Layers of macromolecules at the champagne/air interface and the stability of champagne bubbles

Adsorption layers formed at the air/degassed champagne interface were chara cterized by ellipsometry and by surface tension measurements of the samples diluted four times with water. Ultrafiltration of the samples showed that the adsorption layer is mainly formed by macromolecules with molecular mass es in the range 10(4) to 10(5). Nonsparkling base wine was ultrafiltrated w ith a molecular mass Cutoff of 10(4), and the resulting ultraconcentrate an d ultrafiltrate were combined to yield experimental base wines with adjuste d macromolecular content. These samples were submitted to bottle fermentati on. The resulting experimental champagnes were tested for the extent of the ir bubble collar and for their surface properties. A good correlation was f ound between the two sets of data.