Irish moss vs bentonite for clearing beer

[Beginnier927]

I know I've been throwing a lot of threads lately, but I'm new to this hobby (I know it's a profession, I call it a hobby cause I'm not a pro) and I'm so excited about it.

I can get my hands on bentonite and Irish moss at twice the price of the bentonite, I've heard so much about Irish moss, but I didn't know how it works, apparently, you rehydrate that stuff and then you mix it with the wort at the last 15 minutes of the boil? what's the point of using Irish moss before fermentation? Doesn't fermentation make the cleared beer unclear again?
And how about bentonite? Can it be used to clarify beer? I guess it needs to be used post fermentation

Will these fining agents make bottle conditioning and carbonation impossible?

 

[Protos]

They are used for slightly different purposes.

Irish Moss which you add to the boiling wort helps to clump together and precipitate protein particles in the wort. This is important if you want to harvest and reuse your yeast: the more protein particles you leave out of fermenter the purer yeast slurry you'll have.

Post-fermentation you want to clear you beer not as much of protein particles as of suspended yeast cells. Here Bentonite comes to help, although in brewing it's more common to use Gelatin rather than Bentonite for this purpose.

 

[DBhomebrew]

A typical ale with a typical process and timeline will have enough yeast cells for bottle conditioning even with the use of finings.
Bentonite is used in mead a lot with the suggestion of adding the bentonite at pitch. The natural agitation of fermentation will help the bentonite service the full volume.

 

[BeerHolic]

Locally for me gelatin and bentonite is very similarly priced.
Gelatin is more readily available.
Bentonite is a good vegan alternative as gelatin is made from animal collagen.

 

[tld6008]

Gelatin works good but you have to be able to chill the beer after adding it.