The Oil Drum

You're right, homebrewing is easy. If you can make spagetti (and wash the dishes) you can brew beer.

That said, in a post peak world where beer is not readily available, so too are the ingredients that make hombrewing so easy hard to get.

So if you can't buy beer, you can't buy liquid malt extract and pellet hops. What to do?

Okay, growing hops is easy, they're a weed.

Then you have to grow barley. Tough enough. Next you have to malt. Not so easy. Kiln it if you want something other than a light ale. Mash it etc.

Also where are you going to get your yeast? if beer isn't available so isn't yeast. You have to learn to wash and propagate your yeast.

You can make beer, but its not easy (some would say the complexity of making beer led to civilization).
Cider, wine and mead are all much easier.

Case in point, colonial america. Beer was much to difficult and resourse intensive to make. Early American's drank cider and rum (from imported molases). Both are much easier than beer.

I've got 18 liters of wheat beer (wort) sitting on my stove with the immersion chiller. In about another 10 minutes it'll be cool enough to pitch the yeast.
I've also go 1.2 liters of cherry ale in me. It's a holiday here in Japan, the wife is at work, the sun is shining, and I'm living a sweet sweet moment in life.
Sometimes its almost enough to make you forget about peak oil :-)