You know me, I like my beer fresh. It's tastier that way. Luckily I own a brewery and have 24/7 access to as much of the stuff as I could drink in a lifetime. That's me sorted then, but what about you? I want you too to enjoy the daily experience of bright, gorgeous flavours. But you don't work here, so how do I get it to you without it turning old, oxidised and stale?
Well, if we keep live yeast in the beer it will keep it in good nick for a few weeks, so long as we exclude oxygen from every part of the process (saving, of course, at the very beginning of fermentation when the yeast uses the stuff the create sterols for growth). Oxygen, you see, is my arch enemy: it forms the precursors to staling and thus shortens the time I have available to get my lovely fresh ale to you, for you to enjoy.
Keep yeast in, keep oxygen out. That's about it. Oh, except keeping the light out. Well, certain wavelengths of light. But that's another story and not strictly relevant to this discussion. So, no oxygen, plenty of lovely yeast. That's pretty much all. And I can rely on packaging to provide these. Doesn't matter what packaging, so long as it does the business.
As it happens, for economic reasons, I use stainless steel casks. They can be cleaned and sterilised with ease, filled quickly, sealed up and rolled down the road to the pub, where the landlord recognises the format and knows how to get the beer out. Great.
There are other options available. There are kegs. These are no different to casks, within our terms of reference as explained above. They keep oxygen out and let me include yeast with my beer.
But, for some reason, they have the added, and unusual, ability to make people angry.
I don't understand.
Can anyone explain?