This is my first recipe I created on my own using my home-grown hops. It smells amazing! Crisp and fresh beer. Definitely one of my favorites. I recommend 2-3 weeks fermentation. Crystal is actually 20L not 15L but that option was not listed. Note that the hop leafs I used were from a harvest 1.5 years ago so your IBUs and use of hops may be lower and IBU should be lower that what is actually listed.