Homebrew carbonation different?

[Mateo]

It has always perplexed me how homebrew carbonation is different from commercial beer. I could never put my finger on why. The bubbles are smaller and smoother. The bubbles in commercial beer are big and have a very different mouth feel.

Does anyone know why?

 

[Schnitzengiggle]

I'm just guessing here: force carb vs bottle carb?

 

[BlueSunshine]

I'm just guessing here: force carb vs bottle carb?

That's what I was thinking.

Homebrewers that use bottles carb their beer exactly like they used to carb soda in the old days.

 

[bovineblitz]

I believe bottle carbing generally results in smaller bubbles while force carbing results in bigger ones.

 

[Schnitzengiggle]

That's what I was thinking.

Homebrewers that use bottles carb their beer exactly like they used to carb soda in the old days.

I believe bottle carbing generally results in smaller bubbles while force carbing results in bigger ones.

I am getting ready to fill my first keg this weekend, and I won't be drinking it for about another week or two, so like I said it is just a guess, maybe someone who knows more about the science will chime in.

 

[pcollins]

Yes, force carb vs natural carbonation.

I don't know the exact science behind it but one would think that CO2 is CO2 but in this case they do seem different.

 

[ChrisS68]

I believe its more a factor of carbonation levels and viscosity - protiens, dextrins, final gravity. Most commercial beer is thinner and highly carbonated, hence the larger bubbles.

 

[dorklord]

My guess would be filtering has something to do with it. The filtering that commercial beer goes through would reduce the number of nucleation sites for the CO2 to come out of solution, which should mean fewer but larger bubbles. Things like the yeast in your homebrew will provide more nucleation sites, so the CO2 will form more bubbles.

I'm sure the degree of carbonation makes a difference as well, but I wonder if it would affect the number of bubbles, or the size of the bubbles more?

 

[Schnitzengiggle]

I believe its more a factor of carbonation levels and viscosity - protiens, dextrins, final gravity. Most commercial beer is thinner and highly carbonated, hence the larger bubbles.

Personally, I have noticed some of my bottle conditioned beers that had much larger bubbles than others, so your hypothesis is valid. More dextrinous beers may make for tighter bubbles.

My guess would be filtering has something to do with it. The filtering that commercial beer goes through would reduce the number of nucleation sites for the CO2 to come out of solution, which should mean fewer but larger bubbles. Things like the yeast in your homebrew will provide more nucleation sites, so the CO2 will form more bubbles.

I'm sure the degree of carbonation makes a difference as well, but I wonder if it would affect the number of bubbles, or the size of the bubbles more?

Also a great hypothesis, more nucleation sites would increase the number of bubbles not allowing large bubbles to form as frequently, and I would think carbonation levels are a contributing factor as well.

Put both of these hypothesis together and you have an extremely valid argument. Having said that, there are numerous variables involved such as filtration, carbonation levels, viscosity (protien content, dextrine content), who knows, even water chemistry may have some effect on the carbonation as well, even if at a very small level.

Bubble size can have an impact on the taste of the beer IMO, I happen to like beers that have many tiny bubbles, drinking the BMC swill from glasses do have those big bubbles especially from draft, and they do taste worse than normal from the draft rather than out of a bottle. Funny enough canned crap also seems to have much different carbonation than bottles, so maybe it is just carbonation level.

Does anyone know af any data where canned beer is carbonated to a lesser degree than bottles?

Intersting topic, anyone here really know the science behind gasses and how their pressure ( in volumes) would contribute to co2 bubble size given a beers type and style, bottled vs canned vs kegged?

 

[Shooter]

I believe it has to do with tiny demons living in the bottles. The big brewers have ways of keeping them out, but we homebrewers just have to deal with them. However, this is just a theory.

 

[remilard]

generally lower surface tension = larger bubbles. Water, soda and wine when carbonated all have large bubbles. Beer which has proteins, polyphenols and other things increasing surface tension have smaller bubbles.

Note that simethicone when added to beer (as fermcap) or taken internally (as gas-x) reduces surface tension which causes very large bubbles that are removed quickly.

I'd think more nucleation sites would cause more small bubbles to evolve initially but eventually I think surface tension dominates the equation as all those little bubbles will either join or not join based on surface tension.

 

[dorklord]

generally lower surface tension = larger bubbles. Water, soda and wine when carbonated all have large bubbles. Beer which has proteins, polyphenols and other things increasing surface tension have smaller bubbles.

Note that simethicone when added to beer (as fermcap) or taken internally (as gas-x) reduces surface tension which causes very large bubbles that are removed quickly.

I'd think more nucleation sites would cause more small bubbles to evolve initially but eventually I think surface tension dominates the equation as all those little bubbles will either join or not join based on surface tension.

I'm sure that the properties of the fluid (density, viscosity, surface tension, etc), the level of carbonation, and the availability of nucleation sites all make a difference. Although we tend to think of liquids as completely homogeneous, on a small scale, they aren't. At a given nucleation site, CO2 molecules are going to come out of solution and form a bubble. The amount of time that bubble clings to the nucleation site is going to depend largely on the properties of the fluid. The amount of CO2 that comes out of solution, into the bubble, is going to depend on the partial pressure of the CO2 in the solution. That, in turn, is dependent on nucleation sites, because the CO2 takes time (not much, but significant to the scale at hand) to diffuse from areas of high concentration (less nucleation sites) to low (more nucleation sites).

Of course, the properties of the fluid are going to affect bubble size not just because of how long the bubble clings to the nucleation site, but also more directly in relation to pressure. The bubble is basically inflating a balloon, where the skin of the balloon is the surface tension of the fluid. That level of surface tension, and the pressure of the surrounding fluid, is going to affect how much CO2 it takes to inflate the bubble to a given size.

I'm sure someone has written their master's thesis on this topic. Actually, they may have written the thesis on the whole diet coke and mentos thing, but the physics involved are applicable.

 

[Schnitzengiggle]

generally lower surface tension = larger bubbles. Water, soda and wine when carbonated all have large bubbles. Beer which has proteins, polyphenols and other things increasing surface tension have smaller bubbles.

Note that simethicone when added to beer (as fermcap) or taken internally (as gas-x) reduces surface tension which causes very large bubbles that are removed quickly.

I'd think more nucleation sites would cause more small bubbles to evolve initially but eventually I think surface tension dominates the equation as all those little bubbles will either join or not join based on surface tension.

What about champagne? Champagne seems to have lots of tiny/little bubbles, however once they reach the surface they turn quite large.

 

[dorklord]

What about champagne? Champagne seems to have lots of tiny/little bubbles, however once they reach the surface they turn quite large.

Bubbles in general should grow larger as they rise through the liquid, as the pressure being exerted on them drops. I can't imagine that the pressure drop is much, though.

 

[Pappers_]

I believe it has to do with tiny demons living in the bottles. The big brewers have ways of keeping them out, but we homebrewers just have to deal with them. However, this is just a theory.

Sometimes they talk to me . . .

 

[dorklord]

Sometimes they talk to me . . .

Drink me...

 

[Monster Mash]

A great way to experiment on your own is with carbonator caps.

I carbonate water, lemonade, apple juice, cranberry juice...ect and all of them have large effervescent bubbles. I pressurize to 30psi and shake the crap out of it. When I put beer into a bottle and force carbonate it does not produce the same effect, the bubbles are smaller and stay in solution better. The lighter, less alcoholic beers carbonate better then the darker higher gravity ones.

 

[Shooter]

Sometimes they talk to me . . .

Drink me...

Hmm, looks like scientific support if you ask me. I'll go ahead and write it up and submit "Shooter's Theory of Demonic Carbonation" to the scientific community. Nobel prize, here I come!