Bodgineering - DIY carbonation

[SafetyThird]

Thanks very much for that. Looks like I'd be better off getting a CO2 bottle locally. I get mig gas for welding from a local welding shop and I've just checked and they do Hobbyweld cylinders so it would be £90 deposit and £40 per fill on what looks like a 9 litre bottle. Should last me a while.

[Oldgreybeard]

Thanks very much for that. Looks like I'd be better off getting a CO2 bottle locally. I get mig gas for welding from a local welding shop and I've just checked and they do Hobbyweld cylinders so it would be £90 deposit and £40 per fill on what looks like a 9 litre bottle. Should last me a while.

Should indeed last a while. A 9 litre/6kg cylinder is roughly enough gas to carbonate about 850 litres of water, so about 5p/litre. A Sodastream costs about 38p/litre usually. If you re-use ordinary 1 or 2 litre pop bottles with a carbonation cap like the one linked to earlier, then you'd also be saving PET bottles from recycling, and I suspect it's better to re-use rather than recycle in terms of the environment.

[Swwils]

Ask them to cough up a certificate of purity and see if they will do it.

[Oldgreybeard]

Ask them to cough up a certificate of purity and see if they will do it.

Why?

Hobbyweld sell the gas as being "food grade" ( https://hobbyweld.co.uk/products/carbon ... ood-grade/ ), and they describe it as a "beverage gas", so I think it's fair to assume that it is safe enough for making fizzy drinks.

They sell three types of "beverage gases" and describe them like this:

Hobbybrew Beverage Gas

Hobbybrew beverage gas can be used for drinks dispense use; either at home or professionally in a pub, club, bar or restaurant.

We offer 3 gases in our Hobbybrew beverage gas range:

Carbon Dioxide is used primarily to carbonate drinks, but is also used as a propellant to push the drink syrup along the drink lines through your pump and into your glass. If you are looking for carbon dioxide for other purposes than what is outlined above, please see our Carbon Dioxide (Industrial Grade).

30/70 (30% Carbon Dioxide in Nitrogen) is used primarily for dispensing smooth/creamy stouts and ales.

60/40 (40% Nitrogen in Carbon Dioxide) is used for dispensing the majority of lagers and ciders.

[Fintray]

Ask them to cough up a certificate of purity and see if they will do it.

If you are that worried by purity, BOC sell a grade of CO2 that is 99.9995% pure, £980 a refill though!

[Swwils]

The purity is of massive concern, even around 20 PPB of benzene will leave whoever drinks it with headaches etc.

Just take care.

Yes. Food and beverage grade co2 can be the same purity, typically 99.95% purity rating - but what the impurities are is vital, there is no guidance in what they can be marketed or named as (apart from medical grade) so you'll need to check the source plant and spec sheet.

Food grade CO2 is not meant for human consumption, so actually you need beverage grade gas and a distributor will be able to source you the right stuff for carbonising drinks.

[Oldgreybeard]

The purity is of massive concern, even around 20 PPB of benzene will leave whoever drinks it with headaches etc.

Just take care.

Yes. Food and beverage grade co2 can be the same purity, typically 99.95% purity rating - but what the impurities are is vital, there is no guidance in what they can be marketed or named as (apart from medical grade) so you'll need to check the source plant and spec sheet.

Food grade CO2 is not meant for human consumption, so actually you need beverage grade gas and a distributor will be able to source you the right stuff for carbonising drinks.

Given that every bar and pub in the land uses large amounts of "beer gas", from many different distributors, and given that our local one told me categorically that they use the same gas to fill any CO2 cylinder, isn't this just a wee bit OTT? Also, the link was specifically for beverage grade, anyway, the name "Hobbybrew beverage gas" is a bit of a giveaway.

How many people a year die as a consequence of drinking beer that has been gassed with impure CO2? For that matter, given that we import large quantities of carbonated drinks, and we have no way of knowing how pure the CO2 was that was used in their manufacture, how many deaths from drinking fizzy drinks carbonated with poor quality CO2 are there each year?

It strikes me that this is amplifying a very tiny risk, that doesn't really pose a significant problem for someone making a few litres of fizzy water. The risk of there being some contaminant in the water or flavouring is probably massively greater than the risk of being killed by something in the CO2, IMHO. The one case I could find related to contaminated CO2 was from 24 years ago, and even then the medical view was that the 20ppm benzene found would only pose a risk to those drinking more than 40 litres per day of the contaminated soft drinks.

FWIW, burning hardwood in a wood stove releases around 1g of benzene per kg of dry wood burned, so absolutely masses more than the 20ppm level from the 1998 incident. 20ppm in a litre of water is just 0.02g, just 2% of the amount of benzene emitted from burning 1kg of hardwood in a stove.

[Swwils]

The QC for carbonising gas in the large soft drink brands and stream devices is very robust, down to the point in which the individual plant will produce only the specified co2 for them and they will not accept gas from other plants.

Even after that it is further checked with gas chroma, IR spectro, flame ionization hydrocarbon analysis and trace O2 analysis.

And that's just catalog spec from the typical gas companies like Air Liquide, Linde etc. Distributors will also provide the info when asked. Some gas suppliers are dedicated to bev carb and will do that and that only.

[Oldgreybeard]

But where is the risk from using beverage grade gas, though?

No one checks imported carbonated drinks, like everything else we got rid of all checks on products that are imported and adopted a daft system of trust where suppliers self-certify what they are selling. As we know, manufacturers cheat all the time, especially some in far-off lands that make up quality certification for a pastime.

I still contend that there is a far greater risk from stuff in water or flavourings than there will be from using beverage gas, and that this is creating a concern that is out of all proportion to the real risk. Everything we do is risky, so we should all decide what an acceptable risk level. I can't find any data at all on deaths from contaminated CO2 in fizzy drinks, but I can find masses of data on deaths from other everyday things. I think we just need to have a sense of proportion as to how serious any risk is.

[smegal]

The QC for carbonising gas in the large soft drink brands and stream devices is very robust, down to the point in which the individual plant will produce only the specified co2 for them and they will not accept gas from other plants.

Even after that it is further checked with gas chroma, IR spectro, flame ionization hydrocarbon analysis and trace O2 analysis.

And that's just catalog spec from the typical gas companies like Air Liquide, Linde etc. Distributors will also provide the info when asked. Some gas suppliers are dedicated to bev carb and will do that and that only.

Surely the most widely available bottled CO2 is "pub gas" that would adhere to all of the relevant standards any way?