The method in this video is one every brewery, cidery and kombucha maker can use.
The problem with cleaning stones in the tank
It’s normal to put carbonation stones in a tank while you run your caustic rinse. But that only cleans the surface. You’ll get most of the beer stain off, sure, but the pores inside the stone stay plugged. Plugged pores mean big bubbles, and big bubbles don’t carbonate your beer.
One safety note if you do clean in-tank: caustic reacts with CO2, and in a tank still full of CO2 it can pull a vacuum strong enough to collapse the vessel. Vent the tank or make sure its vacuum relief valve is working first (Paul Mueller).
The fix: force caustic through the stone
Our method uses the Torpedo: a 1.5-inch straight tube with Dixon sanitary push-to-connects and tri-clamp fittings, which uses CO2 to force caustic through the stone:
- Set up on a table. Pull the push-to-connect off the top of the tube and fill it with caustic cleaner. Wear safety glasses and gloves.
- Attach the dirty stone to the bottom connection. As a bonus, this also flushes and cleans your ball valve and check valve at the same time.
- Connect your CO2 line with a needle valve to control the flow.
- Turn on the CO2 and push the caustic all the way through the stone. Repeat until what comes out runs clean.
- Check the result: put the stone in a bucket of water and run CO2 through it at the same pressure as before cleaning. A clean stone passes far more gas.
A badly fouled stone ran at about 15 PSI with a maximum of 5 cubic feet per hour through it. Three caustic flushes later, the flow difference was dramatic, because all the pores were open again.
Handling and other cleaning options
Whatever method you use, avoid touching the stone with bare hands, because skin oils can plug the pores. Don’t brush a sintered stainless steel stone (GW Kent). For the deepest clean, use an ultrasonic bath: BrewWizz’s Ultrasonic Stone Cleaner is its recommended method for ceramic stones, and GW Kent names ultrasound as the best way to clean stainless ones. The brush supplied with the WizzStone-Combo is for its ceramic diffuser.
Why this matters for carbonation quality
Open pores give you lots of tiny bubbles. Tiny bubbles dissolve instead of racing to the headspace. Our guide to the physics of bubble size explains why.
Want better control over your carbonation? Contact us today. The Torpedo and Ultrasonic Stone Cleaner are available at brewwizz.com.