I was asked just today where my starter recipe was so I thought I woudl respond with another post to tell about that.
Starter recipes are all over the internet and keeping them going is fairly easy. The thing is, you have to keep them at the right temperature and no warmer or bad bacteria will grow and ruin your sourdough starter.
If you see any color of dough besides your dough color that you already have such as green, blue, black on the inside of the jar or the inside top of the lid then you know something went wrong.
You can not leave your starter jar in a temperature above 80 degrees. So that means that you don't want to set your thermostat close to 80 because that will be living dangerously. Or if you do make sure that you are intermittently putting your sourdough into the refrigerator to cool. It hard for me to do this because its good to have your sourdough up to room temperature before you add it to your recipes and I use it almost every day. So I try to keep my thermostat between 75-77 degrees, so that I can keep it on the counter top. If for some reason I have it warmer I will refrigerate. Also it matters where you keep it on the counter top. Do not keep it next to your stove. The heat may kill it there as well.
1 cup of white wheat flour
1 cup of water
1 tsp of apple cider vinegar
Add equal amounts of flour and water every 8 to 12 hours until it is bubbly (in my house that is about 3 days)
Make sure that you have fed (added to) your starter 3 times in these 8-12 hour periods before you use your starter. I usually just add a table spoon or so of each flour and water after the first cup. There will be a little extra water or hooch they call it above your starter and you can just mix that in or pour it off as you choose it is healthy and won't hurt your starter at all. It is the alcohol that is produced from the fermentation and cooks out during baking.
I hope this answers all of your Sourdough questions. I am no expert but I want to share what I know.
Have you ever made sourdough starter on you own?
Here is another recipe I have used before with success, How to make Sourdough from Scratch.