Pubs / Breweries pouring beer down the drain?

[SWnewstart]

It's been mentioned before during lockdown and has just been on our local news - pics of metal barrels (kegs?) of beer being poured down drains. Why? Does beer / lager have a very short shelf life? It simply don't get why it is not OK to keep and sell in a few weeks or months time. What facts am I missing?

Because keg beer has live yeast in it. Gassed beer keeps better.

Once tapped (opened), the beer needs to be drunk fairly quickly.
And, yes, it does go off, even if not opened.

Cask ale (real ale) lasts 3 days once open. From memory lager/keg ale is 7 days and cider 2 weeks. Also think, the beer travels in pipes ("lines") up to the bar. Would you want to drink the pint that's been sitting in the pines for weeks? Bleugh

Well I had no idea beer /ale "went off" so quickly, thanks for the explanatory responses. I'm sure when I was younger and around village pubs (mid 70s) wooden barrels of beer wouldn't have been wasted like this. I guess brewing methods have changed!

The wood barrels are casks and they 100% would have been binned if not sold in 3 days, even in the 70s. The landlord would make sure they sold though, if a beer was on the third day they'd probably take one or more of the other beers off until the dodgy one sold.

Have you ever worked in a pub OP or just drank in them? A fair amount goes on behind the scenes. Every week a few gallons gets chucked when the lines are cleaned. It's just built in to the price of the pint.

I'm sure in the 70s the pubs wouldnt be forced to shut for a month (or longer)!

It makes my blood boil. It's a fucking disgrace what's happening to our hospitality industry.

Keg beer goes bad very quickly, hops also fade and it stops tasting of anything

Again thanks everyone for the info. No, Smeerf, I've never worked behind a bar or I'd have a better idea of how it all works with beer "going off". I guess I have to Google beer / wine making processes as, in my mind, they are kind of similar i.e. hops / grapes fermenting but wine then last for ages! I obviously have a lot to learn