BeerBorg

A little experiment I tried and have had great results with is using some of the leftover yeast cake to make a sourdough starter. I started by using about 4 Tbs. of the Notty from our RCE after harvesting some for future brews. Then I added 2 Tbs. of active yogurt for the lacto bacteria and 1 cup of all purpose flour and a half cup of water. After 24 hrs it had doubled in size and was bubbling away. I took half to make pretzels and replaced with 1/2cup of flour and 1/4 of water. Repeat this every day. The first loaf of bread and pretzels were bitter due to hops being in the yeast cake, but after 1 week that has vanished to yield a wonderfully flavoured starter. It takes a little longer to rise than conventional active baker's yeast, but works just the same. I make a batch at night and put in in a covered bowl in the cold oven overnight, punch it down in the morning and shape into loafs for pans or free artisan style loafs or just let rise again to roll out for pretzels later. just before dinner take the 2nd rise dough from oven, preheat to 400 and put the loaves back in for about 30 min.
I just added some of the Belgian cake when racking to secondary. Added flavor and complexity for the bread.

how often do you have to bake to keep the starter viable? Every time I’ve made sourdough starter, I burned out on trying to remember to feed it.

If you are going to use it daily then feed it when/after you take some for that day's baking and just leave it sit at room temperature. If you keep it in the fridge then you can just give it a small feeding weekly because the yeast will be in a semi-suspended state. Take them out the day before you want to use them and give a full feeding at room temp that should double in size in 12-24 hrs. Hope this is helpful. It is like making a yeast starter for the beer in that you want more numbers in an active state before pitching.