Basic question from a new brewer

Hi everyone.

I have a basic doubt with the gas i put in my beer.

I have only done beer from begginers malt extract. As I understood the gas come from the sugar i put in the beer right before bottling. Its simple and makes sense.

If i want to serve from draft (from a keg) how will I put gas into it? Sugar isn't an option here right?

Thanks and i hope someday i'll help you too!

The gas is CO2, carbon dioxide, it's given off by yeast as they eat the sugar (they're farting). The CO2 they give off, if trapped in a bottle, will eventually go back into the beer, giving it carbonation.

With kegs, you can use sugar, but you'll be using less sugar than you would if you were bottling.

Most people who use kegs don't use sugar, they buy a CO2 tank and get it filled with CO2 - they force the CO2 into the beer to carbonate it. It can be done quickly, in as little as a few days, but the proper way to do it takes about 2 weeks, which is about how long bottling takes

I see, many thanks!

So if you shake the barrel for 2 hours you carbonate the beer faster, right?

Yes, though it's not recommended

https://www.homebrewtalk.com/f35/keg-force-carbing-methods-illustrated-73328/

If you keg, you HAVE to have a Co2 bottle.
You can carbonate your beer in the keg with sugar just like a bottle (With less sugar, though, as was pointed out)

But, as you serve your now carbonated beer, it'll go flat because you're essentially using your carbonation to push the beer out of the keg instead of keeping it in the beer.

And, once you have a Co2 tank, why not just force carbonate and skip the sugar (Rhetorical question, there are valid arguments both ways)