Hi Megan, you certainly didn't ruin your starter by failing to discard. However, you may notice that your starter ferments and ripens a bit faster because there are more sourdough organisms present to consume a relatively smaller amount of fresh flour and water. The number of twice a day feedings you'll need to do all depends on how your starter behaves. What you're looking for in a fully developed starter is for the starter to double predictably within about 6-8 hours after a feeding. Once you see this kind of consistent rising behavior, that's a good sign that your starter is fully mature and ready for bread baking. 

As far as discarding goes, for our sourdough starter feeding routine you want to discard all but 1/2 cup (113g) of starter, and then feed that 113g of starter with 1/2 cup (113g) water and 1 scant cup (113g) Unbleached All-Purpose flour. Once your starter is bubbling nicely and has a good aroma you can begin to save the discard in a separate container in the refrigerator and use it in recipes calling for discard. The discard will last in the refrigerator for a few weeks, but it does get thinner in texture and funkier in flavor as it ages, so I typically throw it out and start fresh every few weeks. 

• Reply