Other Uses for Cornelius Kegs

Other Uses for Cornelius Kegs
           Sometime ago I obtained a few Cornelius (Corny) kegs so I was able to keg wine and have it on tap in my wine cellar, how perfect? After a just short time of working with these kegs I fell in love with them, and quickly realized there are uses for these kegs other than just holding and dispensing wine, such as a fermenter, wine storage and a carbonator.

In this article I will outline the many great things about Corny kegs and give you a reason to get one, or buy a few more!

The norm for home winemakers is to ferment juice in a carboy or a bucket, but there are drawbacks to these two vessels. Carboys, being made of glass, can break if dropped and buckets are easily scratched allowing bacteria to reside in the scratches. A great alternative to these vessels is the Corny keg. With a few small tweaks, described below, or the purchase of a kit you can turn the keg into a primary fermenter for wine juice or ciders.

1.      For some ball-lock kegs you can remove the pressure relief valve in the lid and insert a piece of tubing and an airlock. For a pin-lock keg you can remove the "gas-in-pin" and place with a piece of tubing over the threads and insert an air lock into the tubing. Both of these methods allow CO2 to escape during fermentation.

2. Purchase an already drilled lid and insert a #2 bung and airlock into that, or find a cheap lid and drill your own. Either way works, chose which method is easiest for you.    

Once fermentation is finished you can rack out of the keg, clean it and rack back into it; the keg now becomes a storage vessel!
Adding an airlock allows you to
Ferment wine and cider in the keg.
This modification can be done to ball-lock
kegs too

Corny kegs make a great storage vessel for wines. In combination with inert gas such as nitrogen or argon it can act as a variable volume tank, without the cost of an actual variable volume tank. This is helpful when you come up short on five gallons and you’re scrambling to find vessels to contain all of your precious vino! This is also great for storing topping wine when aging in barrels. This works by ensuring your sulfite levels are in range for storage of wine (0.8 molecular for whites and 0.5 molecular for reds.) Once your So2 levels are in range, rack your wine into the keg and close up the lid and connect the gas. Once the gas is connected it just needs 5-10 PSI to fill the headspace in the keg. After the gas has entered the keg, remove the gas and pull the pressure relief valve on a ball-lock keg or depress the poppet on the gas side on a pin-lock keg to purge the oxygen out the of the headspace. Reattach the gas and repeat this process a couple of times to ensure most if not all of the oxygen is out of the headspace. Even if you have a full five gallons and are able to fill the keg completely, I still recommend using inert gas because kegs do not have a neck to top up like a carboy does.

One thing to look out for is air leaks out of the keg. This is performed by spraying star san or soapy water on the lid. If you see any bubbles, there is a leak, and it will need to be addressed.  Leaks may be due to loose pins, a lid not seated properly, or defective O-rings. A few of my recommendations are: 

1. Turn the PSI up to 30 to help seal the lid. (The high pressure is eventually released on the first round of purging the headspace)

2. Use keg lube on the O-rings (food grade petroleum jelly)

3. Always have spare O-rings on hand in the case of an O-ring failure.

Although all or most of Oxygen has been purged from the headspace you should consider SO2 testing every one to two months and make sure the keg still has pressure throughout the storage period (or you could just keep it connected to the gas.) For testing during the storage period all you need to do is connect the cobra faucet and dispense what you need for a taste, pH measurement and a Sulfite test. There is no need to sanitize a wine thief or siphon hose, even better! To make any additions to the wine while it is in the keg you will need to release all pressure from the keg, open the lid, make your additions, replace the lid and repeat the oxygen purging process again.

Once the wine has sufficiently aged, you now have the choice to serve it as is or carbonate it with the same keg you have used as a fermenter and a storage vessel!

 Have you ever wanted to make sparkling wine, but the thought of riddling racks and PPE (personal protective equipment, it can be dangerous riddling those bottles, you know?) was a little daunting? Well look no further than your now multi-use Corny keg! Although a fridge is needed to carbonate, this is a very easy way to go from still to bubbly in no time.

My method is to bulk age the wine until it is ready to drink and has aged to my liking. I transfer the wine into the keg after normal cleaning and sanitizing procedures, connect it to Co2, and place the keg in the fridge. I use this carbonation chart: (http://www.kegerators.com/carbonation-table.php) this helps me get the PSI I want at the temperature of my refrigerator. Although this is geared toward beer, I find it helpful in guiding me toward the carbonation level I want in regard to the temperature of my fridge. After some experimentation I have found what PSI and temperature settings I prefer and I encourage you to do the same.  For example I leave the wine sit in the fridge for up to two weeks at 40F at 10 PSI. After two weeks I start sampling the wine to see how the carbonation level is doing. If I like it where it is I leave the PSI level where it is, if not I will turn it up a few PSI and allow it to sit longer. Wine should be cold stabilized to prevent tartrate crystal precipitation prior to placing it in the fridge for carbonating.

Once your wine is carbonated it doesn’t have to be confined to the keg, you can bottle it without a pricey counter pressure bottle filler. All that is needed for bottling sparkling wine is the cobra faucet and a racking tube to fit into the faucet. A #2 bung is placed on the racking cane to make a seal in the bottle.  

The method to this is:

Remove the gas-quick disconnect from the keg, and release the excess gas from the kegs headspace and turn down your gas regulator all the way. Reconnect the gas and turn your regulator up to about 5 PSI. Sanitize the pieces of the bottler, put it together and connect it to the keg. At this time you can start filling bottles. When making a seal in the bottle with the #2 bung, pressure will build up in the bottle and the flow will stop, that means you will need to release the small amount of pressure as you fill the bottle. Once the bottle is filled you can close it with a crown cap. This method is effective and much less expensive than other bottling methods for carbonated beverages. I will say it helps the CO2 stay in the wine if your bottler and bottles are chilled first. You can also go a couple PSI above what you originally wanted to compensate for any possible CO2 loss from the wine

*A note about bottles: while I usually carbonate my wines and ciders to 10-15 PSI, I am able to safely bottle in beer bottles for transport to give to friends. Whereas sparkling wine can go all the way up to 70-80 PSI! Corny kegs have a max PSI of about 130, so making sparkling wine is possible in these vessels. But I recommend you research further on working with such high carbonation levels and therefore I highly recommend using actual champagne bottles to avoid exploding bottles.

Elcheapo bottler for sparkling wine and ciders


I hope I have created some excitement in the various uses of the Corny Keg as well as expanded your understanding of how to temporarily modify the kegs for fermenting, storing and carbonating.  They are dependable, they will survive a drop or two or three (I mean just look at some of them) and you can find them pretty cheap if you’re adventurous at garage sales etc. Another great thing is their footprint is smaller in the winery than a 5-gallon carboy. Although you can do most of the steps in the winemaking process with one keg, it really helps to have a couple, a few, oh alright ten Corny kegs!   

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