Home-made Water Carbonating Soda Machines

Carbonating water can be done in three different ways.  You can work the acid in to the water by shaking it, you can let time do the work for you, or you can overdose with carbonic acid and then let a portion of the acid evaporate.  With a Ritchie carbonator and similar devices,  you can add carbonic acid to water or even to wine and other beverages – something that cannot be done with a soda machine.  This process entails carbonating, waiting, carbonating some more, and so on. Quite frankly though, this process too difficult and lengthy when you just want a drink.

This video shows how to carbonate water using a home-made machine in soda-bottle.  After pressurizing, carbonic acid is shaken into the water.

This seems fine, as carbonic acid costs next to nothing in large CO2-bottles.  But the smarter way is utilizing over-pressure, as there is no waiting and no shaking.

All commercial soda machines use over-pressure.  And as carbonic acid is more solvent in cold water, it is best to use your refrigerator to cool it first.

An especially strong PET bottle is partially filled with water, as room is needed for pressure equalizing, just like in a purchased PET bottle.

Then you add carbonic acid until you hear the pressure valves release.  You then release the button, allowing the pressure to equalize.  If you want more carbonic acid, you can then repeat these steps.  You quickly learns what level of carbonation tastes the best.

This is a German video that shows how to carbonate water with a Sodastream.  The carbonated water is ready at once, either for drinking or for flavouring.

This is the best and smartest way.  The bottle is stronger than normal, and should be good for several years.

So why are there home-made machines?

Quite simply, to reduce the price of the carbonic acid.  The acid itself is virtually free, and with some suppliers the price is the same for five, ten or fifteen kilos, as what you are  actually paying for is not the acid, but the work entailed in refilling bottles, and some mark-up.  Refilling bottles of 2 kilograms and up, usually designed for restaurants and other small businesses, usually costs about 20 Euros, making the average price for a litre of carbonated beverages a few cents.

The Carbonic acid you buy for soda machines is quite cheap. At about 10 Euros per refill, this averages at less than 20 cents per litre.  As you can see, this is really cheap when compared to purchased carbonated drinks.  But when compared to the savings of bigger acid bottles, 10 Euros per refill, or more than 20 Euros per kilogram of acid, is really pretty expensive.

This is why many people today see this as excessive pricing and make their own soda machines so that they can utilize bigger canisters.

The soda machine producers on the other hand will make every effort to protect their golden goose.  Through making the customer sign different contracts and legal documents to be able to use their canisters, each producer has a monopoly on refilling their own bottles –  refilling of these has no real free market and the different producers cannot compete against each other.

During the 1980’s one could get refills at Partymans store in Malmö in Sweden, free if you purchased three bottles of aroma.  The refills where supplied by Sydbrand at reasonable and competitive prices.  Sodastream consequently sued Sydbrand for trademark infringements, leading to years of legal action at great cost.

Today, every soda machine producer tries to stop others from refilling their branded canisters, using every legal means possible and with armies of lawyers.  All this, even though you can, in truth, easily refill a bottle in 20 seconds while a customer is waiting in a store.  This was done by a business in Germany, who in turn were also attacked by Sodastream, or Soda Club as they are called in Germany,

But Soda Club, or rather Sodastream, lost their legal battle.  Their trying to stop a bit of competition led to opening the field to totally free competition.  This in turn should be the result in all EU countries, thanks to EU legislation, but this of course depends on someone coming along who dares to challenge Sodastream, or by the authorities being woken up by consumers who no longer will accept the status quo.

Instead of making their own home-made machines I think people will use the great machines currently in existence, like Sodastream or Wassermaxx, and get cheaper carbonic acid, either through refilling the acid from larger bottles themselves or through hooking larger canister directly into their soda machine.

You can refill a smaller canister from a bigger one.

On bottles, it mentions how much carbonic acid they contain when full, normally 425 grams on newer machines, and 300 grams on the older gray Sodastream canisters.  You empty the bottle completely, and then put it into the freezer for a few hours.  You then hook the bottle in to a larger bottle, and place it on weighing scales.  Then you let in carbonic acid until the bottle is full and the weight is correct.

For this, you need a proper valve for the big bottle, as well as some good rubber hoses and couplings designed for the extreme pressure. Proper couplings and hoses are also needed if you can get large bottles and hook these directly into your machine.

Retailing these couplings could be a business idea for make-your-own-wine stores.  You could then refill your own bottles, or maybe have them refilled by someone who normally refills fire extinguishers or carbonic acid for fish tanks or for pubs.  Another idea would be to become a retailer for a slightly larger bottles, and for two to four-kilogram refills.

Perhaps someone will even challenge Sodastream.  A luxury-model CO2 pump costs about 4 300 Euros and a cheaper model perhaps half.  With one of these, one could refill carbon dioxide canisters in 20 seconds while the customer is waiting.  Through leasing refilling machines and distributing the cost of this over one or more years, a business such as this could get started without large cost.

The business itself won’t lower prices.  Wassermaxx is owned by AGA, and Airliquide has interests in other markets.  Through everyone protecting themselves one provider can’t ever refill the bottles of another.

However, a new generation of soda machines is moving in, with cooling systems and in-line carbonation, meaning no carbonic acid is lost.  This means carbonated water straight from the tap. These are actually small restaurant machines for home-use.  The water must be cold if you wants a proper level of carbonation, and so machines without cooling systems will probably disappear soon.  Models with cooling often carbonate better than soda machines, and even though they cost quite a lot, the carbonic acid can be bought in large bottles, making the carbonated water really cheap.