How to Cook Costco Ham

The Kirkland Signature Spiral Sliced Ham is one of Costco’s most popular holiday items. It shows up in stores around Thanksgiving, Christmas, and Easter.

This bone-in ham comes fully cooked and pre-sliced in a spiral pattern. A glaze packet is included.

You’re basically just reheating it. But do it wrong, and you’ll end up with dry, tough meat.

This guide covers three cooking methods with exact temperatures and times. The oven method takes about 2 hours. The slow cooker needs 3-4 hours but frees up your oven. Reheating individual slices in the microwave takes just minutes.

Product Details

Product: Kirkland Signature Spiral Sliced Ham, Hickory Smoked

Type: Fully cooked, pre-sliced, bone-in

Package Size: 9-10 lbs average (feeds 14-16 people)

Price: $2.29-$2.49 per pound at Costco (Updated December 2024)

Storage: Keep refrigerated

Calories per Serving: 100-140 calories (3 oz serving)

Main Ingredients: Pork, water, sugar, salt, sodium phosphate, sodium erythorbate, sodium nitrite

Item Number: 26159

Cooking Methods Comparison

Recommended Method: Oven for caramelized glaze and traditional presentation

Method 1: Oven (Recommended)

This is the classic approach. Takes about 2 hours for a 9-10 pound ham. You get that beautiful caramelized glaze with slightly crispy edges.

The slow, low heat keeps the meat moist. Rushing it at higher temps dries out the slices.

Step 1: How Do You Prepare the Ham?

Remove all packaging, including the plastic disc covering the bone. Let the ham sit at room temperature for 30 minutes before cooking. This helps it heat more evenly.

Instructions:

1. Unwrap the ham and discard all plastic packaging
2. Place flat-side down in a shallow roasting pan
3. Add 1/2 cup water, apple juice, or pineapple juice to the pan bottom

Equipment: Roasting pan, heavy-duty aluminum foil, meat thermometer

Step 2: What Temperature and Time Do You Use?

Low and slow is the key. The package says 275 degrees F for 12-15 minutes per pound. That’s about 2 hours for a typical 9-pound ham.

Some folks prefer 325 degrees F for 10-12 minutes per pound. Works fine, just watch it more closely.

Instructions:

1. Preheat oven to 275 degrees F
2. Cover ham tightly with aluminum foil
3. Bake for 12-15 minutes per pound (about 2 hours total)

Temperature: 275 degrees F

Time: 12-15 minutes per pound

Step 3: When Do You Add the Glaze?

Save the glaze for the end. Adding it too early just burns the sugar.

Mix the glaze packet with 3 tablespoons of water. Heat it until it bubbles, either on the stove or 60-90 seconds in the microwave.

Instructions:

1. Remove ham from oven when internal temp reaches 130-135 degrees F
2. Pour off excess liquid from pan
3. Brush glaze over the ham and between the slices
4. Increase oven temperature to 425 degrees F
5. Return ham uncovered for 8-10 minutes

Checkpoint: Internal temp 130-135 degrees F before glazing

Step 4: How Do You Know When It’s Done?

The ham is fully cooked when you buy it. You’re just heating it through and adding that sticky glaze.

Use a meat thermometer. Insert it into the thickest part, not touching the bone.

Instructions:

1. Check internal temperature reaches 140 degrees F
2. Glaze should be bubbling and slightly caramelized
3. Let ham rest covered for 10-15 minutes before carving

Target Temperature: 140 degrees F

Visual Indicator: Golden brown glaze with bubbling edges

Method 2: Slow Cooker

The crockpot method is a lifesaver during the holidays. Set it up in the morning and forget about it. Your oven stays free for everything else.

The ham comes out incredibly tender. Almost falling-off-the-bone tender. Took me a while to realize this was actually the easier way to go.

One catch: Most slow cookers only fit a 7-8 pound ham. You might need to trim yours to make it fit.

Step 1: How Do You Prepare the Ham?

Spray the slow cooker with nonstick cooking spray. This makes cleanup way easier.

Instructions:

1. Remove packaging and discard the included glaze packet (we’ll make a better one)
2. Place ham flat-side down in a 6-7 quart slow cooker
3. If the lid won’t close, trim the bottom of the ham or cover with foil instead

Equipment: 6-7 quart slow cooker, meat thermometer

Step 2: What Temperature and Time Do You Use?

Low heat is the only way here. High heat dries out spiral ham every time.

Instructions:

1. Rub 1 cup brown sugar over the ham
2. Pour 1/2 cup maple syrup and 1/2 cup pineapple juice over the top
3. Cover and cook on LOW for 3-4 hours

Temperature: LOW setting only

Time: 3-4 hours

Step 3: When Do You Baste?

Basting helps distribute the glaze flavors. Do it a few times during the last hour.

Instructions:

1. At the 2-hour mark, spoon juices from the bottom over the ham
2. Baste again at the 3-hour mark

Checkpoint: Baste at least twice during cooking

Step 4: How Do You Know When It’s Done?

Instructions:

1. Insert meat thermometer into thickest part
2. Temperature should read 140 degrees F
3. Transfer to serving platter and let rest 5-10 minutes

Target Temperature: 140 degrees F

Visual Indicator: Ham is steaming and glaze has thickened

Optional: For a caramelized finish, transfer ham to a baking sheet and broil for 3-5 minutes after slow cooking.

Method 3: Microwave (Reheating Slices)

This works for leftover ham slices or when you just want a quick serving. Not ideal for the whole ham, obviously.

The microwave won’t give you that crispy glaze. But it’s fast and gets the job done for weeknight dinners or sandwiches.

Step 1: How Do You Prepare the Slices?

Instructions:

1. Arrange ham slices in a single layer on a microwave-safe plate
2. Add 1-2 tablespoons of water or broth to keep meat moist
3. Cover loosely with a damp paper towel

Equipment: Microwave-safe plate, paper towel

Step 2: What Power Level and Time Do You Use?

Instructions:

1. Microwave on HIGH for 1-2 minutes
2. Check and rotate slices halfway through
3. Add 30 seconds if not steaming hot

Power Level: HIGH (100%)

Time: 1-2 minutes for 3-4 slices

Step 3: How Do You Know When It’s Done?

Instructions:

1. Slices should be steaming hot throughout
2. Touch test: center of slice should be hot, not just warm

Target Temperature: 165 degrees F for reheated ham

Visual Indicator: Steam rising from slices

Safety and Quality Indicators

Food Safety

• Internal Temperature: 140 degrees F minimum (ham is pre-cooked)
• Steam Check: Product should steam when cut open
• Thawing: Never needed, this ham is sold refrigerated, not frozen

Quality Indicators (Done Properly)

• Color: Pink interior with golden-brown glazed exterior
• Texture: Tender and juicy, not dry or rubbery
• Temperature: Hot throughout (140 degrees F or higher)
• Appearance: Caramelized glaze with slight crispy edges

Signs of Overcooking

• Dry, stringy texture on outer slices
• Edges turning dark brown or black
• Meat pulling away from the bone excessively

Serving Suggestions

Portion Size: 3/4 to 1 pound per person (bone-in ham has less edible meat)

Serving Ideas:

• Classic holiday dinner with Costco mashed potatoes and roasted asparagus
• Ham sandwiches on King’s Hawaiian rolls with Dijon mustard
• Diced ham in scrambled eggs or omelets for breakfast

Pairing Recommendations:

• Scalloped potatoes or Costco mac and cheese
• Roasted green beans, glazed carrots, or Brussels sprouts
• Fresh dinner rolls or Costco garlic bread
• Apple cider, sparkling wine, or iced tea

Storage and Reheating

Leftover Storage

• Refrigerate within 2 hours of cooking
• Store in airtight container or wrapped tightly in foil
• Consume within 3-5 days
• Freeze for up to 2-3 months in freezer-safe bags

Reheating Instructions

• Microwave: 1-2 minutes on HIGH, covered with damp paper towel
• Oven: 275 degrees F for 10 minutes, wrapped in foil
• Stovetop: 2-3 minutes in skillet with splash of water or butter
• Target Temperature: 165 degrees F for reheated leftovers

Troubleshooting Common Issues

Issue: Ham is dry around the edges

Cause: Overcooked or not covered properly with foil

Solution: Cover tightly with foil. Check temperature earlier. Remove from oven at 135 degrees F and let carryover cooking finish it.

Issue: Center is still cold

Cause: Ham too cold when it went in, or oven temperature too high

Solution: Let ham sit at room temperature 30 minutes before cooking. Use lower temperature (275 degrees F) for more even heating.

Issue: Glaze burns before ham is heated through

Cause: Glaze applied too early in cooking process

Solution: Only add glaze during the last 10-15 minutes. Remove foil, brush on glaze, then increase oven temp to 425 degrees F.

Issue: Ham doesn’t fit in slow cooker

Cause: Costco hams run 9-10 pounds, larger than most crockpots handle

Solution: Trim the bottom of the ham until it fits. Put trimmed pieces alongside the main ham. Or cover with foil instead of the lid.

Product Variations and Related Items

Similar Costco Products

• Kirkland Master Carve Applewood Smoked Ham – Boneless, smaller (3-5 lbs), $3.99/lb. Easier to carve, takes less time to cook.
• Costco Turkey Breast – Alternative protein for holiday dinners. Different cooking times apply.
• Costco Pork Loin – Fresh option if you want to cook from scratch.

Cooking Time Adjustments

For the Master Carve boneless ham: Cook at 400 degrees F for 15 minutes per pound. Target internal temperature of 130 degrees F.

For smaller spiral hams (7-8 lbs): Reduce total oven time by 20-30 minutes. Check internal temperature starting at 90 minutes.

Which Method Should You Choose?

Choose Oven when:

• You want that classic caramelized glaze
• Presentation matters (holiday dinners)
• You have 2+ hours available

Choose Slow Cooker when:

• Your oven is full with other dishes
• You want hands-off cooking
• Tenderness is more important than crispy edges

Choose Microwave when:

• Reheating individual servings
• Making ham sandwiches or breakfast
• Speed is the priority

Time Comparison

Microwave (1-2 min) < Slow Cooker (3-4 hours) < Oven (2-2.5 hours)

Wait, that looks backwards. Let me explain. The slow cooker takes more wall-clock time, but less active effort. The oven is faster overall but needs more attention.

Texture Comparison

Slow Cooker (most tender) > Oven (best glaze) > Microwave (convenience only)

The hickory smoked flavor comes through with any method. The main difference is how the glaze caramelizes and how tender the outer slices get.

What to Make with Leftover Ham

That 9-pound ham produces a lot of leftovers. Here are some ideas beyond sandwiches:

• Ham and split pea soup (the bone makes amazing stock)
• Ham fried rice with Costco frozen vegetables
• Ham and cheese quiche or frittata
• Diced ham in breakfast burritos
• Ham salad for sandwiches or crackers

The ham bone is worth keeping. Freeze it if you’re not making soup right away. It adds incredible flavor to bean dishes and stocks.

FAQ on How To Cook Costco Ham

How long do you cook a Costco spiral ham?

Cook the Kirkland Signature spiral ham at 275 degrees F for 12-15 minutes per pound. A typical 9-pound ham takes about 2 hours.

Add 8-10 more minutes at 425 degrees F after brushing on the glaze.

What temperature should I set my oven to?

Preheat your oven to 275 degrees F for slow, even heating. This keeps the precooked ham moist.

Increase to 425 degrees F only at the end to caramelize the brown sugar glaze.

Do I need to thaw the ham first?

No thawing needed. Costco sells this hickory smoked ham refrigerated, not frozen.

Just let it sit at room temperature for 30 minutes before cooking. This helps it heat more evenly throughout.

How do I keep the spiral sliced ham from drying out?

Cover tightly with aluminum foil during cooking. Add 1/2 cup of water, apple cider, or pineapple juice to the roasting pan.

The liquid creates steam that keeps the bone-in ham juicy.

Can you eat Costco ham without cooking it?

Yes. The Kirkland spiral ham is fully cooked and safe to eat cold straight from the package.

Most people prefer it warmed to an internal temperature of 140 degrees F for better flavor and texture.

How do I make the glaze that comes with the ham?

Mix the glaze packet with 3 tablespoons of water. Heat on stovetop until it boils, or microwave for 60-90 seconds.

Brush between the spiral slices for maximum flavor. The glaze is mostly sugar.

How many people does a Costco ham feed?

A 9-10 pound ham feeds 14-16 people. Plan for 3/4 to 1 pound per person since bone-in ham has less edible meat.

You’ll likely have plenty of leftovers for sandwiches.

Can I cook the ham in a slow cooker instead?

Absolutely. Place the ham flat-side down in a 6-7 quart crockpot. Add brown sugar, maple syrup, and pineapple juice.

Cook on LOW for 3-4 hours until the meat thermometer reads 140 degrees F.

How long can I store leftover ham?

Refrigerate leftover ham in an airtight container within 2 hours. It stays fresh for 3-5 days.

For longer storage, freeze slices in freezer bags for up to 2-3 months.

What side dishes go well with Costco ham?

Classic pairings include scalloped potatoes, roasted asparagus, and glazed carrots. Dinner rolls are a must.

Try serving with Costco potatoes or green bean casserole for a complete holiday dinner.

Conclusion

Learning how to cook Costco ham takes all the stress out of holiday dinners. The Kirkland Signature spiral ham does most of the work for you.

Whether you choose the oven for crispy caramelized edges or the crockpot for tender, fall-off-the-bone meat, you’ll get great results.

Remember the basics: 275 degrees F, 12-15 minutes per pound, and always use a meat thermometer. Let it rest before carving.

Save that ham bone for split pea soup. Your Easter or Christmas dinner guests will be impressed, and you’ll have leftovers for days.