Costco Potato Salad Recipe: Creamy Dill and Mustard Twist

This potato salad delivers the creamy texture you expect from Costco’s version, with a bright dill and mustard twist.

Simple ingredients and a few key techniques create that signature deli-style flavor. The secret is in the balance of tangy and fresh notes.

Ingredients for Costco Potato Salad

Simple, quality ingredients create that signature deli-style creamy potato salad with bright, tangy notes.

The potatoes are non-negotiable here. Yukon Golds give you that perfect creamy texture without falling apart. Most grocery stores carry them year-round, but Costco has great bulk options if you’re making this for a crowd. Look for firm, smooth skins—avoid any with green spots or sprouting. The mayonnaise should be full-fat; Hellmann’s or Duke’s are reliable choices for that rich, velvety finish.

No fresh dill? Dried dill at one-third the amount works, though the flavor won’t be as vibrant. Swap red onion for green onions if you prefer a milder bite. The celery adds crucial crunch—don’t skip it, but in a pinch, jicama or radishes can add a similar texture. For extra tang, add a splash of apple cider vinegar alongside the white vinegar.

This keeps beautifully for 4-5 days in the fridge—flavors actually improve overnight. Store in an airtight container and give it a good stir before serving. Freezing isn’t recommended; the potatoes get mushy. Perfect for picnics, but keep it chilled until ready to serve.

Step-by-Step Instructions for Costco Potato Salad

Here’s the method. Straightforward, tested, works every time.

Step 1: Cook and Cool the Yukon Gold Potatoes

Place the 2 lb Yukon Gold Potatoes in a large pot and cover with cold water by 1 inch. Add 1 tsp Granulated Sugar and 1 tsp of the Kosher Salt to the water. Bring to a boil over high heat, then reduce to a simmer and cook for 12-15 minutes until a knife slides in easily with no resistance.

Drain immediately and transfer the potatoes to a large bowl. While still hot, add the 1 tbsp White Vinegar and the remaining 0.5 tsp Kosher Salt, then toss gently. Let them cool completely at room temperature—this prevents them from turning mushy when mixed with the dressing.

Step 2: Prepare the Creamy Dressing Base

In a separate bowl, whisk together the 1.5 cups Mayonnaise, 2 tbsp Dijon Mustard, 0.5 tsp Freshly Ground Black Pepper, and 0.5 tsp Sweet Paprika until smooth. The mustard adds a subtle tang that balances the richness of the mayonnaise, while the paprika provides a hint of warmth and color.

I always use full-fat mayonnaise for this dish—it creates that signature creamy texture Costco is known for. The mixture should be thick but still pourable. Set this aside while you prep the remaining ingredients.

Step 3: Chop and Combine the Vegetables and Herbs

Finely dice the 1 cup Celery and 0.5 cup Red Onion. If the onion is particularly pungent, soak the diced pieces in cold water for 5 minutes, then drain well—this mellows the sharpness. Finely chop the 0.25 cup Fresh Dill, ensuring stems are removed for a consistent texture.

Drain the 0.25 cup Sweet Pickle Relish thoroughly to remove excess liquid, which could thin out the dressing. Add the celery, red onion, fresh dill, and relish to the cooled potatoes, then pour the dressing over the top. Fold everything together gently with a silicone spatula to avoid breaking the potato cubes.

Step 4: Incorporate the Hard-Boiled Eggs and Chill

Chop the 4 whole Hard-Boiled Eggs into small pieces. I prefer them slightly chunky for texture contrast. Fold the eggs into the potato mixture until just combined. Cover the bowl tightly with plastic wrap and refrigerate for at least 2 hours (overnight is ideal).

This chilling time allows the flavors to meld together. The potatoes will absorb some of the dressing, creating a cohesive, creamy texture. Taste and adjust seasoning if needed, though the initial measurements should provide perfect balance.

Common Mistakes When Making costco potato salad

Overcooking the Potatoes

Boil the potatoes just until tender—about 12-15 minutes. Overcooking causes them to turn mushy when mixed with dressing. Test with a knife; it should slide in easily with no resistance. 🔥

Skipping the Cooling Step

Always let potatoes cool completely before adding dressing. Hot potatoes absorb too much mayo, resulting in a gummy texture. The vinegar and salt added while warm helps prevent this issue.

Underseasoning the Dressing

Taste your dressing before combining—it should be tangy and well-balanced. The 2 tbsp Dijon mustard and 1 tbsp white vinegar are key. Adjust with Kosher salt or a pinch of sugar if needed.

Not Draining the Relish

Excess liquid from sweet pickle relish thins the dressing. Always drain it thoroughly in a fine-mesh strainer. Press with a spoon to remove all excess moisture before adding.

Rushing the Chill Time

Refrigerate for at least 2 hours—overnight is ideal. This lets flavors meld and potatoes absorb dressing evenly. Serving too soon results in a disjointed texture and taste. ❄️

Overmixing the Salad

Fold ingredients gently with a silicone spatula to avoid breaking potato cubes. Aggressive mixing turns the salad into mashed potato consistency. Keep strokes light and just until combined.

Frequently Asked Questions