You just learned to make a smaller amount and make more if you need it. I always seem to have a little left over and I always have some fabric to iron or a few blouses. After a few tries you will be able to estimate the amount you need and mix that much. You will also learn than you can mix it so it has light body when you test iron a scrap and add more starch to the water to adjust the crispness you want. You can always start light and add more, you can't go the other way.
Starched material will not go bad. I usually only starch as I cut and I have never experienced bugs. Even when leftover fabric goes into the stash.
Storing dampened fabric in the fridge should only be for a few hours to overnight. It may mold if left longer.
Liquid starch will keep in the fridge for a month or more.
peace
Last edited by ube quilting; 07-17-2013 at 12:30 PM.