The yeast Brettanomyces bruxellensis is the most important wines spoilage yeast encountered during winemaking as it can survive in wine for long periods, requires minimal nutrients for growth, and can be difficult to control. Brettanomyces produces two major spoilage products, the volatile phenols 4-ethylphenol (Band-Aid, medicinal smell) and 4-ethylguaiacol (smoke,...
Malolactic fermentation (MLF) is important in the production of wines as it reduces acidity through the conversion of malic acid to lactic acid. However, successful MLF can be difficult to achieve due to yeast antagonism of the bacterium responsible for
the secondary fermentation, Oenococcus oeni. In particular, yeast produced sulfur...
Commercial vats of Chardonnay and Pinot Noir were
inoculated during yeast fermentation with starter cultures
containing 10⁷ - 10⁹ cfu/ml of the malolactic bacteria
Leuconostoc oenos Erla and Ey2d in lots ranging from 55 to
4,000 gallons. Chardonnay inoculated with Ey2d completed
MLF in an average of 56 days at...
Gram positive cocci isolated from Oregon wines
were characterized and their relative malate fermentation
abilities compared. They were heterofermentative,
catalase negative, and facultatively anaerobic. Glucose,
fructose, cellobiose, maltose, ribose, trehalose, salicin
and esculin were fermented by all strains. Arabinose was
fermented weakly but lactose, raffinose, sucrose, xylose,
rhamnose, mannose and...
Lactic streptococcal agglutinins are known to promote settling of starter bacteria in milk, resulting in spongy, mealy, shattered curd and sludge formation defects in cottage cheese. These agglutinins are natural antibodies secreted by lactating cows in mature milk in response to infections (mastitis) and in colostrum milk as protective antibodies...
High hydrostatic pressure (HHP) affects the pH of weak acids due to an increased degree of acid dissociation while under pressure. The temporary pH reduction by high pressure in such a case may influence the barotolerance of microorganisms. The objective of this study was to determine the impact of weak...