Your photo inspired me to try again with my Caffenol C-M recipe
I made a batch tonight and added a .5 gram of Sodium Bromide and was very happy with the results. I did a 40 minute stand development, but could have gone to 60 minutes. I had forgotten that when making the batch, to measure the temperature of the mixture because the temp came up almost 9 degrees after mixing.
Hi Greg. I try to keep things steady at 68F/20C if I stand develop. If need be I use a bath of water to keep it level. For stand development I use Caffenol-C-L, and 1 to 1.5grams/litre
Note that for all Reinhold's (caffenol.blogspot.com) recipes its important to know what you are dealing with ingredients wise. Especially if using the C-L version. The ingredient that varies most in quality (and concentration) is the soda (sodium carbonate). Mine is more or less 100% anhydrous (no water content), meaning I use the recipes as they are. Others find that their soda's contain up to 50% water, and have to adjust the recipe accordingly. The soda concentration, and to a slightly lesser degree Vitamin-C, is what regulates how active the developer is. C-C-M and C-C-H are more tolerant of variations, whereas C-C-L is not tolerant at all. The latter I've had a few mishaps with. The first two are too active for stand development, if the concentrations are correct.
To test your how pure your soda is. Weigh a good portion, say 200 grammes or equivalent in Oz's. Then spread out on baking paper and a baking tray and heat in oven at 250F/120C for 30 minutes and weigh again. If its unchanged then its 100% anhydrous, if not factor in how much less concentrated it is when mixing up the brew.
Typical development times for a few of my most used films:
Acros 100 @ EI100 in C-C-M (no bromide): 12-13minutes @ 20C
TMX @ EI 100 in C-C-M: 13-14 minutes @ 20C
Delta 400 @ EI400 in C-C-H (1.2 g/l Potassium bromide): 13minutes @ 20C