The night before you plan to make the waffles, combine: sourdough discard, flour, milk, lemon juice and honey. Cover and leave on the counter overnight.
The next morning, add remaining ingredients and whisk until fully combined. Plug in your waffle iron. Place a cooling rack over a baking sheet for keeping waffles as they finish.
Spoon batter onto waffle iron (about 1/4 cup if using a mini waffle iron), close and cook until golden brown; about 4-6 minutes per waffle.