I've never used whirlfloc or irish moss. I've used gelatin every time and love the results. There's so much info now that contradicts the old philosophy of leaving trub in the kettle. I throw everything in the fermenter, let it ferment out, start the cold crash to about 48-50*F, add gelatin and continue crashing to 38*F. I love the result I get from gelatin
I think the technical reason for wanting to use both is that they target different material and really aren't a substitute for one another in that regard:
-- Whirfloc (Irish Moss) is used to precipitate "break" material, IOW trub produced during the boil and subsequent cool down with the goal of producing as clear of wort as possible and minimize trub transfer to the fermenter.
-- Gelatin (fining agent) is primarily used post fermentation to flocculate yeast and proteins that you want to settle out of the final beer.
I've never used whirlfloc or irish moss. I've used gelatin every time and love the results. There's so much info now that contradicts the old philosophy of leaving trub in the kettle. I throw everything in the fermenter, let it ferment out, start the cold crash to about 48-50*F, add gelatin and continue crashing to 38*F. I love the result I get from gelatin
I never used gelatin, just in case I serve beer to a vegetarian friend or someone not expecting meat products in a beer.
However, I use whirlfloc in the kettle (when I remember, which is most of the time), and my beer is so clear you can read a newspaper through it.
-- Whirfloc (Irish Moss) is used to precipitate "break" material, IOW trub produced during the boil and subsequent cool down with the goal of producing as clear of wort as possible and minimize trub transfer to the fermenter.