Season of Hiyaoroshi & Akiagari: the Aroma and Taste of Autumn

With the transitioning of Summer to Autumn in Japan, Japanese maple trees take on rusty red, mustard and ochre tones 紅葉, rice paddies turn golden with the harvest of plump and ripened rice, and the humidity of the tropical heat is replaced with a soothing chill.
Seasons are ever so culturally important to the Japanese and with each comes new delicacies and traditions. 
This season is not only a time when the new sake brewing year kicks off on October 1st, but it’s also when a highly anticipated style of Sake become available.
Tis the season of the Hiyaoroshi ひやおろしand the Akiagari 秋上がり。These are batches of brews which have been laid to rest in a cool spot in the brewery after fermentation, pressing and once pasteurizing, through Spring and Summer, awaiting release. Over time they have taken on a mellow personality but still maintain a lively quality.
The major agreed upon difference between an Akiagari and a Hiyaoroshi is this; an Akiagari generally seems to be pasteurized a second time before release whereas a Hiyaoroshi is only pasteurized once before storage, essentially a Namazume or so the general rule of thumb goes.
Akiagari is a less seen term on the bottle these days but the Hiyaoroshi has really caught on and is increasingly sought after. Sake drinkers wait in anticipation all year for this special type to become available.
Semantically these are funny terms that carry some meaning that takes some imagination.
For example, Aki means Autumn and Agari mean to raise up. These 2 words together can connotate Autumn cleaning or clear Autumn weather.
Hiya means cold and Oroshi means to lower, in this case it can be seen to signify taking the sake out of the large tanks and lowering it into the casks for release when its cold. Historically, this was because the brewers waited till the weather cooled down to release the Namazume as they would easily spoil in the heat of Summer without the second pasteurization to kill all the active enzymes.
One is to raise up and one is to lower.
These terms are not legally binding and there is some flexibility to them however, what you can expect is this, they are absolutely delicious. Their aromas tend to be more subdued than a freshly pressed sake, flavours more mellow, their texture might be more silky and the time spent maturing often allows more development of amino acids.
They pair superbly with warming dishes, stews full of fall delights like mushrooms and sweet potatoes, oily fish like pacific Sauri, and chestnuts which have a flavour akin the koji used for sake making. They are also very often enjoyed warmed, which admittedly isn’t quite as soothing in the heat of Singapore at this time, but wonderful on a wet rainy evening.