Often a bentonite and casein blend (Bentolact S) is a fast and easy way to reduce bitterness. If you have already protein stabilized with bentonite, try adding a small amount
(25 ppm) of the Scott'Tan FT Blanc Soft to eliminate the bitterness. The Bentolact S will precipitate the bitter molecules while the tannin will mask bitterness. Bench trials
are recommended.