На първо четене в гугъл е това:
https://longweekendbrewing.wordpress.com/2015/10/10/pure-hop-aroma-all-the-aroma-none-of-the-hop-matter/Пише, че е естествен продукт. Използва се вместо сухо охмеляване 24ч преди бутилиране или в кега преди газиране. Добавя само
аромат, не и вкус. Не се вари или слага преди ферментацията, защото изветрява с варенето или с отделянето на CO2.
Ето и мнението на домашен пивовар. Взех го от някакъв форум:
"I have been testing the oils for a while now and have also been given a fair bit of feedback from samples that were sent to various homebrewers for their honest opinion.
If the oils are used as directed they work really well. It is the first time I have been able to recreate that dry hop aroma, like putting your nose in a bag of goldings type aroma, in my beer. Just like a pint of casked Bombadier I had in a really well managed "spit and sawdust" pub.
As Ale man has pointed out these oils have nothing to do with bittering at all. From the feedback I have received I have seen that people want to use them for flavour, used at that strength they can start to taste chemically, but you have to really over do it.
I have also been impressed by the staying power. Hop aroma does not really last in a cornie for long but the oils do, in my experience.
They may not be the the complete answer for every brew but certainly have their place, they have improved my beer.
As always I am interested in any feedback, good and especially bad.
Cheers"
http://www.thehomebrewforum.co.uk/showthread.php?s=920c461c2774d896e82defebc7fec118&t=12748&page=2