I made a batch of OpenCola a few years back, I actually prefer the taste in comparison to that of Coca Cola. Brew up the syrup and get yourself a Soda Stream or any other carbonation device and you've got a tasty cola you made yourself.
Word of warning, making this stuff is SUPER expensive compared to just buying some Coke from the shop. All of those oils are not only hard to find (especially in Australia), but can be quite pricey when you total them up. Neroli oil is expensive in itself (about $25 AUD for 10mls of the stuff) follow the recipe right down to every warning (you could easily end up poisoning yourself if you make it incorrectly). Remember to get food grade, 100% undiluted oils or you could make yourself really sick or as I said, poison yourself.
I skipped the caffeine in mine and it seemed fine without it, but probably would taste better with it. I did notice something was missing, not sure if that's due to the lack of caffeine though I skipped primarily because the dangers of caffeine and the fact small amounts can actually kill you.
Don't go making this if you're expecting a 1:1 Coke copy. This has its own unique taste, slightly syrupy. I think the recipe definitely needs more work, but considering it's a free and open sourced recipe it's pretty good as it is.
> Word of warning, making this stuff is SUPER expensive compared
Not really. Sure, 5ml of neroli oil costs about $40. But that is enough for 20 batches of 7X formula.
I haven't calculated exactly, but a batch should yield about 40-60 liters of cola. The other ingredients are maybe around $40 in total. So 800-1200 liters of soda for maybe $80-90. That's pretty cheap.
As for oils being hard to find: That must be Australia. I ordered all of mine from G. Baldwin & Co. [1] in the UK. There are plenty of good sources in the US, too.
I love this recipe. I make it now and then so that I have a glass of syrup in the fridge that I can mix with carbonated water from a cartridge system.
(For a while we had the cola on tap in the office via a carbonator, alongside a colleague's home-brewed beer. It was very popular.)
I easily prefer this recipe to commercial Coca-Cola. On the one hand, it does lack a certain something that Coca-Cola has, and I attribute this mainly to the fact that I don't use any coca-leaf extract; you can get this online, and it ultimately comes from the same source as Coca-Cola uses, but I haven't bothered.
But on the other hand, it just tastes better. Fresher and more vibrant. Very different from off-the-shelf cola syrups such as SodaStream's. It's closer to a "indie" cola like Fentimans or Boylan's. My hypothesis is that Coca-Cola's current "natural aroma" ingredients are no longer natural essential oils, but synthesized versions of these, although I have not been able to confirm this.
I am talking about denatured ("decocanized") leaves and leaf extract. In the US, these are ultimately from Stepan, who is the sole American company authorized by the DEA to import and process cocoa leaves. This is coincidentally the company that Coca-Cola buys their denatured coca leaves from.
Thanks for the clarification. I've Googled around and can't find any decocanized sources online. Seems like it would be an interesting business opportunity for someone in South America. I bet Coca-Cola would find some way to put a lot of pressure on you, though.
There is this [1] source. Apparently it's intended for weight-control supplements [2]. Unfortunately, it's $1,000 per kilogram, with a minimum order of 5 kg.
Just in case you don't know, cocoa and coca are two very different plants. Cocoa (or cacao) is the one chocolate comes from, and I'm pretty sure you can own leafs of that.
The author mentions the soda stream carbonation doesn't really produce the desired effect. A tangentially related question: How does commercial carbonation work? Is it just keeping the liquid under pressure for a while with CO2 present? Is it done on a per bottle / can basis, or is it done in big vats and then sealed quickly afterwards?
Commercial carbonation is simply done by pressurizing water together with CO2. It's done in big vats, and the bottles are filled and immediately sealed.
For a while we had our cola on tap in the office (and we'll probably do it again). We used the same carbonator system we use for the beer tap, which is basically a CO2 tank hooked up to the source liquid, like this [1], and which injects the CO2 into the water on demand. It's the same principle used in soda fountains. It doesn't scale to real bottling operations, though.
As for the article, I disagree that "the soda stream carbonation doesn't really produce the desired effect". I have an off-the-shelf carbonation system that's similar to SodaStream, and it works really well. But these units vary a lot in carbonation quality, so it may be that the author of the article did not have a good enough carbonator. The important factor is the size of the bubbles; smaller bubbles means they last longer and provide a "fuller" effervescence.
This YouTube video I came across earlier today briefly explains the matter of achieving good carbonation (though not in a commercial or mass-production setting): https://www.youtube.com/watch?v=2V7ykGolWjg#t=3m45s
In short, it says that you need to remove the air inside the bottle before carbonating, and then carbonate over multiple passes while letting excess gas out of the bottle between the passes.
I have not researched the matter any further and can not make any claims regarding the quality of the information.
A commercial place uses very cold water, this keeps the CO2 in solution while they bottle it. With room temperature water all the CO2 would escape before they managed to get the cap on.
They fill a large tank with cold water and pressurized CO2, and mix. Then fill bottles and cap. It's a continuous process, so they pump water under pressure into the tank, and CO2 as well to make up for what they fill.
If you have ever been to a bar or restaurant, they use boxes of syrup for the soda. It is pretty much mixed with water along with C02 from a tank. They use plastic lines that run together and form at a water spout with different buttons for different drinks. The best tasting sodas are the owners who use a stronger concentration of syrup and CO2.
This stuff is super tricky. I tried experimenting around, e.g. doubling the amount of orange oil to make it more organge'y tasting. But it had in my opinion very little impact on the overall taste. It is really hard to get that stuff right. If you have a few $ to spare give it a try.
It is fun, but very very time consuming because you need to stretch ~10ml into 7gallons of water until you can know if you are on the right track.
Personally, my only change to the recipe was to subtract 0.25ml of cinnamon oil, because otherwise the cinnamon is somewhat dominant.
I have also experimented with adding vanillin, which I believe commercial Coca-Cola contains, but which is curiously absent from the OpenCola recipe. It's great, though you end up pretty much with Vanilla Coke.
As for those 7 gallons: If you want to experiment you can scale down the formula/syrup quite a bit to avoid that problem. Just add a drop or two of formula to a certain amount of water, and then add the same weight of sugar (eg., 100ml water = 100g sugar), and then continuing adding another drop of formula until the syrup balance is right. The citric acid and caramel colour isn't needed for taste experimentation. Now you can either mix some syrup with carbonated water to taste the mix, or you can just taste the syrup directly. (I bet a real flavourist with a sensitive palate will be able to just mix the formula with some still water and taste that without any sugar, though.)
The real problem is that you have to properly emulsify the formula when changing the balance of ingredients. But you can make the process easier by doing a base emulsion and using that to branch off of. For example, if you want to see how it tastes with more orange and less neroli, make a base formula with everything in place except no neroli, then pour off some of the formula, add a bit of orange, re-emulsify, and then make a small syrup batch from that. Time-consuming, sure, but doable.
The recipe is correct. The concentrated syrup is 50% sugar by weight, but it's mixed 5:1 with carbonated water, so you end up with about 100g of sugar per liter of finished soda, which is pretty much the same as in commercial Coca-Cola.
A few month ago I tried brewing this stuff myself. It "kinda" works, but it tastes inmho very different from "regular" Coke. It tastes a bit more along the lines of RedBull Cola.
You could add the oil mixture to maltodextrin to turn it into a powder until it is hydrated where it will turn back into a slightly sweeter version of the oil mixture. Maltodextrin is really quite cheap. It's not a startup idea though...
Word of warning, making this stuff is SUPER expensive compared to just buying some Coke from the shop. All of those oils are not only hard to find (especially in Australia), but can be quite pricey when you total them up. Neroli oil is expensive in itself (about $25 AUD for 10mls of the stuff) follow the recipe right down to every warning (you could easily end up poisoning yourself if you make it incorrectly). Remember to get food grade, 100% undiluted oils or you could make yourself really sick or as I said, poison yourself.
I skipped the caffeine in mine and it seemed fine without it, but probably would taste better with it. I did notice something was missing, not sure if that's due to the lack of caffeine though I skipped primarily because the dangers of caffeine and the fact small amounts can actually kill you.
Don't go making this if you're expecting a 1:1 Coke copy. This has its own unique taste, slightly syrupy. I think the recipe definitely needs more work, but considering it's a free and open sourced recipe it's pretty good as it is.