Mike's right but I'll add. Glass bottles (actually, even clear glass have caused me no problems as long as not stored in sunlight) filled all the way up and SECURELY capped will allow ANY (yes, ANY) developer to last indefinitely without discoloration. I Have had RA-4 dev mixed since 2003 as a test and still good as new. Also, a bonus, those clear, brittle plastic bottles (Gatorade, Sodas, Juices) are AS GOOD for such storage and are available everywhere free (at least in all Philadelphia trash cans and with cap even!). This handy bit of information I discovered on my own about 10 years ago. Don't use the softer plastics like those for milk containers. The CLEAR, BRITTLE plastic (ie, high density plastic). If carbonation is sold in it, it is good but, of course, it could be sold with other than carbonated drinks like, as I said, GatorAde and most juices. I repeat emphatically, though, the bottles MUST be filled up to the very rim. For most bottles clear glass marbles can take up the slack to remove all sir space because the brittle nature of this high density plasctic precludes being able to squeeze these bottles without potential damage being done to the plastic. Very, very handy for small quantities (about 54ml) are those tiny plastic liquor bottles (metal caps ones on these tiny bottles are the best because the plastic cap ones oftentimes do not make a secure seal.) - David Lyga