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Aglycones can be released from glycosides by either exposure to acid (generally pH of 3 or lower, and different pH's giving different results on which glycosides are broken down; this breakdown of glycosides under low pH has been linked to the slow flavor development of aging wine <ref name="Maicas"></ref>), or by enzymes called beta-glycosidases. Enzymatic breakdown of glycosides as been described as producing a more "natural" flavor in wines versus acidic breakdown. Some fruits have been observed (mostly wine grapes) to have limited beta-glucosidase activity within themselves, however it has been observed as being unstable and having low activity at the low pH of wine and sour beer <ref name="Maicas"></ref>.
Beta-glycosidase enzymes can be added artificially, however there has been much interest in the natural capability of microorganisms to produce beta-glycosidases , particularly 1,4-β-glucosidase <ref name="Winterhalter"></ref>. Microorganisms that can break down glycosides by using beta-glucosidases can then access the resulting sugars for fermentation <ref name="Steensels"></ref>. There are two major categories of glucosidase activity: endogenous and exogenous. Endogenous enzymatic activity takes place inside of the cell, and exogenous enzymatic activity takes place outside of the cell. Bacteria and fungi that show endogenous glucosidase activity have been shown not to be effective in alcoholic fermentation due to not tolerating low pH (optimum pH of 5), glucose, and/or ethanol. Generally, the flavorless glycosides remain unaffected by yeast fermentation, leaving them unused as a potential source for flavor and aroma <ref name="Winterhalter"></ref>.
Exogenous beta-glycosidase activity has been shown to be much more effective at releasing aglycones from glycosides in bacteria and fungi. For glycosides which contain a glucose, which is the majority, beta-glucosidase cleaves the sugar, thus releasing the aglycone. For glycosides that contain disaccharides, usually another enzyme must be present to first break down the disaccharide before the beta-glucosidase can release the aglycone (beta-xylosidase, alpha-arabinosidase, alpha-rhamnosidase, or beta-apiosidase) <ref name="Winterhalter"></ref>. However, glycosides in tea leaves that contain disaccharide sugars (cellulose/cellobiose <ref name="ucdavis_chemwiki"></ref>) have been observed to be broken down without the use of these other enzymes; the beta-glucosidase cleaves the aglycone from the disaccharide on its own. Some species of yeast (''Debaryomyces castelli'', ''D. hansenii'', ''D. polymorphus'', ''Kloeckera apiculata'', ''Hansenula anomala'', and ''Brettanomyces'' spp), bacteria (''Oenococcus oeni''), and fungi (''Aspergillus niger'') have been found to have strain dependent beta-glucosidase activity, however several inhibitors for glucosidase activity vary for different strains of microbes. These inhibitors include the presence of glucose, pH, temperature, ethanol, and phenols <ref name="Maicas"></ref><ref name="Mansfield">[https://theses.lib.vt.edu/theses/available/etd-07262001-172630/unrestricted/Mansfieldthesis.pdf Quantification of Glycosidase Activities in Selected Strains of Brettanomyces bruxellensis and Oenococcus oeni. A. K. Mansfield, B. W. Zoecklein and R. S. Whiton. 2001.]</ref>. For example, for some strains of ''O. oeni'', as little as 10mg/L of glucose is enough to inhibit beta-glucosidase activity, or the presence of alcohol or typical wine pH (3.0 - 4.0) was enough to inhibit. Other strains of ''O. oeni'' are not inhibited by some or all of these inhibitors <ref>[http://www.sciencedirect.com/science/article/pii/S0168160505003296 A survey of glycosidase activities of commercial wine strains of Oenococcus oeni. Antonio Grimaldi, Eveline Bartowsky, Vladimir Jiranek. 2005.]</ref>.