Wash and peel the potatoes.
Put the potatoes in a large pot.
Add enough water to cover the potatoes by about an inch. (Do not fill the pot more than 2/3 full or it may boil over more easily)
Place pot (with potatoes and water) on the stove and bring to high heat.
Allow to come to a boil for about 15 minutes.
Check the potatoes occasionally with a fork. (If potatoes are soft and can be easily punctured with a fork, they are done).
Using a strainer, drain the water from the potatoes.
Return potatoes to the pot.
Use a potato masher to mash potatoes until smooth.
Add butter to the mashed potatoes and stir until melted.
Add milk to potatoes.
Add sour cream to potatoes.
Add salt and pepper to potatoes.
Stir and mash again until you reach desired consistency.
Add more salt and pepper as desired.
