I use 20ml autoclaveable vials to make slants for yeast propagation. The method I currently employ is to add sterile wort to the vial and shake it until the yeast is in suspension. I than add the contents of the vial to about 50ml of wort to begin my steps for a starter. My question is can I reuse the agar in the vials? I've recapped the vials and let them sit to see if the culture would grow again but it doesn't. Could I just re-inoculate the slants from the started I just made or is there not enough food left for a new culture? If not, could I reclaim the agar, add more wort, and re-autoclave it to sterilize it and make new slants? I know agar is cheap so the savings is minimal but I like to minimize waste wherever possible. Plus, if I can re-inoculate them that would save a lot of time. How much 1.020 agar is needed for up to 6 months of storage? Maybe I can make 10ml vials and waste less?