Have the cream at 60 degrees F. Pour into an 8-quart glass churn and turn the paddle. Do not turn it too quickly. After a while, small balls of butter will begin to form and float in the cream. Soon after that a large chunk will form and all that will be left is the buttermilk. Pour off the buttermilk and pour in some ice cold water and "rinse" the butter. Pour out the water. Season with salt, to taste. Store in a re-sealable container in the refrigerator.