Why does beer carbonation seem different from soda carbonation?
Beer is naturally carbonated (production of CO2 from yeast when it turns sugars into ethanol) (also some CO2 may be added) which can produce smaller bubbles while soda is 100% added CO2.
Soda is generally more carbonated than any beer. Beer actually has a variety of carbonation strengths depending on the style and brewer’s preference, but these will all be less than a soda. The process for force carbonating both is slightly different but doesn’t matter as much as that soda is simply more higher carbonation.
Additionally the beer you get depending on if its draft or bottle/can may be carbonated a bit differently. Bottle/can comes direct from the manufacturer, but also may lose some carbonation over time (but it takes a while). When you get a beer on draft, the bar has a system setup to keep beers carbonated, but these systems aren’t always in perfect working order, and some beers “should” be served at specific co2 levels, but most bars don’t have the complex setups needed to serve many beers all at different levels– go to a very nice craft beer spot though and they just may.
A very limited amount of beers are carbonated in the bottle vs. force carbonation. These beers have less predictable carbonation levels due to lots of factors, but these beers are not the common beers you have. Nearly every beer you drink is not bottle conditioned. This is a more difficult, less precise, expensive, and time consuming process, so its used far less often
Soda will have a very “effervescent” carbonation (that means lots of bubbles) while beer generally with a lower carbonation is much less pronounced, outside of some specific styles.
Beer* has protein. Protein gives the foam a way stronger structure making it stay further and I think also allows the foam to keep more flavor.
Edit: That was an interesting misspell..
The key word is **surfactants** – the compounds in the carbonated water that change the surface tension and are responsible for ease of foaming and foam stability.
Beer (as has been pointed out) has proteins that stabilize small bubbles, leading to a foamy head. Soda also contains surfactants, but they are generally not as stable, so you don’t get long-lasting foams.
Some beers (Guinness, and similar beers) are not carbonated, but are pressurised with Nitrogen. Nitrogen forms extremely small bubbles, and the high surfactant content of these beers leads to a very stable foam.
Beer contains more proteins than soda does. That’s the stuff the bubbles consist of, along with water.