It ir really worth using Irish moss when boiling the wort? Does it affect the taste in any way?
Yes it is worth using it and no it does not affect the flavor.
With over a hundred years of practice, I’d say that its a proven clarifier. If you prefer clearer beer, use it. It can’t fix all faults though.
I like using Whirlfloc tablets which are a refined type of Irish Moss and can be tossed in 15 minutes before the end of the boil.
As Martin states they are not a panacea but are quite effective and very easy to use.
I will be bottling the first brew I have ever tried Whirfloc tablets in tomorrow. I will know in a few weeks what I think of it.
I’ve skipped using Irish moss once and ended up with a cloudy bitter. That was also my first, and only, use of gelatin to try to drop some haze. But I do often cut back on the amount of IM and it still seems to work.
Manufacturer recommends 5 m in. before the end of boil. One tab is good for 12 gal., so 1/2 tab is fine for a 5 gal. batch. There’s a lot of confusion about this because so many retailers repackage Whirlfloc with inaccurate instructions.
Good to know though they take longer than 5 minutes to dissolve.
Now you tell me. I did mine at 15 minutes. Will they still work?
They still work.
I always throw it in at 15 and it seems to work fine
I always forget the Irish moss. Always.
Time seems to work to clarify my beers.
When I need it clear quicker, I toss in some gelatin.
The ones I get seem to dissolve in a few seconds.
Whirfloc rocks. I toss mine in at 10 minutes with my IC and yeast nutrient.
Dave
Mine fizz and take about ten minutes to dissolve.
euge, are you sure that’s whirlfloc and not alkaseltzer? 
I doubt it really makes a difference, but Kerry’s packaging recommends 10 min for Whirlfloc T and 15-20 min for Whirlfloc BWS. http://crosby-baker.com/index.php/processing-aids/kettle-coagulants.html
The BWS is horrible stuff to work with, BTW. Well worth the small premium for the tablets.
Wow, you must have some tough Whirfloc! When I add 1/2 tab it dissolves almost instantly.
Might very well work fine, but the company line is that it starts to denature and become less effective after 5 min.
Thanks, Sean!