Foma Fomadon R09 is a fine-grain liquid negative film developer based on the original formula of Agfa Rodinal. It features high acutance (edge sharpness/contrast) and is designed for manual processing of all types of black-and-white negative films.
It has a very long shelf life and is used in very high dilutions: 1:20, 1:40, 1:50 and all the way up to 1:200. Less diluted concentrate produces harder and more coarse-grain negatives, while highly diluted concentrate yields fine-grain negatives with lower contrast.
If you open a bottle of Fomadon R09 and take approximately 1/2 of the concentrate, the remaining half of the liquid will last about 5-6 months. If you use 1/3 of the bottle, the remaining content will last 7-8 months and if you only take ¼, then you can keep it for about one year. These storage periods are only obtained when the developer is stored in a dark and cold place (10 °C = fridge). Shelf life can be extended dramatically if you pour the non-used (remaining) content of the developer in another bottle with almost no oxygen (use an anti-oxidizing spray). When stored in the fridge, shelf life will be between 20-24 months.