DIY Carbonator Cap

The worst part of brewing is bottling.  One solution is to keg, but an equally nifty alternative is taking your aged, flat beer and carbonating it.  It can age forever at room temperature.  When you thirst for beer: decant into a PET bottle, place cap on, chill and carbonate (feel free to take on the road, no need to let settle) - beats the shit out of a growler.

A Carbonator cap is pricey, about $15 plus shipping.  I saw this DIY on a YouTube vid but couldn't find the link again and built a few from memory.  They cost about $2.50 each and seem to work swell.  Hunt down a threaded auto tire valve stem.  I got a flashy chrome one for $5 per pair at an auto parts store.  Drill a 3/8" hole in any PET cap and add an air chuck to your CO₂ tank.  Boom!  I usually put about 30-40 psi on a chilled liter of beer and it's good to go.  You should be able to get the gist from these images. (click on images to embiggen).