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Hey all,

Thanks for all the help so far. I got my first CO2 tank, and the Cider is great; however I notice that carbonating via CO2 tank vs. bottle fermentation makes the cider slightly more bitter. Any suggestions on a counter-action?

P.S. When do you guys meet at Rock Bottom?

I've heard some guys say they get CO2 bite from force-carbing that goes away after a few days. I can't say that I've noticed and difference, but then again, my co2 bitterness is masked by hops.

We get together...whenever. Just keep your eyes open, or post in the RB thread when you're going down, maybe you'll get company.

Cool thanks!

Ciderhead, what PSI are you set to and at what temperature?

mr x wrote:I've heard some guys say they get CO2 bite from force-carbing that goes away after a few days. I can't say that I've noticed and difference, but then again, my co2 bitterness is masked by hops.

When Co2 is dissolved into solution it becomes carbolic acid, it lowers PH and has an effect on how you perceive flavour plus CO2 is a flavour carrier. Regardless, when the state of fluid is altered it needs time to mellow, the flavours need time to become one. I mostly force-carb beer in breweries and they are always better after a rest period, at least one day but ultimately it takes a good 3 days for things to settle in to their own. Also, if you are carbonating to a higher level than usual the added acidity will give it more bite since it's more acidic

Ah, that makes sense. What is a proper PSI for carbonation? I have been going with 35 PSI.

Ciderhead wrote:Ah, that makes sense. What is a proper PSI for carbonation? I have been going with 35 PSI.

Do you know how many volumes CO2 you want to carbonate to? Typical cider is carb'd to ~ 3.0 vols. It depends on the temperature of the cider but if your fridge was at say 40 F you'd want 18 PSI to reach 3.0 vols

See attached chart

Would you mind defining 'volumes CO2' in this context? Thanks.

KMcK wrote:Would you mind defining 'volumes CO2' in this context? Thanks.

My guess is that 1 volume of co2 would mean one litre of cider/beer would have 1 litre of co2 dissolved in it. i could probably tell you for sure if i used the google

1 volume is 1 liter of CO2 at 20°C at 1 atmosphere in 1 liter of beer.

CorneliusAlphonse wrote:

KMcK wrote:Would you mind defining 'volumes CO2' in this context? Thanks.

My guess is that 1 volume of co2 would mean one litre of cider/beer would have 1 litre of co2 dissolved in it. i could probably tell you for sure if i used the google

I can use the google too but for some things I prefer the Nash.

A volume is the space that the CO2 would take up at a pressure of one atmosphere (about 14.7 pounds per square inch which is actually 0 psi gauge) and at a temperature of 0° C (32° F) — that’s Standard Temperature and Pressure (STP). In other words, if five gallons of beer contained three volumes of CO2, the CO2 by itself would occupy three times the space the beer takes up, or 15 gallons. An average carbonation level is 2.5 volumes of CO2.


Carbon dioxide has a density at STP of 0.122 pounds per cubic foot, or 1.94 grams per liter.

Sometimes the level of carbonation of beer is given by weight rather than by volume. The conversion factor from volumes to CO2 by weight is 0.194. For example: 2.5 volumes x 0.194 = 0.485 g/l. To convert to volumes, multiply by 5.147 (the inverse of 1.94).

Carbon dioxide has a molecular weight of 44.01 and glucose has a molecular weight of 180.16. During fermentation each molecule of
glucose creates two molecules of ethyl alcohol and two molecules of CO2. A mole is the number of molecules that has a weight in grams equal to the molecular weight of the molecule. That means that one mole of glucose weighs 180.16 grams and ferments to produce two moles of carbon dioxide weighing 2 x 44.01g = 88.02 g.

Say you want your five gallons (18.93 liters) of beer to have 2.5 volumes of CO2. That’s 18.93 liters x 2.5 volumes = 47.32 liters of CO2.

Since a mole of CO2 occupies 22.414 liters (STP), we need 47.32 / 22.414 = 2.11 moles of CO2. This will be produced by half that many moles of glucose, or 1.056 moles. Multiply by the molecular weight of glucose and you find that you need 190.2 grams of glucose or 6.71 ounces.

If your fermentation ended at 50° F, you might have 1.2 volumes of CO2 in your beer already. That means that you need 1.3 volumes more CO2 to end up with 2.5 volumes. You could get that by adding (1.3 / 2.5) x 190.2 = 98.9 grams of glucose, or 3.5 ounces.

You can make similar adjustments if you have a different amount of beer or if you’re aiming for a different level of carbonation. If you want to carbonate to 2.8 volumes instead of 2.5, multiply by 2.8 / 2.5. If you have four gallons of beer instead of five, multiply by 4 / 5.

For example if you have 10 gallons of ale that you figure has 0.9 volumes of CO2 already and you’re aiming for 2.0 volumes, you need 1.1 volumes more. You calculate: (190.2 g glucose)(10 gal./ 5 gal.)(1.1 vol./ 2.5 vol.) = 167.4 g glucose (or 5.9 oz.).

When you’re adjusting to add more sugar (e.g. more beer), put the big number on top; when you’re adjusting for less sugar (e.g. less carbonation) put the smaller
number on top.

FYI.

A new study published in the Science journal suggests the increasing amount of carbon dioxide being absorbed by the seas is causing them to turn acidic with "unparalleled" speed.

If the trend continues it could have a variety of serious effects on marine life by slowing rates of growth, causing animals to produce fewer offspring and causing shells to dissolve, experts said.

well, maybe not so much

mr x wrote:FYI.

A new study published in the Science journal suggests the increasing amount of carbon dioxide being absorbed by the seas is causing them to turn acidic with "unparalleled" speed.

If the trend continues it could have a variety of serious effects on marine life by slowing rates of growth, causing animals to produce fewer offspring and causing shells to dissolve, experts said.

well, maybe not so much

Ocean acidification is a very scary problem, but since there is no solution the newspapers rarely discuss it. See: http://royalsociety.org/uploadedFiles/R ... 5/9634.pdf" onclick="window.open(this.href);return false;

It's bad news, unless we figure out how to eat oil.

mgc wrote:... but since there is no solution the newspapers rarely discuss it. See: http://royalsociety.org/uploadedFiles/R ... 5/9634.pdf" onclick="window.open(this.href);return false;

It's bad news, unless we figure out how to eat oil.

The solution appears to be a mixture of water and CO2 and it doesn't appear to be a very nice solution.