This is a recipe my grandmother gave to me and I believe she got it off a bag of Quaker Oats. It is the best bran muffin recipe I have tried. I misplaced the recipe and couldn't find it online anywhere, so I'm posting it here so I can find it. I remember my grandmother making these when we'd go to stay with her and I loved them. I usually store the unused batter in plastic containers in the refrigerator. I fill the containers with the batter and then put a layer of plastic wrap over the top before I put the lid on...I find the batter keeps longer that way. Also, by putting it in a couple of smaller containers, rather than one large one, the batter keeps longer because you aren't exposing it until you use it. I'm not sure exactly how many muffins this will make because I've never made them all at once, but it makes alot.