I used lemons and limes that we had purchased in bulk at Costco®, cut in half, vacuum sealed and frozen. On thawing them in the microwave oven they once again were perfect for the juice extractor. We had empty tonic water bottles and we surely had water and plenty of sugar.
Now I must digress to describe the device used to connect the bottle of water, etc., to the source of the carbon dioxide gas. First, some years back I searched the Internet to find information on carbonating beverages at home. Most of the sites were simply retailers of very expensive little seltzer units, but one had a truly creative design that I decided to make and use any time I wanted a carbonated beverage. I now describe that design.
Pep Boys® used to sell metal tire valves used for high pressure truck tires, in packs of two for a few dollars. These types of valves can be obtained from different sources, notably tire businesses that work on trucks. A bit of searching on your part in your geographic area will locate what you need. I know because I attempted to buy addition valves from Pep Boys® recently and learned that they no longer carried that product. So I walked to a tire business, Sullivan Tire Company®, and got some for free of much higher quality (made of thick brass)than those that used to be sold by Pep Boys®. You might guess that Sullivan's is now where I buy new tires. Well, let's get on with the discussion.
The bottom of the outside of the valve (of the old Pep Boys® product and other products) has a flat collar and above that threads and a shim and a nut. The inside spring loaded red colored seal assembly is removed from the tire valve by unscrewing it and it is discarded. The valve is used with the bottle cap by first drilling out plastic from the center of the top of a cap from a bottle of seltzer water to a diameter that will barely allow the valve to fit into the hole. The soft blue seal that typically comes inside the bottle cap is to be drilled also and retained. The valve is inserted through the hole from the underside of the cap, through the blue seal and the white cap. Then the shim and nut are put onto the stem and a small adjustable wrench is used to tighten the nut onto the top of the shim to make an airtight seal. Thus, the collar of the valve is on the underside of the cap and the plastic of the blue seal and the cap is sandwiched between the seal and collar below and the shim and the nut on the top of the cap.
Plastic high pressure tubing that you can buy at Home Depot® connects the top of the tire valve to the regulator on the tank of carbon dioxide gas. Simply use stainless steel hose clamps on each end to securely attach the tubing. A simple open/close valve is used to turn the gas supply to the tube on or off. See the photographs below.
About 35 pounds per square inch (psi) pressure is set via an adjustment screw on the secondary gauge of the tank regulator as that will be perfect to force the carbon dioxide gas into solution in the bottle. After connecting a bottle of ice cold water (use your deep freeze to make it very cold, with a little ice, but not completely frozen) to the cap and valve unit you turn on the gas supply and shake the bottle vigorously for 30 seconds. Then you close the gas supply valve and unscrew the cap and valve unit from the bottle of now carbonated water. Actually, you unscrew the bottle from the cap and valve unit. You then screw on the regular bottle cap tightly and that is all there is to it.
Note that while this recipe is for lemon-lime soda that you can use root beer extract or any of many other flavorings to create the soda you want. Technically, you can buy Coke® syrup wholesale in a one gallon bottle if you can find a supplier. As always, you have to go looking to get what you want, but it is mighty easy online.
I strongly recommend visiting a web site named www.naturesflavors.com where you will find flavor concentrates for anything you might imagine. They have 287 different types of flavor concentrates. I used them to purchase the black raspberry concentrate I use when making black raspberry ice cream. The flavor concentrates can be used in many ways besides ice cream and beverages, for example, baking or puddings, salads, fruit salads, etc. The flavor choices go far beyond fruit flavors too. All prices are the same.
A word about cost is in order. I buy the one gallon quantity of concentrate to get the best volume pricing. It costs about $114 and that includes the shipping. That sounds very expensive until you realize that a gallon of concentrate will make 768 liters of soda, so the cost per one liter bottle for the concentrate is only 15 cents. The concentrate is very stable but if you want to guarantee freshness for many years then freeze most of it in 4 oz. or 8 oz. vacuum sealed packs and use them as needed. You might also split the cost and the product between four or more friends, and that simple act makes the cost easy to bear … and everyone gets to have fun.
Let’s look at the cost of the other ingredients to get a complete picture. The carbon dioxide gas will cost 6 cents. One pound of sugar is about 2½ cups. We buy sugar at Costco® for $14 for 25 pounds. Thus, the cost of the sugar to make one liter of soda is 14 dollars divided by 125 bottles, or, 12 cents. The really good part is that sodas made with sugar instead of the high fructose corn syrup used in commercial sodas taste one hell of a lot better. As usual, it is a quality of life issue.
Thus, to make one liter of very high quality soda will cost you a total of 33 cents, if you use the concentrate. If you use fresh fruit the cost will be 78 cents per liter, but you get a nice dose of vitamin C and superior taste. If you buy one liter bottles of soda at the supermarket the cost will vary from 79 cents to well over a dollar a bottle, you get no vitamin C, and the taste is inferior due to the use of high fructose corn syrup. To make things even better, you are recycling bottles and saving the environment!
Ingredients:
1 lemon (or buy lemon-lime concentrate from www.naturesflavors.com and use
1 lime about one half teaspoon (or less) of the concentrate)
1/2 cup of sugar
1 liter plastic soda bottle and cap
Water (I use the already chilled water from our refrigerator outlet)
Directions:
Extract the juice from the lemons and limes and pour it into the soda bottle using a strainer and a funnel. That will eliminate the fruit pulp and any seeds.
Alternatively you can use a lemon-lime flavor concentrate and put it directly into the soda bottle.
Add the sugar using a funnel and fill the bottle about half full with water.
Cap and then shake the bottle to dissolve most of the sugar.
Fill the bottle to within 1½" from the bottom of the neck with water.
Cap the bottle tightly, shake it again, and put it into the deep freeze for about 1 hour in the coldest place in the deep freeze. Some ice should form during that time, but not much.
Remove the bottle from the freezer, stand it upright and remove the bottle cap and connect the carbonation cap and valve assembly tightly.
Turn on the gas pressure valve.
Shake the bottle vigorously for thirty seconds.
Shut off the gas supply valve.
Stand the beverage bottle vertically.
Remove the cap and valve assembly from the carbonated beverage bottle, allowing some gas pressure to release gradually, without losing beverage, by alternately loosening and tightening the cap.
Screw the regular cap onto the bottle tightly.
Refrigerate the bottle of soda until you are ready to serve it.
Serve. It will be very well carbonated and very tasty.
Enjoy … and laugh about the retail price and the inferior flavor of the soda sold at the supermarket. Get kudos for reusing the plastic bottles/saving the environment.