Roasted Garlic Mashed Potatoes

Growing up we never roasted the garlic – we just used garlic powder. This method takes a bit longer but the garlic mellows out and gets almost sweet after roasting. The trade-off is worth it if you have the time.

June Arthurs
March 18, 2026
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Ingredients (~9 servings)

  • 3 whole heads garlic
  • 1 Tbsp olive oil
  • 3 lbs russet or yellow potatoes, peeled and cut into 2-inch chunks
  • 2 tsp fine salt (more to taste for serving)
  • 6 Tbsp unsalted butter, room temperature
  • 3/4 cup sour cream, room temperature
  • 1/3 to 3/4 cup 2% milk (start with 1/3 cup, ideally room temperature)
  • Ground black pepper (to taste)

Roast the Garlic Heads

Heat your oven to 400F.

Remove all but the innermost layer of skin from the 3 heads of garlic; slice off the top 1/4-inch or so of each head to expose the tops of the cloves.

Place each head on a sheet of aluminum foil, then drizzle the 1 Tbsp of olive oil evenly over the cut sides of all three heads to coat the surface entirely.

Wrap the cloves completely with the cut sides up in foil, then place in a baking dish or on a rimmed sheet pan.

Roast for 40-45 minutes – you’re looking for the cloves to be a deep golden brown and soft enough that they’ll squeeze out easily.

Mash the Roasted Garlic Into a Paste

Let the roasted garlic cool enough to safely handle.

Remove the cloves and place them in a bowl – you can often just squeeze them out from the bottom of each head.

Mash them up with the back of a spoon or a fork until a thick paste forms.

Boil the Potatoes

Place the 3 lbs of peeled and cut potatoes into a large pot and add enough water to completely submerge them.

Sprinkle in the 2 tsp of fine salt.

Boil for 15-20 minutes – a fork should easily insert into a large piece when they’re done.

Drain the water and then place the pot back onto the now turned-off burner for a minute or two so that any excess water in the pot evaporates.

Remove the pot from the heat.

Mash and Season

Add the roasted garlic paste, 6 Tbsp of butter, and 3/4 cup of sour cream to the pot with the potatoes.

Mash well with a potato masher as the butter melts.

Pour in 1/3 cup of the milk and stir to evenly combine.

Add the rest in smaller increments if you’d prefer a thinner consistency – I usually end up using closer to 1/2 cup total.

Season to taste with salt and pepper before serving.

The garlic flavor is mellow but it’s there – if you really love garlic, you could roast a 4th head.

Roasted Garlic Mashed Potatoes

Growing up we never roasted the garlic – we just used garlic powder. This method takes a bit longer but the garlic mellows out and gets almost sweet after roasting. The trade-off is worth it if you have the time.
prep time15 minutes
cook time55 minutes
resting or cooling time5 minutes
total time1 hour 15 minutes

Ingredients

Ingredients (~9 servings)

  • 3 whole heads garlic
  • 1 Tbsp olive oil
  • 3 lbs russet or yellow potatoes, peeled and cut into 2-inch chunks
  • 2 tsp fine salt, more to taste for serving
  • 6 Tbsp unsalted butter, room temperature
  • 3/4 cup sour cream, room temperature
  • 1/3 to 3/4 cup 2% milk, start with 1/3 cup, ideally room temperature
  • Ground black pepper, to taste

Instructions

  • Heat oven to 400F.
  • Remove outer garlic skin from 3 heads, slice off top 1/4-inch of each head.
  • Place each head on foil, drizzle with 1 Tbsp olive oil.
  • Wrap completely in foil and roast for 40-45 minutes until deep golden brown and soft.
  • Place peeled and cut potatoes in large pot, cover with water, add 2 tsp salt.
  • Boil for 15-20 minutes until fork-tender.
  • Drain potatoes and return pot to turned-off burner for 1-2 minutes to evaporate excess water.
  • Cool roasted garlic until safe to handle, squeeze cloves from heads into a bowl.
  • Mash garlic with spoon or fork until thick paste forms.
  • Add garlic paste, 6 Tbsp butter, and 3/4 cup sour cream to potatoes.
  • Mash well as butter melts.
  • Stir in 1/3 cup milk, add more in small increments if thinner consistency desired.
  • Season to taste with salt and pepper.

Notes

Garlic flavor is mellow; roast a 4th head if you prefer stronger garlic taste.