The quality of the grapes is a determining factor in the proper conduct of alcoholic fermentation and in obtaining stable, balanced, and aromatically complex wines. Healthy grapes guarantee regular yeast metabolism, complete fermentation, and optimal enhancement of phenolic and aromatic compounds.
When grapes are partially rotten or damaged by hail, their chemical and microbiological composition changes profoundly, with direct consequences on fermentation. Damage to the berries facilitates the entry of unwanted microorganisms and the onset of premature oxidation, leading to changes in pH, a reduction in titratable acidity, and the degradation of aromatic and phenolic compounds.
The result is a less balanced must, more susceptible to the proliferation of unwanted yeasts and bacteria and potentially subject to sensory alterations in the final wine. Under these conditions, even standard winemaking practices may be less effective, requiring targeted interventions to preserve product quality.
Impact of unwanted microflora
Damaged grapes provide an ideal environment for the development of moulds, apiculate yeasts and lactic or acetic bacteria. Among these, Botrytis cinerea plays a particularly critical role. This fungus produces laccase, an oxidative enzyme that degrades anthocyanins and tannins, reducing the colour stability and phenolic structure of the wine.
Competition between unwanted microflora and selected Saccharomyces cerevisiae yeasts can slow down fermentation, make it irregular or, in severe cases, cause it to stop. The combined effect of laccase and microbial proliferation can compromise not only the sensory quality but also the shelf life of the wine.
Gluconic acid: a key indicator of grape health
A key parameter for assessing the extent of damage is gluconic acid. This compound is formed when fungi such as Botrytis transform glucose through the enzyme glucose oxidase.
Gluconic acid values provide immediate information on the degree of fungal infection:
- in musts obtained from healthy grapes, levels generally remain below 0.2 g/L
- in the presence of compromised grapes, they can exceed 1–2 g/L
- in the most severe cases, values can exceed 5 g/L
Monitoring gluconic acid allows you to estimate the risk of problematic fermentation and plan targeted interventions to reduce the negative effects on the wine.
Essezym Beta: our solution
To address these critical issues, we offer Essezym Beta, an enzyme preparation based on fungal beta-glucanase. This product acts specifically on the cell walls of fungi, helping to release aromas and polyphenols without laccase degrading pigments or accelerating oxidative processes.
The main characteristics of Essezym Beta include:
- beta-1,3- and beta-1,6-glucanase activity, to degrade the polysaccharides in the cell walls of fungi
- basic proteolytic activity, useful for improving the extraction of noble compounds present in grapes
- ability to preserve the color, structure, and stability of wine, even in musts obtained from compromised grapes
Thanks to this strategy, it is possible to effectively manage the risks associated with damaged grapes, ensuring more regular fermentation, more balanced wines, and greater enhancement of organoleptic characteristics. The integrated approach of monitoring and enzymatic intervention is now an advanced solution for wineries that want to ensure quality even in particularly critical vintages.