How to cut open a keg

Welcome to step 2.  I assume you have been successful in acquiring your keg(s)… well done!  Now we need to turn these things into actual brewing vessels.  The first item of business is cutting the top open.  This will allow you to use the keg for heating, mashing, or boiling.  Some people prefer to take their kegs to a welding shop to get a clean circle plasma cut, which can cost upwards of $40 per keg.  Other tutorials I’ve found recommend building elaborate “cutting rigs” to make a circular cut.  My method is extremely simple, inexpensive, and it produces the same high-quality result.  This step will require the following items:

If you don’t have all of the items laying around the house, they should be pretty easy to get.  Harbor Freight is my source for cheap tools, and they’re always running a 20% off special for the most expensive item in your order.  I have used the $12 angle grinder from Harbor Freight ($15 minus 20%) to personally cut more than 20 kegs.  Compare it to the least expensive option from Home Depot for $25.  They also offer a no-questions-asked, 90-day return policy.  The tools may not be top quality, but if they break for any reason, you can return or exchange them.  Ok, go get your supplies.  Seriously, go get them… I’ll be waiting…  …  … Got them??  Great, let’s get started!

1.  Place your 12-inch pot lid over the top of the keg, and make a mark where the outer edge is above the keg surface.

2.  Loop your string around the post on the center of the keg, and tie a knot at the sharpie mark.  Use this string as a stencil to trace a perfect 12-inch circle around the top of the keg.

3.  Take your screwdriver (or other blunt object) and depress the center ball valve on the keg to release pressure.  CAUTION – COVER KEG WITH TOWEL!  This is very important because most kegs still have some beer remaining in the bottom.  Take it from me… it will blast you directly in the face with old, stale beer if you don’t cover it.  Make sure to release all of the pressure in the keg before proceeding.

4.  Put on your safety gear!  Thumbs up for safety.  🙂

5.  Note – always use caution when operating power tools.  Serious personal injury can occur if you are careless.  Use your angle grinder with the metal cut-off wheel to trace along the circle you drew.  Take it slow, and cut 2-3 inches at a time, all the way through before moving further.  Keep the wheel moving across the metal surface while applying moderate pressure.  Don’t worry if your circle is not perfect, we will clean that up in the next step.

6.  Once your circle is cut, remove the center of the keg.  Switch to the grinding flap disc on your angle grinder.  Use this to smooth the edges of the hole, being sure to grind the bottom, inside, and top of the cut area.  Feel with your glove to make sure that no sharp edges remain.  Take your pot lid, and check it for fit.  If the hole is too small, continue to grind the edges of the hole until the lid fits.

Congrats!  You should now have a 12-inch, smooth-cut hole in the top of your keg.  You just saved up to $40 per keg by doing this yourself!  Pat yourself on the back, grab a brew, and come back for Step 3.