I'm still pretty new to brewing, but I have been pretty excited about washing my yeast and reusing them.
I forgot to prepare to wash yeast as described at http://www.homebrewtalk.com/f13/yeast-washing-illustrated-41768/. I also made the wife and I late to somewhere by brewing that day. So I was in a hurry to get the wort to fermenting and leave.
Do to that, I poured a gallon or so of the boiled water I had into the carboy to cover the yeast. The next day I followed the directions from the link above. However, I don't have a massive jar and didn't want to boil water again, so I used a 3qt apple juice container (left over and cleaned from making Apfelwein) and sanitized it and the pint jars with Star-san. The only difference is that I dumped some of the water off the top of the yeast cake since it had settled the whole night before.
I was planning on brewing the weekend before this last one. So I took one of my pint jars of washed yeast and made a starter with the 1/2 cup DME and 2 cups of water method. I put it in the apple juice container (above and resanitized with Star-san), shook it up real good, and covered with a new piece of tin foil. If fermented over the course of two days. On the third day I realized I wasn't going to be able to brew. So I put it in the fridge.
I once again thought I was going to be able to brew this last weekend, and had a similar situation again. I decanted some of the liquid on the top of the yeast in the bottle and did the 1/2 cup DME - 2 cups of water thing and let it ferment for a couple of days.
1. Can I put this starter in the fridge and build it up again before I [attempt to] brew again, or should I just throw it out and start over?
2. Was it okay to leave the yeast covered in boiled (and cooled back down to room temperature) water overnight instead of using water that has been refrigerated?