Consider discard as wet flour. You know how much water and how much flour you used. It might have evaporated a little, but not enough to make a huge difference. You can use discard in just about any recipe that wants that much flour and water together, and just do the sums to see how much more of each to add. If your discard is particularly sour tasting, add a pinch of sugar. It doesn't take a lot. Because of the differences in absorption and aeration, however, discard is difficult in cakes. Until you're really comfortable using it, I'd avoid anything you want to be light and fluffy.

Here's my waffle recipe. My discard jar has white and whole wheat together. If your starter is wheat of any kind, it'll work. Rye needs a different recipe. The active starter can be new discard if it was fed recently. If the starter has been languishing in the fridge, feed it up including what you would discard, and discard after, taking your 3+ TBSP from that. The malt is for flavor and has some sweetness. You can sweeten to taste, maybe a half teaspoon of sugar instead, and add whatever flavoring you like. The buttermilk powder helps activate the soda and tenderizes the crumb. You could use a little liquid buttermilk, or milk and baking powder instead of soda, or just baking powder instead of soda. I've stopped using the butter for a fluffier waffle. Both ways are good.

Sourdough Discard Waffles

1.5 c. discard, half white, half wheat

3 heaping TBSP active starter

1 tsp. baking soda

1/2 tsp. salt

1 (2?) heaping TBSP buttermilk powder

2 heaping TBSP malt powder

2 eggs

1/4 c. melted butter (optional)

Sprinkle dry over wet wheat (discard).

Add eggs and butter. Stir.

Slightly more than one waffle ladle for one waffle (round Belgian).

I make the sourdough discard crackers from the King Arthur website; it uses up a full cup. You can add your own choice of seasonings and herbs both in the dough or sprinkled over top. They also have a recipe for crumpets (or pikelets for a free-form version). My favourite use of discard is for focaccia. You can also make scallion pancakes with the discard.

I noticed a lot of sourdough tutorials call for maintaining a huge amount of starter. If you find yourself overwhelmed by the amount of discard, consider keeping just a small amount, like a Tbs or two.

Plllog where do you buy malt powder? I haven’t seen it when I’ve ordered groceries. I would love to try your waffles! Is this also what you use for bagels?

You can make the waffles without the malt powder. Perhaps add a little sugar because malt is sweet (diastatic malt is basically a sweetener). I have both malt extract powder and diastatic malt powder on hand. I doubt you want three pounds, but this brand of extract powder on Amazon is really good--if you leave it too long (years) it might turn into something akin to plastic, but it'll dissolve in water if you change it out enough times. ;) That's just a caution. It is very good. There's a one pound bag for two dollars less.

https://www.amazon.com/Organic-Light-Dried-Malt-Extract/dp/B007XYH6TY/ref=sr_1_1?dchild=1&keywords=maltoferm&qid=1589851526&sr=8-1

You can also find liquid malt extract in the stores. For powder, try a health food or hippie store maybe. Call and see if they'll deliver or mail. For this purpose you don't want brewer's malt or diastatic. Dry Malt Extract (DME) is the thing. And, yes, you can use it in bagels, pizza, or anything you want that malt taste for. Malt also can help your rise, and is often already added to flour.