灰
CQ82 really is the 灰 issue, covering types, history, and one instruction for 灰型. In 茶の湯, 5 types of ash are used.
Ash is really not healthy; so when sieving it, you should wear a mask and eye protection!
For 風呂 and 炉, ashes are ideally made of oak (Quercus acutissima or serrata, though I'd really rather use the latter for storing whisky in it); but, kindly enough, they say that pine or any other wood are satisfactory 🤷♂️ Or, as 織部 did, you use ash from the Uji tea driers. Or, as Fabio does, get it from a Pizza restaurant.
- 風炉灰 also called silky ふくさ灰
- 炉灰, which is the same (but coarser) as above, but coloured with cloves and ばん茶
- フジ灰 (white wisteria ash)
- わら灰 (藁灰) (straw ash)
- ヒシ灰（菱灰） (red caltrop ash)
There's also a lecture by Kimura, where he explains a little bit about ash and 炭.
| 風炉 | 炉 |
|---|---|
| 80 holes per cm² | 40 |
| only sieved | sieved and washed |
| not coloured | coloured |
| stored dry | stored in air-tight ceramics so it stays moist all year |
ふくさ灰
Sieved and washed, that means, put in a bucket, pour water on it, churn and skim off debris. Strain, dry in the sun; repeat; then finally put through a silk sieve (see video below).
☝️ Sieved with 80 holes per cm²
When 風炉 ends, ash should be sieved and stored in an air-tight container; and used over and over again until it becomes greenish-yellow.
炉灰
The ashes for 炉, however, are not stored in an airtight container, but in a ceramic jar; and then in the summer it is treated: Washing, coarse sieving, and sprinkled while drying with clove or ばん茶.
☝️ I probably would've just washed it in clove juice, and then dried, but someone in Hurtebise 22 said it might grow mould in this way.
☝️ Sieved with 40 holes per cm²
☝️ Someone on discord said they are stored in sake barrels, which I like.
フジ灰
Made burning from wisteria (フジ) bean pods; or dried cedar needles (then it's technically せん香灰, incense-stick ash). So clean, sometimes some ふくさ灰 is mixed in to make it more interesting.
At the beginning of summer, you use less; toward the middle you use more, and towards the end less again. Always add this just before you begin, not the night before.
わら灰
Made by soaking straw, ideally wheat or rice, remove husk and soak in salt water for one hour. (About 70 grams salt per litre, to stiffen them up.) Half-dry the straw and bake in an almost airtight container until no smoke emerges any more. Open only when cooled down, otherwise they will ignite. ( See example.)
Used for the やつれ風炉 in October, by forming the ash with the 二もんじ, and putting it on top with tweezers, cutting each piece to size. Also used for the round がん炉 in the 水屋; and hand-warmers, in which case it is powdered or broken.
ヒシ灰
Reddish ash made by roasting the shells of caltrop nuts (Trapa japonica, Wassernuss in German, ヒシ in Japanese) and grinding them; used for charcoal for 香 and on the タバコ盆. Could be mixed with fresh, uncoloured ふくさ灰 to colour it a bit; but that'd be cheating.
Palm ash
Strictly not part of 茶の湯, but Christians use the ash from previous year's Palm Sunday on Ash Wednesday just before lent; it might be a cute idea to use it, too.
Flexions
風炉の七歪 or 七つひねり, differs from school to school, but here's a set of rules, mostly from the Almanac, that seem to make sense to me:
1. 風炉 turned towards guests (this one everyone seems to agree on) 2. 釜 turned away from guest 3. 五徳 slightly forward 4. 釜 slightly backward (far side higher) 5. 前瓦 away from guest 6. 灰型 highest in front left, lowest in back right 7. 柄杓 a bit towards the guest