Universal Carboy Cap


This Carboy Cap fits 3, 5, and 6 gallon carboys (does not fit 6.5 gallon carboys). It fits tightly around the carboy mouth, and the two openings are convenient for attaching or inserting tubes, airlocks, siphons, or racking canes. Caps for both openings are included.

The beauty of this item is its flexibility and usefulness in combination with other equipment. See our recommendations below, or engineer your own!


  • BPA Free

Starting a Siphon...

Put your racking cane into the middle hole of the cap. Then, to start the siphon, blow into the other hole. Air pressure on the liquid will force it up the racking cane, thus starting your siphon!

Capturing Yeast or Fermentation Overflow...

Want to avoid spills from a vigorous fermentation or collect top-fermenting yeast for re-use in another batch? Insert a racking cane into your carboy through the center hole of your Carboy Cap, keeping the other hole closed. Cap a small overflow vessel (like a 3 gallon carboy) and run a tube from the racking cane into the side hole on of the cap on the smaller container. Insert your airlock into the center hole of the overflow vessel's cap.

As you can see it is very versatile.

Note: we do not sell our products directly.

If your local retailer does not carry our products, feel free to e-mail us so we can direct you to the nearest retailer.
If you are a retailer, please let your preferred wholesaler know about your needs.