruit is protected by the tree and not exposed to the direct sunlight; the point at where the fruit grows from is extremely important. While avoidance of direct sunlight may be sought, no gaps in the canopy and insufficient light results in fruit that is not so nice to eat. That is where the grower comes in; they need to carefully select the right branches to prune back in order for just the right amount of sunlight to filter through. The branches grow completely differently on each individual tree so they need to rely on intuition as to where they thin. This step can be one of the most nerve-wracking as it is one that ultimately greatly affects price."

The many uses of the fragrant peel of the Shonan Gold

Shonan Gold is not only sold in its fresh form; with its peel rich in aromatic ingredients, there is demand for it in a pureed form. The various processed products made from the Shonan Gold, such as sweets, jams, dressings, alcoholic beverages, and juice, are very popular as souvenirs from the Shonan area of Kanagawa Prefecture. Yoshiyasu Yasuda is in charge of JA (Japan Agricultural Co-operative) Kanagawa Seisho and talked about the varied Shonan Gold products on sale.

"During the sorting of the Shonan Gold, the fruit destined for processing is classed as 'special product'. The reason why the term, 'for processing' is not used is because even if the fruit is only classed as being for processing purposes only, it still retains a high value, being bought at prices that are around ten times higher than you would get for something like mandarins. Around 40% of all Shonan Gold grown are processed; there are some growers who are engaged in open field cultivation growing the fruit exclusively for processing. To that extent, the Shonan Gold has a different level of value when you talk about so-called 'for processing' fruit."

The land around the city of Odawara where the Shonan Gold is grown is rich in volcanic soil with excellent drainage and abundant nutrients, making it quite suitable for fruit production. Global warming has made it all the more suitable for citrus growing due to rising average temperatures in recent years.

"Citrus production was previously only possible in fairly warm climates," Manago remarks. "Odawara's former average temperature was unsuited to growing citrus, but global warming now makes it possible. The places where citrus can be grown keep moving north, to Gunma, Fukushima, and Aomori. The situation will change little by little in future and I am not sure if we will be able to grow the Shonan Gold as we do now. The important thing is to just maintain focus and keep researching. It's my hope that we will see more enthusiastic researchers from the private sector that from time to time come to the Technical Research Center do this."

Born from the enthusiasm and 'can-do' attitude of Kanagawa, the Shonan Gold will continue to evolve into a more delicious citrus thanks to this relentless inquisitiveness and the technical ability of growers. This spirit of positivity will no doubt be maintained, manifesting itself in the fruit to all that encounter it.