Why did this double in price? I paid $21 for the exact same product 4 months ago.

Amazon is now an authorized retailer of Dr. Hauschka Skin Care at the suggested retail price. Previously there were multiple unauthorized retailers of Dr. Hauschka products selling at a range of price on Amazon. The product authenticity, expiration date and quality could not be guaranteed. This is no longer the case. Please let us know if you have any other questions.

Where is the fragrance/parfum is derived? Is it natural or not?

Derived from natural oils. Box states "100% certified natural cosmetics - free from synthetic: fragrance, dyes and preservatives". Note: have used Dr. H products since the early 90's. Nothing on the market compares with the quality.

Do you have to wash your face after using this?

This product is meant to be used to cleanse the skin. You should either splash your face with warm water after application or you can use a warm, damp, cotton washcloth to remove the cleansing milk. Then you can spritz with toner. The cleansing cream is only meant to be used once a week. Moisturizer is meant to be used in the morning. Dr. Hauschka aestheticians recommend not using day cream at night - the oils in the cleansing milk and toner will be enough moisture as you sleep. Your skin needs a break at night to heal.