Why Do Scalloped Potatoes Have A Liquid Consistency?

Scalloped potatoes have a creamy, rich texture with a savory flavor. A common problem that many chefs face is having watery, scalloped potatoes. Understanding why that happens is key to perfecting the scalloped potato recipe. This article explores the various causes of watery scalloped, mashed potatoes and provides tips for ensuring your dish comes out perfectly creamy each time.

Basics On Scalloped Potatoes

Before you can understand the cause of watery scalloped potatoes, it is helpful to first know what makes this dish so special. A classic recipe of scalloped, mashed potatoes typically contains thinly sliced potatoes and a creamy cheese sauce or milk-based sauce. Layer these ingredients in a casserole dish and bake until the sauce thickens and bubbles and the potatoes become tender.

Common Causes For Watery Scalloped Potatoes

Incorrect Potato Choice

  • Starchy Vs. Waxy Potatoes: Starchy Russets potatoes release more starch and break down faster during cooking. Waxy russets, such as Yukon Gold and red, retain their shape but release a lesser amount of starch. This could result in a more watery dish.
  • Solution: Use russet potatoes for a creamier result.

Inadequate Thickening Of The Sauce

  • A Sauce Without Thickener: If you simply combine cream or milk with potatoes without using any thickener, the sauce will be very watery. The sauce will not have the creamy texture it needs without a thickening substance.
  • Solution: To thicken your sauce, add a roux before you combine it with potatoes. The sauce will stay thicker during baking if you use this method.

Too Much Moisture in Potatoes

  • Water Content In Potatoes: Potatoes have a lot of water. It is released into the cooking process and can dilute the sauce.
  • Solution: After cutting the potatoes into thin slices, consider par-cooking or pre-cooking to release some of the moisture. Then, layer them into the dish. It can be helpful to salt the potato pieces and let them sit before blotting.

Overcrowding The Baking Dish

  • Insufficient Heating Circulation: Overcrowding can prevent heat from being evenly circulated, causing the potatoes to steam rather than bake. This can trap moisture, resulting in a watery end result.
  • Solution: Layer the potato pieces evenly, and don’t overload the dish. Use a large baking dish if you need to for proper heat dispersion.

The Wrong Cooking Time And Temperature

  • Low Temperature, Short Baking Time. Baking too low a temperature or not long enough will prevent the sauce from thickening.
  • Solution: Bake scalloped potatoes for the appropriate amount of time. Usually 1 to 1.5 hrs. This allows the potatoes and sauce to cook thoroughly.

Enhancing Your Scalloped Potatoes Recipe

You can improve the recipe by adding these additional tips:

  1. Use Cream or Half and Half: Substituting half and/or heavy cream with milk can produce a richer sauce.
  2. Add cheese: This will enhance the flavor of your sauce and also help to thicken it. Cheddar cheese, Gruyere cheese, or Parmesan is a great choice.
  3. Layer with Precision: Make sure the potatoes and sauce are evenly layered. Pour a small amount of sauce on each layer of potato to ensure uniform distribution and consistent cooking.
  4. Cover: Cover the dish before baking to prevent excessive browning or drying. Uncover at the end of the baking process to let the sauce reduce and brown the top.
  5. Rest Before serving: Let the dish sit for 10-15 minutes. This will help the sauce set and become thicker, leading to cleaner servings.

Troubleshooting the system and making adjustments

Even though these tips are helpful, they may not always be enough.

  • The Dish Becomes Too Liquidy Mid-Bake: You can remove some of this excess liquid by carefully spooning it out. Mixing cornstarch into water will also work. Stir it gently in the sauce.
  • After Cooking: If potatoes remain watery after cooking, place the dish in the oven again at a slightly increased temperature. This will help to remove some of that excess moisture.


To achieve the perfect dish, you must pay close attention to every detail. The right potatoes are key, as is thickening the sauce and managing moisture. With these tips and techniques, your scalloped fries will be the star of any meal. You’ll impress family and friends with their perfect texture and flavor.