The Nifty news site has an article from sake lecturer Chikako Ōkoshi on amazake - and why although it's associated with winter today, that wasn't always the case.
Back in the Edo Period (1603 to 1868) amazake was prized as a kind of nutritional supplement, but it's recorded as a seasonal reference to summer in the set imagery used for haiku poetry.
Ōkoshi extols amazake's virtues as an elixir for recovering from the exhaustion brought on by lingering summer temperatures. The earliest known mentions are in the ancient text Nihon Shoki, where an Ama no tamuzake (天の甜酒, liqueur of heaven) or Ama no bishu (天の美酒, nectar of heaven), and an okome no sake (お米の酒, rice alcohol) made by Konohanasakuya-hime for the Niinamesai harvest festival are both thought to be an alcohol made from rice as an offering to the gods.
In the Heian Period (794 to 1185) amazake was enjoyed by nobility at banquets, and in the Edo period amazake sellers started providing it to the common people as a highly nutritious food. (The article has an image of an amazake seller in a print by Mankō Morisada circulating in the late Edo period.)
Today, amazake is jokingly referred to as the "drinkable IV", hinting that it's as good as medical attention when it comes to restoring the body. Although, as Ōkoshi points out, it might not have been as much of a joke in the times before modern medicine. She also draws attention to the brazier in the illustration of the amazake seller - like sake, amazake was traditionally drunk warm as it was thought to be better for the body.
Ōkoshi comments that she sometimes finds amazake a bit too sweet, and suggests a different way of drinking it - mixed 1:1 with sake. They're both made from rice and kōji - how could they not go together? Mixing them lets you enjoy the sweetness of amazake and freshness of sake all at the same time. [And the obligatory shout out to people "who aren't good with sake" to let them know this is okay for them. Am I the only person who finds this patronising?]
Another tip is to mix amazake and yohurt 1:1 for a creamy amazake dessert. The natural sweetness of the amazake and sourness of the yogurt are a perfect combination.
Amazake contains alcohol when made from sake lees, but not when it's made from rice, rice mixed with other grains, or heirloom red rice. It's gaining popularity in Japan and can be found more and more easily in supermarkets, but Ōkoshi cautions buyers to check the label as many contain added ingredients such as glucose - there should just be rice (米) and rice inoculated with kōji (麹米) listed.
Alcoholic amazake made from sake lees is seasonal, as lees are mostly only available in winter when sake is being produced. But if it's just rice and kōji, it's available all year round - especially if you make it yourself! She gives a recipe for making it at home in a rice cooker.
- Use 300 g of rice kōji for 1 measure of rice. [Rice kōji is available in packets in supermarkets in Japan.]
- Put a bit more water than usual in the rice cooker so as make okayu rice porridge.
- Let the cooked okayu cool to about 60°C, then slowly mix in the rice kōji.
- Hold at around 50°C for about 6 hours.
- When it thickens, it's ready!
- Original article (Japanese, Nifty News, 21 August 2018)