Before you ask, no, this is by no means a traditional Japanese recipe. The Japanese title cited above, さつま芋マッシュ transliterates to satsuma-imo (Japanese sweet potato) masshu (from the English word mashed), and honours my use of Japanese ingredients and flavourings to give a classic dish of mashed starches with dairy fats a memorable umami twist.
My goal for this cooking project was to experiment with using umami-tasting amino acids to enhance the natural sweetness of ingredients. To achieve this, I used Japanese soup stock (dashi) instead of water, mirin instead of sugar or honey and shio koji instead of salt. Let’s explore each of these in more detail:
Dashi (出汁, だし)
Dashi is Japanese soup stock, and unlike French cooking stocks, it takes but a few moments and even fewer ingredients to make. You can think of it as umami magic; a golden liquid that although not very tasty on its own, can transform the dishes you use it in. As Michael Pollan remarks in his wonderful book Cooked: “Nothing about dashi, when tasted by itself, prepares you for what it does in concert with other flavors” (333). He calls it an “italicizer of flavors” and I wholeheartedly agree. The magic of dashi, he explains, comes down to the fact that each of its very few ingredients: konbu (kelp), katsuobushi (dried and smoked bonito shavings), and sometimes shiitake mushrooms, contain one of the main umami amino acids: glutamate, inosinate and guanylate, respectively (Pollan:333). In concert with each other, it’s umami fireworks, plain and simple.
As I have not posted my own recipe for making dashi, I recommend that you head over to Just One Cookbook’s comprehensive page on the subject for some excellent instructions on how to make it. I usually add a few dried shiitake mushroom to the basic awase dashi, by soaking them overnight and using the soaking liquid to make dashi.
Mirin (味醂, みりん)
A pantry essential in the Japanese kitchen, mirin is sweet rice wine, used as a seasoning and glazing agent in cooking. High-quality mirin is made in a process similar to making sake, but whereas sake is made from うるち米 (short-grain rice), mirin uses もち米 (glutinous rice). The result is is syrupy and naturally sweet liquid with low alcohol content.
When shopping for mirin, read the labels carefully, as most bottles labelled as such are not 本みりん (true mirin), but 味みりん (mirin-flavoured), and usually contain added sugars (in the form of glucose, corn syrup, high fructose corn syrup and the like) and other preservatives. They are also not naturally fermented, and so do not have the same umami characteristics as true mirin.
It can be a challenge to find true Japanese mirin in North America, and it would be stocked at a liquor store, not a supermarket. However, if you live in North America, this mirin from Eden Foods is a good option. Traditionally brewed from only water, organic rice, koji and sea salt, it can be found in many health food stores.
Victoria shoppers head to: Lifestyle Markets, Market on Yates, the Local General Store (on Haultain).
Buy Online: here (Amazon)
Shio Koji (塩麹)
Shio koji is a lacto-fermented mixture of rice koji (rice inoculated with aspergillus oryzae spore — the basis for many well-know Japanese ferments such as miso, sake and soy sauce). It provides enzymes and probiotics while imparting the dish with a unique umami flavour. In salads and sauces, you can substitute sea salt, himalayan salt or fish sauce. Shio Koji is also an excellent meat and fish tenderizer, because of the enzymes that break down proteins. To learn more about shio koji, how to make it at home, and how to use it in the kitchen, click
here.
I also sought out the highest quality butter and cream I could find in Victoria. I don’t consume a lot of dairy products, but when I do, I try to choose products that come from sustainably-raised animals, are minimally-processed and have not had any of their fat content removed. In this case, I settled for the Organic Whipping Cream (36% fat) from Avalon Dairy, in Burnaby, BC, and Grass-Fed Butter from Thornloe, in Northern Ontario.
For more information about the benefits of full-fat dairy, check out these articles from Chris Kresser‘s website:
- Dairy: Food of the Gods or Neolithic Agent of Disease?
- Still Think Low-Fat Dairy is the “Healthy Choice”? Think Again!
A Word About Tubers
Lastly, let’s talk about tubers! Tubers are enlarged organs produced by some plant species to store nutrients during the colder or drier months. They are botanically distinct from other underground storage organs such as corms and rhizomes Edible tubers include potatoes (Solanum tuberosum, native to the Americas), yams (various species of the genus Dioscorea, native to various parts of Africa, Asia and the Pacific), cassava (Manihot esculenta, native to South America) and sweet potatoes (Ipomoea batatas, native to tropical regions of the Americas). Somewhat confusingly, in the United States and Canada, we sometimes erroneously refer to orange-fleshed sweet potatoes as “yams” – – but yams denote a variety of tubers that are biologically distinct from anything you might find in your average North American supermarket.
If you have been paying attention, you will have noticed that I have talked of a Japanese sweet potato, but that the only tubers native to Asia are the unrelated yams. Indeed sweet potatoes were not introduced to Japan until the early seventeenth century, when they arrived in the Ryukyu Islands through Spanish and Portuguese trade, after traveling from the New World to the Philippines, and then to Southern China. Other New World crops were introduced during this period, such as pumpkin, tobacco and chili peppers, but none had a greater significance than the sweet potato. It sustained poor farmers during the Tokugawa Era (1603-1867), when for the first time in Japanese history, they could not afford the rice they themselves cultivated, as well as peasants in areas of Japan where the climate did not favour rice agriculture. Furthermore, it became an important source of sustenance for the Japanese people during times of austerity, such as during World War II and in its aftermath.
A trio of satsuma-imo (さつま芋) — Japanese sweet potatoes
Today, there are many varieties of sweet potato in Japan, but the most common, and the one I use for this recipe, is called satsuma-imo (さつま芋). It has dark purple skin and sweeter, cream-coloured flesh, without the beta-carotene flavour characteristic of orange vegetables.
My mashed sweet potato turned out better than I could have expected. Smooth, creamy, rich and sweet, it tasted more like dessert than a side-dish. My umami ingredients really made a difference! I will be making this recipe again, this time for an audience. In the meantime, I don’t mind eating the whole dish by myself.
One last tip: don’t skip the lemon peel! It transforms the dish from rich and delicious into something sublime.
Joëlle
The classic pairing of tubers and dairy fats gets an umami twist, using the amino acids present in Japanese soup stock, shio-koji and mirin to enhance the sweetness of the sweet potato. Side dish or dessert? You choose!
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Ingredients
- 1 medium-sized Japanese sweet potato (about 300g)
- 1/2 cup dashi
- 20g grass-fed butter
- 65g heavy cream
- 1 tbsp mirin
- 1 tbsp shio koji
- Lemon peel, julienned
Instructions
- Wash the sweet potato and cut it into 2-3cm cubes. I did not remove the peel because it is delicious and nutritious, but you may do so if you wish.
- In a small saucepan, bring dashi and sweet potato pieces to a boil and reduce to medium-low heat.
- Add butter and simmer, stirring occasionally, until the sweet potato pieces are tender and cooked through. Add a bit more dashi if the liquid levels get too low.
- Mix in cream and mirin and mash the sweet potato with a fork.
- Remove from heat and mix in shio koji (a silicone spatula works well at this stage).
- Transfer to serving dishes and garnish with julienned lemon peel.
- Serve warm or at room temperature.
Calories
Fat
Carbs
Protein
References
Ishige, N. (2011). The history and culture of Japanese food. New York: Routledge.
Pollan, M. (2014). Cooked: A natural history of transformation. New York: Penguin Books.
