Yakusō-yu薬草湯
Not every Japanese bath came from the ground. Yakusō-yu, the herbal bath, is plants steeped in hot water: leaves, roots, fruit and peel. It is as old as the springs and was practised alongside them.
Whole herbs, hot water, time. Nothing else.
The bathing year季節湯
In Edo, the city that became Tokyo, public bathhouses marked the calendar with plant baths. The custom is called kisetsu-yu (季節湯), the seasonal bath, and it never quite went away.
Two are still kept across Japan. Yuzu-yu, whole yuzu floating in the bath on the winter solstice. And shōbu-yu, iris leaves on 5 May, the old Boys' Day, now Children's Day.
The rest of the year, one common calendar runs like this:
| Month | Bath | Plant |
|---|---|---|
| January | Matsu-yu 松湯 | Pine needles |
| February | Hatomugi-yu ハトムギ湯 | Job's tears |
| March | Yomogi-yu 蓬湯 | Mugwort |
| April | Sakura-yu 桜湯 | Cherry bark |
| May | Shōbu-yu 菖蒲湯 | Iris leaves |
| June | Dokudami-yu どくだみ湯 | Houttuynia leaves |
| July | Momo-yu 桃湯 | Peach leaves |
| August | Hakka-yu 薄荷湯 | Japanese mint |
| September | Kiku-yu 菊湯 | Chrysanthemum flowers |
| October | Kaki-yu 柿湯 | Persimmon leaves |
| November | Mikan-yu 蜜柑湯 | Mandarin peel |
| December | Yuzu-yu 柚子湯 | Whole yuzu |
Customs vary by region and household. What holds is the idea: the bath changes with the year, and the year comes into the bath.
At home
Most of these need nothing more than the plant and a cloth bag. Some, like yuzu, go in whole. The herbal soaks we carry come from Japanese makers, and each one tells you exactly what is in it.