RA4 developer is a bit fussy for keeping qualities according to Kodak, but a print from the Feb 2011 test bottle looks exactly the same as one from a fresh mix from yesterday. The tint of the developer is close to being the same as well. I'm using Kodak Supra Endura paper and processing at room temp, without adding a starter to the developer when using steam distilled water to mix the concentrates and storing the mix in a 2 liter soda bottle. From a fresh mix I can get two to four 8x10 prints or equivalents in 4x5 test prints from 70 ml of working solution used three or more times in an 8x10 drum at room temp in a span of an hour or two. Well the year old stuff can do one print in a drum that is visually identical to the previous test prints done over the last year. Three months ago two prints done an hour apart in the same "cup of soup" were visually the same, but not today. The second one is lacking the "sparkle" of the first one, so the developer is on it's way out and is now really a one shot developer. It does keep much longer than Kodak's conservative 6-8 weeks, but a year is pushing it. I'm not complaining, that's for sure, as always YMMV.