Ball Lock Corny Keg: Home Brew Fermenter

Wooden wine barrels are a lot of commitment in terms of space, cost, and care for most homebrewers. Instead what we recommend is using a ball lock keg and oak chips. For more details refer to this guide.

While beer brewers add just 8gm of sugar per liter of beer, sparkling wines, cider, and champagne need 16 to 25gm of sugar to create that loud distinct pop sound when you uncork a fully pressurized bottle.

Note: Be careful to use only stainless steel kegs or extra thick glass bottles. Normal glass bottles and water bottles are not meant to withstand this pressure and tend to burst.

Typically bottled home brew beer has a shelf life of 6 months. However, most home-brew beer is consumed within a week to a month of bottling or kegging. However, some people regularly store homebrew beer for up to 6 months successfully. Beyond this, the beer is still safe for consumption, just that it will not taste fresh. However, a couple of factors need to be taken into account to determine the shelf life.

1. Storage temperature: Beer is like wine, higher the temperature the faster is the degradation in flavors.
2. UV light: Even a couple of hours in direct sunlight can ruin a perfectly fresh beer
3. Packaging: Microbrewery Growlers don’t last 2 days because the beer was oxidized during filling. If you see packaging in proper crown sealed glass bottles or stainless steel kegs, 6-12 months life is easy
4. Oxidation: Once you open the bottle, drink within an hour.

Kombucha traditionally is made in a glass or porcelain fermenter. We would strongly recommend you to start in a similar mason jar or a pickle jar that is typically found in Indian kitchens. Tie it with a muslin cloth (or handkerchief) to prevent insects from dropping by.

As you scale your kombucha, we would recommend you to use either:

1. Conical fermenter: This allows you to rapidly clean the sediment without disturbing the SCOBY. Hence, you can ferment faster and scale up your enterprise.
2. Another option is to ferment in a Corny Keg. These are inexpensive and allow you to produce very good quality natural carbonation. You can sell and transport in the kegs as well. This allows you to scale up fast.

A Cornelius keg (also known as a Corny or Corney or soda keg) is a beverage keg originally made by Cornelius. It is a stainless steel canister designed to withstand huge pressure (120psi 4 times what is there in your car tyre).

They are ideal to store, dispense, carbonate, and even transport sodas, beer, champagne, kombucha, and ginger ales. Its unique three mouth design makes it easy to clean and maintain kegs over many years. Also, its long slender design makes it easy to refrigerate and store in tight spaces like your chest freezer.

Kegs are easy to maintain. A standard 11/16 x 7/8 in. wrench is sufficient to remove the keg ball lock posts and dismantle the keg for cleaning or repairing. However, we will recommend you to buy 7 in 1 spanner. As it can help you with your beer lines and beer taps as well. It is ideal for all microbrewery purposes.

A corny keg has 3 inlets and a PRV (pressure release valve). To fill the keg, open the large oval lid to fill the liquid. Use the gas inlet to fill in CO2 and the liquid inlet to dispense.

How to fill a Corny Keg UPDATED (Simple, LODO, & Closed Transfer)

Watch this video on YouTube

Corny kegs, don’t have any markings. This makes it difficult to set up for the first time. To find out which side to connect with CO2 gas and which side connects to your beer lines, there are 3 ways.

1. Dip Tube

Open the keg and try to feel the inside of the keg posts. The liquid line will have a long dip tube going all the way to the base of the keg. The gas line will have a shorter inch and a half stainless steel tube (as shown in the picture)

2. Keg Post Construction

If you are unable to open the keg (because it is pressurized or filled), then look at the keg-post construction. The gas post is smoother while the liquid post has a ridge design. As shown in the picture.

3. Ball Lock Connect

Find the ball lock connect on which Gas is written (usually the white/grey in color) and connect it to the keg posts. If it fits then you are golden. However, this is the least reliable method as modern keg connects fits both ends. This is because some home brewers like to force carbonate their kegs by pumping CO2 from the beverage end instead of using the carbonation lid.

Typically I fit in 7-8 kegs in a chest freezer aka Amul ice-cream refrigerator. Just attach a thermostat and you are good to go. You can buy your keezer attachments here.

If you are unsure how many kegs you can fit in, cut out 8.5 inches circular discs (you can also use serving plates of 8.5-9 inches diameter). Place it inside the refrigerator to cover the area.

If you are trying to fit your corny homebrew keg in a fermentation chamber or mini-fridge, just make sure that you have knee-length height in your keg which is 25 inches for 19L and 14.25 inches for 9.5 Liters version (plus an additional inch or two for maneuvering)

Your beverage serving cans are made of aluminium. Kegs are made of SS304. Reasons are:

1. This allows it to store highly acidic homebrew like cider, mead, and wine. (Even gose style beers and lambic beers).
2. Also aluminium is a soft material prone to scratches, while stainless steel is tougher. This prevents contamination from hiding in the scratches and ruining your brew
3. Aluminium cans are coated with a food-grade resin coating from inside to be able to withstand corrosion. This mechanism is good for disposable containers. However, kegs are supposed to be re-used. Hence checking the coating integrity every time you empty them is going to be tedious. So kegs and equipment used in the beverage industry are made from Stainless Steel and not Aluminium.

Bottle beer goes bad for three reasons:

1. Exposure to sunlight: Beer is sold in brown bottles so that UV and sunlight is blocked. However, still some sunlight goes in the bottle. Sunlight reacts with hops and alcohol to create skunk beer. Corny beer kegs are made of opaque stainless steel. Hence there is no scope of UV or sunlight reacting with your beer. Hence UV skunks or bad beer does not happen in kegs.
2. Oxidation: One of the reasons why bottled beer has an expiry date is because of micro-oxidation at the crown cap crimping. Over 6 months this steel joint on the glass bottles can become loose and oxidize the beer. Corny Keg and aluminum cans have a much tighter seam and hence no oxidation. Brewers worldwide have aged sparkling wine and beer in kegs for 2 years without any apparent oxidation.
3. Heat Staling: Hoppy bears are prone to getting stale cardboard-like off-flavors when exposed to high temperatures for extended periods. The kegs are usually taken better care off. Unlike the glass bottles that often are transported and stored in the open and outside refrigerator. Hence chances of heat damaged beer in a keg is negligiable.

Essentially can beer tastes better than bottled beer. Keg beer tastes best.

Another problem with bottled beer is that once it loses its CO2, it goes flat. There is nothing much one can do to resurrect this beer. However, in a keg, one can always force carbonate and get the fizz back. Unless there is dissolved CO2 and pressure, one cannot pour the beer. So be assured your keg beer will always have foam.

If you are still confused like I was when I started:

1. Pressurize the keg at 30PSI for 24 hours to achieve full carbonation.
2. Cool keg to 4 degree to achieve maximum CO2 saturation.
3. Vent off the pressure to reduce it to 12PSI.
4. Try to dispense beer. If it does not work reduce the pressure to 16psi for more foam or 8psi for lesser foam.

Professional Answer to Keg Pressure

It is hard to figure out what is the ideal pressure for everyone as it depends on multiple factors:

1. Temperature. The solubility of CO2 varies exponentially with the lowering of temperature. At 4 degrees Celsius, the beer typically has 2.5 to 3 times its volume (~1L per 330ml pint) of CO2 dissolved in it. As the temperature rises this volume also goes down. Typically brewers report the pressure at the keg when it is chilled. If your keg is at room temperature, you need 10-15 PSI higher to compensate for this.
2. Where you are measuring. The pressure is highest at the CO2 cylinder where the regulator dispenses it. As it flows through the gas manifold, the keg connects, into the tank, and out the beer tap, the pressure drops. Think of CO2 pressure as the voltage and your beer line as resistance coils. More are the attachments, connections, splitting, and the longer the line more is the pressure drop. Most brewers report CO2 pressure at the regulator valve, however most books will talk about pressure at the dispensing tap. To cut the story short. There is no right bookish gospel truth. Based on your configuration the pressure will vary.
3. Beer Style: Not all beer foams the same. Also, not all beer styles need to be carbonated to the same level. Sparkling water tastes so different than normal tap water because of the dissolved carboxylic acid. The carbonation that you need depends on:
   • How much head you want
   • How much head forming particles (hops wheat etc.) in your beer
   • What style of beer you are serving
   • What is your serving temperature?
   • Luckily most beer style books have notes on the carbonation, ideal serving temperature, and pressure to get you started. However, don’t be bookish. Go by your own preference and craft beer signature.
4. How soon you want to carbonate and serve. Carbonation is a slow process. you could use the carbonation stone to accelerate it. Or you could pump in CO2 at very high pressure and roll the keg to dissolve it. As a rule of thumb: If you want to serve it within the next 3 days. Maintain pressure at 30psi and then vent off the pressure using a PRV (Pressure release valve) and serve at 12-16psi.