Discovering Dekopon: Japan’s Delicious Citrus Fruit

What is Dekopon? Ι  History and names  Ι   What does Dekopon taste like?  Ι   Where is Dekopon grown?  Ι   How is Dekopon used?   Ι  Recipes

What is Dekopon?

What is dekopon?

Dekopon (Citrus reticulata ‘Shiranui’) is a seedless mandarin variety, that is a cross between the Ponkan or Chinese honey orange (Citrus poonensis) and the Kiyomi (Citrus unshiu × sinensis).

Kiyomi and ponkan

Dekopon produces large fruit ranging from 8 – 10 cm in diameter, with a round shape and a distinct bulge on the top that is sometimes referred to as a top knot. The bumpy skin is bright orange and approximately 4.8 mm thick, and beneath is a thin layer of pith, which protects the delicate hesperidium (sectioned) pith.

Dekopon is a portmanteau made up of deko which means bump or uneven and pon, in reference to the ponkan mandarin. Initially, this unusually shaped fruit didn’t attract much interest, however, the sweet flavour of this fruit eventually won the public over. There is a growing interest in Dekopon outside Japan.

Dekopon

History and names

Dekopon is a species of citrus native to Japan where it is known for its sweet, almost seedless fresh and unique conical shape. The large fruit has a bright orange colour that is harvested in winter. Dekopon is considered to be one of the best-tasting citrus fruits and is highly prized in Japan and it is given as a gift or used in high-end culinary dishes.

Dekopon was developed in 1972 by the Agricultural Research Organisation, Nagasaki Prefecture. The goal was to produce an easy-to-peel, sweet citrus with no seeds. Initially, the fruit was not registered due to the unattractive bump on the top and the sour taste of the fruit immediately after harvest. Seedlings were transported to Shiranui-cho, Uto-gun, Kumamoto Prefecture, where they grew in a test garden. Shingo Nagame, director of the experimental garden ate a fruit that had been harvested and left out and found the fruit had developed a sweet taste.

The generic name for Dekopon is ‘Shiranuhi’, is named after the former town Shiranuhi (不知火町), which was located in Uto District, Kumamoto Prefecture and is now Uki City.

Dekopon is a trademarked name owned by the Kumamoto Fruit Agricultural Cooperative Association.  In Hiroshima, the Dekopon is marketed as Kiyopon, and unlike Dekopon, this name doesn’t appear to be trademarked.

In South Korea, the Dekopon is known as ‘hallabong’, named after Hallasan Mountain on the island of Jeju, where the fruit is primarily grown.

What does Dekopon taste like?

Dekopon is one of the most popular fruits in Japan and worldwide interest is rapidly increasing. The flavour of Dekopon is described as a cross between an orange and a mandarin. A thin membrane covers the segments, which are firm, juicy and sweet with a slightly acidic taste.

Brix refers to the sugar content in citrus fruits. While all Dekopon are ‘Shiranuhi’, not all Shiranuhi are Dekopon. For the fruit to be called Dekopon, it must reach a minimum of 13 Brix but can be as high as 18 with 1.0% citric acid levels. This is in contrast to oranges with an average Brix level of 10 and 6 for limes.

Where is Dekopon grown?

In Japan, Dekopon is usually grown in a large greenhouse to ensure a constant temperature. Ripe fruit can weigh between 250 grams and are harvested during the winter months.

The main production areas are Kumamoto, Ehime, and Wakayama Prefectures.

United States

Outside Japan, Dekopon is sold under the trademarked name Sumo Citrus as a licensed and controlled brand. Citrus farmer Brad Stark Jr. imported a budwood branch into the United States in 1998. The importation of citrus into the United States is mostly prohibited to protect farmers as well as prevent introducing pests and diseases into the country. These cuttings were grown in quarantine for several years.

In the meantime, Brad Stark Jr. went bankrupt and Brad sold the rights to the Griffith family, who owned Suntreat. The development of Dekopon was kept under wraps until they could properly cultivate them and release a branded version, eventually settling for Sumo, presumably due to the fruit’s resemblance to a sumo wrestler. Dekopon fruit must be a certain size to be considered a Sumo citrus.

Due to the difficulty growing Dekopon, it took until 2011 before the fruit was released to the public.

Other countries

Pacific Fresh brought the Dekopon to Australia in 2011 where it is grown commercially at a small level. The ripe fruit is available between June and August in Woolworths stores.  Dekopon is also grown in Brazil, which produces 300g tonnes of fruit per year.

Growing Dekopon

It appears that Dekopon trees are primarily sold to commercial farmers and are not available to the public. Some people have attempted to grow trees from seeds found in the flesh of the fruit, however, the Dekopon has been bred to not produce seedy fruit, so finding seeds is often not possible.

Almost all citrus trees are grafted, to guarantee the tree will be a clone of the parent plant. Citrus trees grown from seed won’t necessarily be the same stock as the parent. However, the Dekopon is polyembryonic, which means the seed produces more than one seedling which is different to that of the parent. If you do choose to grow Dekopon from seed, bear in mind it can take up to 15 years for the tree to produce fruit.

How is Dekopon used?

Dekopon is a versatile fruit that can be enjoyed in several ways.

  • Fresh: Simply peel the fruit and enjoy the juicy and sweet flesh.
  • Juice: Squeeze the fruit to make a sweet juice that can be enjoyed on its own or in cocktails.
  • Liqueurs: Carefully remove the zest from the fruit, without the bitter white pith underneath. Combine the zest with vodka in a large glass jar and let it sit in a cool, dark place for 7-10 days or until the vodka has taken on the Dekopon flavour. Strain the vodka mixture to remove the zest. Make a simple syrup by combining 1 litre of water with 1 kg of sugar, and heat over medium heat until dissolved. Once it has cooled, combine the simple syrup with the vodka mixture to make a Dekopon ‘limoncello’.
  • Desserts and cakes: Dekopon rind, juice and segments can be added to desserts, cakes and icing for a sweet, refreshing taste.
  • Salads: Finely grated zest can be added to salad dressings and fresh fruit segments go well in salads.
  • Marinades: Blend Dekopon fruit with soy sauce, vinegar, honey, and garlic for a sweet and savoury baste for red meat, poultry, or seafood.
  • Sushi: Dekopon can be used as a substitute for traditional citrus as a topping for sushi rolls. The sweet and slightly acidic flavour compliments the salty and savoury flavours of the rice and other ingredients. The fruit is typically sliced thinly and arranged on top of the sushi roll.

How to store Dekopon?

Store Dekopon the same way as other citrus varieties.

  1. Room temperature: Dekopon will last approximately a week at room temperature. Store away from direct sunlight and heat sources.
  2. Cooler temperature: For longer storage, store them in the refrigerator, where they will last for several weeks.
  3. Avoid ethylene: Do not store citrus near fruits and vegetables that produce ethylene gas, such as apples, bananas, and tomatoes, as this can cause the fruit to ripen and deteriorate more quickly.

Recipes

Dekopon simple syrup
Ingredients:

  • 1 cup of sugar
  • 1 cup of water
  • Juice and zest from 1 Dekopon

Method:

  1. Combine the sugar and water in a medium saucepan. Heat over a medium heat, stirring occasionally, until the sugar is fully
    dissolved.
  2. Add the Dekopon juice and zest to the sugar mixture.
  3. Bring the mixture to a slight simmer and allow it to cook for about 10 minutes, stirring occasionally.
  4. Remove the saucepan from the heat and allow the syrup to cool completely. The Dekopon zest will continue to infuse flavour into the syrup as it cools.
  5. Once the syrup is cooled, strain it through a fine-mesh strainer to remove the zest pieces.
  6. Store the syrup in an airtight container in the refrigerator. It should last for about a month.

This syrup can sweeten and add a citrus flavour to cocktails, teas, lemonades, and other beverages. It can also be drizzled
over pancakes, waffles, or desserts for a sweet, citrusy touch.

Dekopon citrus salad
Ingredients:

  • 2 dekopon
  • 1 grapefruit
  • 1 orange
  • 1 tablespoon honey
  • 1 tablespoon mint leaves

Method:

  1. Peel the dekopon, grapefruit, and orange, removing any seeds.
  2. Slice them into rounds or segments.
  3. Mix them in a bowl.
  4. Drizzle honey over the fruit and garnish with mint leaves.
  5. Serve chilled.
Dekopon sorbet
Ingredients:

  • 1 cup dekopon juice
  • 1 cup sugar
  • 2 cups water

Method:

  1. Heat the sugar and water in a pan until the sugar is dissolved, remove from heat and allow it to cool.
  2. Mix in the dekopon juice.
  3. Freeze the mixture, stirring every 30 minutes until it is frozen and fluffy.
Dekopon marmalade
Ingredients:

  • 5 Dekopons
  • 2 cups sugar
  • 1 cup water

Method:

  1. Cut the Dekopons into thin slices, removing any seeds.
  2. Mix the slices with sugar and water in a pot.
  3. Bring to a boil, then simmer for about an hour until it thickens.
  4. Let it cool before storing in a sterilised jar.
Dekopon salsa
Ingredients:

  • 2 Dekopons
  • 1 red onion
  • 1 jalapeño
  • 1 handful of cilantro
  • Salt and pepper to taste

Method:

  1. Dice the Dekopons, onion, and jalapeño and mix them with chopped coriander in a bowl.
  2. Season with salt and pepper.
  3. Let the salsa sit for 20 minutes before serving to allow flavours to combine.
Dekopon chicken
Instructions:

  • 4 chicken breasts
  • 1 Dekopon
  • 1/4 cup soy sauce
  • 1/4 cup honey
  • 1 garlic clove
  • Salt and pepper to taste

Method:

  1. Squeeze the juice from the Dekopon.
  2. Mix it with soy sauce, honey, and minced garlic.
  3. Season the chicken breasts with salt and pepper, then marinate them in the sauce for at least 30 minutes.
  4. Grill or pan-fry the chicken until cooked through.
Dekopon lemonade
Ingredients:

  • 1 cup fresh Dekopon juice
  • 1 cup Dekopon simple syrup (from recipe 1)
  • 4 cups cold water
  • Ice

Method:

  1. Combine lemon juice, Dekopon simple syrup, and cold water in a pitcher.
  2. Stir well and serve over ice, garnishing with Dekopon or lemon wedges.
Dekopon cake
Ingredients:

  • 2 Dekopons
  • 1 1/2 cups self raising flour
  • 1 cup sugar
  • 1/2 cup butter
  • 2 eggs
  • 1 teaspoon baking powder
  • 1/4 teaspoon salt

Method:

  • Cream together the butter and sugar.
  • Beat in the eggs.
  • Squeeze the juice from the Dekopons and grate their peel.
  • Mix the juice and peel into the butter mixture.
  • Combine the flour, baking powder, and salt, then mix them into the wet ingredients.
  • Pour the batter into a greased cake pan and bake at 180°C (350°F) for 35-40 minutes.
Dekopon panna cotta
Ingredients:

  • 2 Dekopons
  • 2 cups of heavy cream
  • 1/2 cup of sugar
  • 1 tablespoon of unflavoured gelatin
  • 3 tablespoons of cold water
  • 1 teaspoon of pure vanilla extract

Method:

  1. Zest one Dekopon and squeeze the juice from both. You should have about 1/2 cup of juice. Set aside.
  2. Pour the cream into a saucepan. Add the sugar and Dekopon zest. Heat over medium heat, stirring occasionally, until hot but not
    boiling.
  3. While the cream is heating, sprinkle the gelatine over the cold water in a large bowl and let stand for 5 to 10 minutes.
  4. Once the cream is hot, pour it over the gelatine mixture, and
    stir until the gelatine is completely dissolved.
  5. Mix in the Dekopon juice and vanilla extract.
  6. Pour the mixture into 4 to 6 ramekins or custard cups.
  7. Let them cool slightly, then cover with plastic wrap and refrigerate until firm, about 4 hours.
  8. To serve, you can either unmould the panna cotta onto plates or serve them in their cups.