Since the upcoming DF update is going to involve hygiene and soap may actually be useful, I've been considering alternative cleaning products for those who the lack resources.
BackgroundSaponaria (Soapwort) has been used as cleaning product for centuries in this world. The roots and leaves are crushed and mixed with water to produce a lather. It grows well in temperate climates. The root is dug up in Autumn while the flowers are collected in spring.
Dwarf Fortress - How Soapwort could fit in.-It could be found by plant gatherers on temperate and/or forested maps or could be brought as plants/seeds by humans or elves who have this in their territory.
-Since crops can't be grown across seasons, I'm thinking it could be viable to grow spring-summer-autumn and the roots/leaves are harvested.
- Plant would be processed into bags or something in farmer's workshop or milled.
-The alchemist's labratory could be used to create the lather. A bucket of water would be needed+ 1-2 soapwort root/leaves for the reaction. Alternatively if there is a bathing related workshop it could be made there because of difficulty in obtaining glass vials.
-To offset the relative ease of obtaining soapwort:
- Soap bars could be a more powerful cleaner.
- Soap bars can be stored. Once soapwort is used to make a lather it has to be used immediately. Although when stored as roots soapwort can last awhile.
- Soap Bars could be used several times. Once made soapwort lather has a single use per a unit.
Useful linksSaponaria - WikipediaSoapwort - Herbs2000History and Culture of SoapwortEDIT: Added another offset