<P> Beer head ( also head or collar ) , is the frothy foam on top of beer which is produced by bubbles of gas , typically carbon dioxide , rising to the surface . The elements that produce the head are wort protein , yeast and hop residue . The carbon dioxide that forms the bubbles in the head is produced during fermentation . The carbonation can occur before or after bottling the beer . If the beer continues fermenting in the bottle , then it naturally carbonates and the head is formed upon opening and / or pouring the beer . If the beer is pasteurized or filtered then the beer must be force carbonated using pressurized gas . </P>
<P> Beer head ( also head or collar ) , is the frothy foam on top of beer which is produced by bubbles of gas , typically carbon dioxide , rising to the surface . The elements that produce the head are wort protein , yeast and hop residue . The carbon dioxide that forms the bubbles in the head is produced during fermentation . The carbonation can occur before or after bottling the beer . If the beer continues fermenting in the bottle , then it naturally carbonates and the head is formed upon opening and / or pouring the beer . If the beer is pasteurized or filtered then the beer must be force carbonated using pressurized gas . </P>
where does the carbonation in beer come from
where does the carbonation in beer come from
wort protein yeast hop residue
wort protein yeast hop residue