Not 'followed' per se, Guinness was pretty late to that shift, the vast, vast majority of commercial beer is fined using other methods.
You'll only see it in beers that hold to 'traditional' methods as part of their cultural schitck, for example I think its still pretty common in "real ale" and beers that undergo cask conditioning. In other words, those beers you get a traditional pubs out of the hand crank served somewhat warm and flattish.
Isinglass (dry swim bladder protein) was used as a fining agent.
You can do the same with gelatin, but isinglass had the helpful point that it was a waste product from nearby fish processing, and doesn't require all the cooking and processing required to make regular food-grade gelatin.
Basically, any little floaty bits (yeast, grain mash, etc) stick together when you add fining agents to your beer, wine, cider or any fermented alcohol, and they're heavy so they sink out, making the beer clear and the mouth-feel & taste less muddy.
I've actually got some fining in my fridge right now, I'll see if I can get a good picture.
Edit: don't know if this'll come out well through reddit's hosting, but the bottle is cloudy cos it's cold, and its warm and humid here today. Instant frostiness. Otherwise, the liquid is clear, and all the sediment from brewing is formed into a loose lump at the bottom there with a very small amount of gelatin added.
4
u/narwaffles 6h ago
Does guinness still have fish guts or is that only the old recipe too?