Force Carbonating Soda

If you have kids and you homebrew, before too long you will find yourself making soda (soda-pop for those of you midwesterners).  I too fell into this offshoot of homebrewing confident that with my knowledge of sugar and homebrewing this would be a walk in the park.  As usual, I was to learn that I don't know everything.

My first attempts followed the simple instructions found inside the container of Gnome Rootbeer Extract.  It seemed simple enough.  Get some water.  Add some sugar, yeast, and flavoring.  Put in a clean plastic bottle and wait.  Everything I read came with bold letters DO NOT USE GLASS and THIS WILL EXPLODE.  Fortunately, for once I paid attention.  A few days later, my soda bottle was rock hard and ready to drink.  Eager to taste my newest creation I poured a tall frothy glass of rootbeer only to discover that it tasted like root beer meets pizza dough.  No matter what type of yeast or how carefully I poured, I could not get past the yeasty flavor of the soda.  Quite possibly there is a way to do this better, unfortunately I never found it.

Not to worry, I can always force carbonate.  Afterall, this would give me another justification to my wife for why I spent so much money on a kegging system.  I decided to make a whole keg of rootbeer, completely confident that this plan was fool proof.  After filling up my keg with a delicious concoction of water, sugar, and rootbeer extract I placed my keg in the refridgerator to cool (armed with the knowledge that CO2 goes into solution better when the liquid is cold).  Following my normal force carbonating procedures, I connected the CO2 to the OUT port on my corny keg and cranked the pressure up to 30 psi(Note - at all points you must have higher pressure in the CO2 line than in the liquid container lest you fill your CO2 tank with liquid - a very expensive mistake).  After ten minutes of rocking the keg, I let it sit overnight.  The next morning I gathered the clan around to taste what Daddy had wrought.  Pulling a glass of rootbeer I discovered, a mildly carbonated rootbeer flavored liquid.

Off to the internet I went.  Scouring the internet I discovered scads of information about force carbonating beer but precious little about force carbonating soda.  Eventually, in the deepest darkest corners of the interwebs that even Al Gore doesn't know of, I found a brief explanation.  The article mentioned something about the high sugar concentration of soda makes force carbonating soda more difficult than beer.  It can be done.  Heck, that is how all commercial soda is carbonated, but in my attemptes it takes a bit more CO2 than I was able to bring to bear.

Not to despair, the article offered a solution.  The article suggested to take three or four gallons of water, chill them, and then force carbonate them.  Once the water was carbonated, make a gallon of a more concentrated syrup (using the sugar and extract quantitites for five gallons) and add it to the keg.  Brilliant why didn't I think of that?

Following directions like a good little soldier I did just that.  With my 4 gallons carbonated I carefully used the bleed off valve to remove the CO2 pressure off of the head space and prepared to carefully add my syrup.  Slowly pouring the syrup in the water rebelled.  It fizzed a bit... then some more... then exploded in a fountain of sugary carbonation all over my kitchen floor.  Quickly placing the lid back on the corny keg I knew there must be a better way.

Some people have had success carbonating their soda without pre-carbonating the water.  This may be due to a difference in soda recipes or perhaps a greater amount of headspace.  By all means, try a simple force carbonation first.  If however that does not work for you (or does not carbonate the soda enough) then this is an alternative.

Supplies

2 liquid connectors to connect to your corny kegs

Couple of feet of vinyl tubing with connectors on either end to connect to the liquid connectors

2 corny kegs (one to keep the soda in and one to use temporarily)

Procedure

1. Place four gallons of water in a corny keg and place it in the refridgerator overnight
2. Following the normal procedure for force carbonating connect your CO2 to the OUT post on the corny keg.  Increase the pressure to 40-50 psi.  Shake the keg until you can no longer hear bubbles entering the water.  Again let it sit overnight.
3. Make up one gallon of soda "syrup" using your favorite recipe.  Chill in the refridgerator until cool.
4. Pour soda syrup into second corny keg.
5. Remove carbonataed water from refridgerator
6. Attach CO2 line to the IN port on the keg containing your syrup at around 10 psi.
7. Using the bleeder valve on the top of the carbonated water, relieve any excess pressure
8. Using the vinyl tube with two liquid connectors, connect the syrup keg's OUT to the carbonated water keg's OUT
9. The syrup should begin moving from the first keg to the second.  Periodically "burp" the bleeder valve to ensure that the pressure remains unbalanced and the syrup moves over to the carbonated water.
10. Once all the syrup has been transferred I crank up the CO2 and attach the CO2 to the IN post for a few days.  Soda is typically much more carbonated than beer.
11. Let the soda sit overnight and dispense as you normally would

Page by:Chris "Pasteur" Rafalik

Date: January 2, 2009