Pour heavy cream into your blender and blend on high. You'll want to shut it off periodically to scrap down the sides and mix it up a little.

Continue blending until finally the heavy cream begins to separate, about 4-5 minutes.

You'll see the beginnings of butter and buttermilk, make sure to stir up and continue blending for another 30 seconds or so.

Remove the lid and pour the buttermilk out into a separate container if you're going to keep it, or down the sink if you just want to discard it.

Add salt to taste.

Blend butter and drain twice more.

Once you've drained as much of the milk as you can, scoop the butter out onto a folded 12 x 12 square of cheese cloth.

Bring the edges of the cheese cloth together over the butter and squeeze the butter out with your hands.

Now run the butter under cold water and continue to squeeze. This will allow the butter to last longer.

Remove from cheese cloth and store in an air tight container for up to three weeks. Do the same thing for the buttermilk if you're saving that too.