My first all-grain batch was, er, a bit hectic. I forgot to add my Whirlfloc tablet in the last ten minutes of the boil.

I know I can use isinglass for fining at room temperature, but my brew partner is vegetarian, so that pretty much makes me a vegetarian, too.

Can I boil up a Whirlfloc tablet with some water, let it cool, and add it to the beer when I rack to secondary?

  • What kind of beer is it? Apr 21, 2010 at 15:01
  • 1
    Cream ale. 1.045. Apr 21, 2010 at 15:52
  • I love a good cream ale.
    – brewchez
    Apr 21, 2010 at 22:14
  • Same thing happened to me on my first AG batch--a sessionable pale ale. But it cleared very well with three weeks in primary and no secondary. After force carbing and letting it sit in the keg for a few days, the sediment came out in the first pour and the beer was nearly crystal clear. I'm fairly certain that if I racked to secondary before the keg it would have been as clear as possible, all without using any finings. The grain bill was pretty light here though, so that may have helped it clear more quickly.
    – markskar
    Apr 22, 2010 at 3:28
  • I've forgotten to add irish moss before.. and it's not a big deal. RDWHAHB! :) Apr 22, 2010 at 20:34

2 Answers 2


Probably not

Irish moss (half of Whirlfloc) is a kettle coagulant. In a roiling boil the seaweed is like a snowball, crashing into and sticking to proteins. It needs that rolling action to clump. If your fermentation is still vigorous then you may get some benefit, but I'm not sure what role temperature plays.

Let it sit longer

Leave it in your fermenter for two or three extra weeks and let gravity do it's thing.

  • I'd stick with finings in the "bright tank" phase at this point.
    – brewchez
    Apr 21, 2010 at 15:47

Irish moss and whirlfloc need to be used during rolling boil, and they stick to the proteins. On the other hand, post-boil clarifiers, such as isinglass or gelatin stick to the yeast. If you use them, you should then force carbonate your beer. So it's "no" to both, i suggest you leave 2 weeks in the secondary and your beer will be clear as crystal.

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