I've reused oil before. I had a leaky oil filter on my motorcycle that needed to be changed. I cleaned out the pan and cleaned around the filter and drain plug. Drained the oil into the clean pan, replaced the filter and poured the oil back into the engine. No problems.
You just need to keep it in a clean container if you're going to save it for later use.
You just need to keep it in a clean container if you're going to save it for later use.