52839
A hopback is a traditional additional chamber that acts as a sieve or filter by using whole hops to clear debris ( or " trub " ) from the unfermented ( or " green " ) wort , as the whirlpool does , and also to increase hop aroma in the finished beer .
 hops, wort
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 hops, wort