Perfect Scalloped Potatoes Recipe: Step-by-Step Guide

Perfect scalloped potatoes require thinly sliced potatoes layered with a creamy béchamel sauce, baked at 350°F (175°C) for 60-75 minutes until tender and golden. The key to success is using starchy potatoes like Russets, making a proper roux-based sauce, and allowing 15 minutes of resting time before serving for optimal texture.

There's nothing quite like a perfectly baked dish of scalloped potatoes—creamy, comforting, and ideal for holiday feasts or weeknight dinners. Unlike common misconceptions, authentic scalloped potatoes don't contain cheese (that's au gratin), relying instead on a rich béchamel sauce to create that signature creamy texture. After testing dozens of variations in my kitchen, I've perfected a method that guarantees tender potatoes with a beautifully golden crust every time.

Why This Recipe Works

Many home cooks struggle with scalloped potatoes that turn out either watery or dry, but understanding the food science behind the dish solves these problems. The secret lies in proper sauce preparation and potato selection. When potatoes release starch during baking, it thickens the sauce naturally—but only if you start with the right foundation.

Potato Variety	Best For Scalloped?	Why
Russet (Idaho)	✓ Best choice	High starch content creates ideal creamy texture
Yukon Gold	✓ Good alternative	Natural buttery flavor, moderate starch
Red Potatoes	✗ Not recommended	Waxy texture prevents proper sauce absorption
Sweet Potatoes	✓ For variation	Creates distinct flavor profile, requires recipe adjustments

Essential Ingredients Explained

The magic of scalloped potatoes happens through careful ingredient selection. Each component serves a specific purpose in creating the perfect texture and flavor balance.

Creamy Sauce Foundation

A proper roux (equal parts butter and flour) is non-negotiable for authentic scalloped potatoes. According to the USDA Food Safety and Inspection Service, cooking the roux for 2-3 minutes eliminates the raw flour taste while ensuring proper thickening power. Whole milk works best for richness without curdling, though you can substitute half-and-half for extra creaminess.

Potato Selection Matters

Historically, scalloped potatoes evolved from English potato pie recipes brought to America in the 1800s. Early versions used whatever potatoes were available, but modern food science shows starchy varieties like Russets create the ideal texture. Their high starch content swells during baking, thickening the sauce naturally as the potatoes release moisture.

Step-by-Step Preparation Guide

Preparation Phase (15 minutes)

1. Preheat oven to 350°F (175°C) - this precise temperature prevents sauce curdling while ensuring thorough cooking
2. Prepare potatoes: Peel and slice Russets to 1/8-inch thickness using a mandoline for consistency
3. Prevent browning: Soak slices in cold water for 10 minutes, then drain and pat completely dry

Sauce Creation (10 minutes)

4. Melt 4 tablespoons butter in a saucepan over medium heat
5. Whisk in 1/4 cup all-purpose flour to form a smooth roux, cooking for 2 minutes
6. Gradually add 2 1/2 cups whole milk while whisking constantly to prevent lumps
7. Add 1 teaspoon salt, 1/2 teaspoon black pepper, and 1/4 teaspoon nutmeg
8. Cook until thickened (about 5 minutes), stirring frequently

Assembly and Baking (75 minutes)

8. Arrange 1/3 of potatoes in greased 9x13-inch baking dish
9. Pour 1/3 of sauce over potatoes, spreading evenly
10. Repeat layers twice more, finishing with sauce
11. Cover with foil and bake 45 minutes
12. Remove foil and bake 25-30 minutes until golden and bubbly
13. Crucial resting step: Let stand 15 minutes before serving to set the sauce

Troubleshooting Common Issues

Even experienced cooks encounter problems with scalloped potatoes. Understanding these context boundaries will help you adapt:

Soggy Potatoes Solution

If your potatoes turn out watery, you likely didn't cook the roux sufficiently or used waxy potatoes. The solution: increase roux cooking time to 3 minutes and always use Russets. For immediate correction, return the dish to the oven uncovered for 10-15 minutes to evaporate excess moisture.

Dry or Curdled Sauce Fix

High oven temperatures cause dairy to curdle. Maintain 350°F maximum and ensure your milk is at room temperature before adding to the roux. If sauce separates during baking, carefully whisk in 2 tablespoons of heavy cream to restore emulsion.

Delicious Variations

Once you've mastered the classic version, try these chef-approved adaptations:

Herb-Infused Scalloped Potatoes

Add 2 sprigs fresh thyme and 1 crushed garlic clove to the milk while heating. Remove before assembling. This technique, used in professional kitchens, infuses subtle flavor without overpowering the dish.

Dairy-Free Option

For lactose-intolerant guests, substitute unsweetened almond milk and use olive oil instead of butter. Add 1 tablespoon nutritional yeast for cheesy flavor. Note: cooking time may increase by 10 minutes as plant-based milks behave differently.

Serving and Storage Tips

Scalloped potatoes pair beautifully with roast meats, especially turkey or ham. For optimal presentation, garnish with fresh parsley just before serving. Leftovers keep well for 3-4 days in the refrigerator—reheat covered at 325°F with a splash of milk to restore moisture. Freezing is not recommended as the sauce texture deteriorates.

Frequently Asked Questions

Can I make scalloped potatoes ahead of time?

Yes, assemble the dish completely, then refrigerate covered for up to 24 hours before baking. Add 10-15 minutes to baking time if starting from cold. Do not bake then refrigerate, as this creates texture problems.

Why are my scalloped potatoes still hard after baking?

This usually happens when potato slices are too thick or oven temperature is too low. Use a mandoline for consistent 1/8-inch slices and verify your oven temperature with an independent thermometer. Potatoes should reach 205-210°F internally when properly cooked.

Can I use pre-sliced potatoes from the grocery store?

Freshly sliced potatoes work best as pre-sliced versions often contain preservatives that affect texture. If using pre-sliced, soak in cold water for 30 minutes to remove excess starch and improve sauce absorption.

What's the difference between scalloped potatoes and au gratin?

Traditional scalloped potatoes use only a creamy béchamel sauce, while au gratin includes cheese between layers and on top. Scalloped potatoes originated in America as a simpler preparation, while au gratin has French culinary roots.