The comfrey oil is mainly used to prepare comfrey cream and salve to help against problems of the legs, arms and skin.
The amount of roots depends on the glass that you will use for preparing the comfrey oil. Usually it is good to fill half of the glass with roots to give the oil enough space and allow the roots to expand a bit.
The oil can be every good vegetable oil. Olive oil is good for medicinal uses, because it has a strong healing effect, but other oils are good as well, especially when you don't want a strong smelling oil like olive oil.
How to do it
Fill half of the glass with the roots.
Pour the vegetable oil in the glass.
The roots should be covered completely.
Close the glass.
Fill a pan with water and heat it.
Put the glass with the comfrey oil into the pan.
Let the water in the pan boil for about fifteen minutes.
Leave the glass in the pan as long as it is warm.
Put the glass at a warm place later.
Let the glass sit at least for one night up to six weeks.
After the waiting time you need a second glass that should be bigger than the first glass.
And you need a filtering paper or cloth.
Cover the second glass with the filter.
Pour the comfrey oil through the filter.
The oil is dropping through the filter.
Sometimes this may take some hours.
When all the oil is filtered you can put the comfrey oil into a dark bottle.
Best is, if you have a small funnel.
Pour the oil through the funnel into the bottle.
Close the bottle.
Label the bottle with content and date.