What do you do with leftover mashed potatoes? The test kitchen at King Arthur flour has published a fantastic baking book full of surprising and interesting recipes from easy to professional-grade, so I picked it up yesterday. One of the recipes that caught my eye was a recipe for potato waffles using leftover mashed potatoes. I gave it a shot and found it worth sharing. I’ve added a couple notes and observations as well.

Potato Waffles

This recipe is adapted from The All-Purpose Baker’s Companion from King Arthur Flour company. (Of note, they’re the only flour company that posts the exact protein content on their bags of flour, which is very helpful if you’re a more serious baker.)


  • 1.5 c. (320 g) leftover mashed potatoes
  • 1 tsp. salt (omit if your mashed potatoes are already salted)
  • 2 eggs, separated (Put the yolks in one small bowl, and the whites in another.)
  • 4 tbsp. butter, melted
  • pepper to taste
  • 2 c. buttermilk (See note.)
  • 1.5 c. (180g) all-purpose flour
  • 1 tsp. baking powder
  • 1 tsp. baking soda
  • 6 slices bacon, cooked and chopped


  • waffle iron
  • spatula or fork to retrieve the waffle
  • pastry blender (optional, but it makes mixing potatoes easier)
  • whisk
  • rubber or silicone spatula
  • mixing bowls of varying sizes


  1. In a medium bowl, combine potatoes, salt (if using), egg yolks and melted butter. Mash and mix until smooth and free of lumps. The pastry blender works great here.
  2. Mix into a semi-paste using either a pastry blender or your hands. You want an even mixture with no concentrated areas of spice, egg, or cheese. Make sure you can’t tell there’s flour in it by the time you’re done mixing.
  3. In a separate bowl, whisk together flour, baking powder, baking soda, and bacon.
  4. Add the dry ingredients to the wet ingredients, folding with a silicone or rubber spatula until the flour is just incorporated.
  5. Beat the egg whites with a whisk until foamy and a bit stiff. This will take longer than you think, perhaps a few minutes. If you have an electric hand mixer, use it here to make this step more convenient.
  6. Fold the whipped egg whites into the potato/flour mixture.
  7. Bake waffles according to your waffle iron instructions. Different irons are different sizes, so check the manufacturer’s instructions for the amount of batter used per waffle. I use 1/2 to 3/4 cup in mine.
  8. Serve with butter and a side of fruit.


  • One thing that isn’t mentioned in this recipe is the type of mashed potato. I use Yukon Gold potatoes when I make mashed potatoes, because they yield a very creamy mashed potato. However, when I bake potato rolls or a potato bread, I use russet potatoes due to their far higher starch content. Russet potatoes will have a drier and fluffier texture when cooked than Yukon gold. As a result of using Yukon gold potatoes, my waffles came out very velvety and creamy, but deflated to almost as flat as a tortilla after a few minutes on the plate. The next time I make these, I think I’ll use some of the leftover mashed russet potatoes from making potato burger buns to see if I can get fluffier waffles.
  • The book mentioned using the food processor to combine the wet ingredients in step 1. I do not recommend this. It’ll make your potatoes too “glue-y.”
  • Buttermilk is called for on purpose. You want a more acidic milk to react with your leaveners to help the waffles rise. You can clabber regular milk into “buttermilk” for baking purposes by adding 1 tbsp. lemon juice or apple cider vinegar per cup of milk. You can use immediately; a rest isn’t necessary.
  • I also add sour cream to my mashed potatoes when I make them as a side dish. I think that resulted in too wet a batter for my waffles, so I didn’t get the nice crispy exterior we usually like in American-style waffles. If this is the case for you, add perhaps 1/4 c. extra flour to the recipe.