Some of my favorite beers come in 22+oz bottles. Typically these are heavier beers and sometimes, I simply cannot finish the entire bottle in one sitting (maybe I had too much to eat previously. Who knows). Because they are nice beers, I want to enjoy them to their fullest extent, and so I will save the remainder for another night.
How can I prevent these beers from losing any (at least a bare minimum) of their quality once they've been opened? And, does this being opened for a duration -- typically 1 to 2 days -- have a noticeable effect on their quality?