The effect of carboxymethyl cellulose and sucrose addition at dosage stage on the foam attributes of a bottle-fermented English sparkling wine.

Given the importance of foamability in sparkling wines, a significant body of research has been conducted in an attempt to further understand the processes underpinning foam formation, with a view to being able to improve foam production and bubble collar stability. Dosage is the penultimate stage of sparkling winemaking, and consists of topping up the bottles after disgorging by addition of wine and other products. A critical, yet understudied, area of research is the potential for dosage to influence foam behaviour. In this study, increasing levels of sucrose (from 0 to 31 g/L) or carboxymethyl cellulose (CMC) (from 0 to 100 mg/L) were added to a commercially produced sparkling wine at the dosage stage. The effect on the physiochemical wine characteristics, and therefore foam behavior, were analysed via an adapted Mosalux method and a novel image analysis method combined with free pour of the wine. Results indicate that increasing sucrose concentration improved foam formation, but reduced foam stability, likely due to the added sucrose causing a modification in wine viscosity. Conversely, CMC did not cause major changes on wine parameters, with the exception of wine viscosity, and did not result in major modification of the foamability of a wine. Practically speaking, these findings suggest that the more sucrose added at dosage, the greater the potential the wine has of quickly producing a high foam level after pouring when compared to a wine with no sugar added, whilst CMC could be added at the dosage stage without compromising the foam quality attributes of a wine. In general, these results highlight the impact that dosage treatments can have on the quality of foam produced upon pouring, and therefore have the potential to inform future sparkling winemaking practices.