Force carbonation occurs in the keg, not the bottles.
Carbonation wrt to the article, occurs in the keg using a CO2 tank. Once the beer is carbonated, it is transferred to the bottles via a counter pressure filler.
For this process you will need:
- CO2 Tank
- Regulator (CO2)
- Lines and Connections (including a tee for gas line)
- Counter Pressure Filler (I personally use this one, there is a version with a gauge, that is IMHO unnecessary, there are brass/copper ones as well, but these can impact your final product)
- Bottles (which you obviously already have)
- No. 2 Stopper - suitable for most bottles
The process is as follows:
- Purge system with CO2
- Transfer beer from fermentation vessel to keg (filter if desired)
- Connect CO2 to Keg (a variety of methods exist, it comes down to a balance between time and volatilization of aromatics)
- Once carbonated, connect counter pressure filler
- Purge bottle with CO2 (combination of burping and allowing flow through pressure release valve (PRV))
- Rapidly switch valve to open beer line (rapidly is key, learned after painting my kitchen in beer)
- Bottle should slowly fill with no foam, once beer pours out PRV, close valve remove counter pressure filler and cap. (You can fob with CO2 if you have extra hands to prevent oxygen pickup for longer shelf life)
- Sanitation is as always important! Ensure all things that touch beer are sanitized.
- Cold is better! If you can chill your bottles you will lose less beer to foaming. Additionally, your keg should be cold, and if you'll be taking a while to transfer, insulate it to keep it cold.
- Some bottles can be sterilized. Perform with caution ideally run a test on a couple of bottles first, as some cannot tolerate the heat. You can sterilize your bottles by capping them with tin foil, and baking them in the oven (once cleaned). Start with the oven cold, gradually raise the temperature. 65 C for 5 minutes is sufficient to provide sterilization. Gradually cool the bottles thereafter. They will remain sterile for all intents and purposes so long as the foil remains tight.