How keeving determines oenological parameters and concentration of volatile compounds in ciders?

Keeving consists in the removal of nutrients (which are yeast nutrients) from apple juice, due to their binding with pectin, and is dependent on the concentration of calcium ions. The aim of the study was to assess the effect of different yeast strains on oenological parameters and the profile of volatile cider compounds during the process of keeving. The experiments involved production of cider using different strains of yeast and different doses of CaCl2 in the keeving process. The basic oenological parameters of ciders and volatile compound profiles were evaluated. Keeving has been shown to slow the use of sugars by yeast and, as a result, lower alcohol levels in ciders. The concentration of FAN (free amino nitrogen) after keeving was significantly reduced compared to the control samples. Ciders made by keeving were characterized by higher concentrations of acetates and some terpenoids. In contrast, other volatile esters were present at lower concentrations.

Automated summary

Keeving is a process that involves removing yeast nutrients from apple juice by binding them with pectin, and it is influenced by the concentration of calcium ions. Research shows that Keeving can slow down yeast's use of sugars, leading to lower alcohol levels in ciders, and reduce the concentration of free amino nitrogen, resulting in ciders with higher concentrations of acetates and some terpenoids.