Cover the bowl or top
part of the double boiler and keep the water at medium / high temperature for at least 30 minutes or until oil has adopted a darker color and smells strongly of rosemary.
Bring water in the bottom
part of a double boiler to an easy boil or simmer.
Remove the top
part of the double boiler carefully, as it will be hot.
Fill the lower
part of the double boiler with 1 - 2 inches of water and place over high heat.