Diffusion Stone (0.5 micron) Fermentap

The primary use for this extremely fine diffusion stone is to force carbonate beverages with carbon dioxide or to oxygenate wort using an oxygen regulator. The holes in the stone are too fine to use it to aerate the wort with an aeration pump. However, compared with the 2.0 micron stone, the 0.5 micron stone will carbonate beer quicker and with a longer lasting head because the bubbles that it creates are smaller. The stone is 1″ long and .5″ in diameter.

Force carbonating beverages.
To use a diffusion stone to force carbonate beer, champagne, or sparkling meads, you will need a homebrew kegging outfit with CO2 tank, regulator, lines, and a keg. Simply attach a 24″ length of 1/4″ ID tubing to the gas side dip tube of your keg with a worm clamp. On the other end of the tubing, attach the diffusion stone. A worm clamp here is your choice. There are charts available online and in books for exact levels of temperature and CO2 pressure to achieve desired carbonation levels. Following is an example for average carbonation in beer. Chill the beer to 40 F. Adjust the regulator to 2 PSI and attach the gas disconnect. Every 3 minutes increase the pressure 2 PSI until 12 PSI is reached. At this point the beer will be carbonated, but it won’t hurt to leave it alone in the refrigerator for a few days under pressure.

If using pure oxygen to oxygenate the wort, about 40 seconds are required. Try it in two 20 second bursts: one before pitching yeast, and another 3 hours after pitching. High gravity beers may require more time because oxygen does not dissolve as easily in liquids with a high specific gravity.

Never touch the diffusion stone. Use sanitized gloves. Oils from your fingers will clog the holes.