Kafenol 327 is simple :
Water to fill 11 US fl oz
Washing soda (Na2CO3) 3 teaspoon
Ascorbic Acid (E300) 2 teaspoon
Instant coffe (brazero) 7 teaspoon
This will be enough for one tank 35mm film
Develop for 15 minutes @ 20 deggree centigrade as a starting point.
For extended use, one of course need to increase development time, just as with D76 and other commersial developers.
I have come up with a combined regime for extending times and replenishing the brew from film to film. This has been suggested by others, its not for me to brag about, but I don't think others have put it into system.
Add one teaspoon of instant coffe per film, after the first.
Add one pinch of Ascorbic acid (Vitamin C powder) per film, after the first.
This a very simple, reliable procedure and takes no time, it is easy to develop films in straight succession, just save the developer, add the replenisher and top up volume to 11 oz.
This is a little more involved.
General procedure, increase development 15% from the previous time, thusly :
Start time = T
T , Tx1.15 , (Tx1.15)x 1.15 , .......
Example generic B&W film, T = 15
15, 17.25 , 19.9 , 22.9 , 26.3 , 30.2 , 34.7
I hace come to the conclusion that films from different manufacturers need different starttimes, and hence a different time table.
I do a lot of cross-processing, developing C41 color-negative film as B&W, different colorslide films as B&W, including old Kodachrome, which should be cheap the coming year...
Kodak Gold 200 needs ca 16 minutes as a starting point
Fuji Superia 100 needs more time, 19 - 20 minutes in my experience (my first tries with Fuji and the then recommended 12 minutes was failures, longer times fixed that)
The following time-tables are recommended:
Kodak Gold 200, T=16
16, 18.5, 21.2, 24.3, 28, 32.2, 37
Fuji Superia 100, T= 19
19, 22, 25.1, 29, 33.2, 38.2, 44
NB! There is no problem switching from filmtype to filmtype, just determine a starting point, and calculate a time-table for your film.
And you can do this as you go:
For instance start with 2 Fuji films, follow the timetable, then switch to standatd (B&W) films and read off the time for film #3, then switch to Kodak Gold 200 (or other Kodak C41 films), read off time for film #4 and so on.
I have tried this for myself, mixing films with excellent results, pictures from this 4 successive films will be shown here.