Enzymes Can Improve Wine Quality
Applies to: Winemakers looking to increase color extraction and enhance structure, increase aromas, or improve wine roundness. This article details which enzyme activities are suitable for each goal.
Enzymes Can Improve Wine Color and Structure
By Increasing Anthocyanin and Tannin Extraction in Reds
The extraction and stabilization of color and structure molecules in red wines is a complex topic, but we do know that enzymes can play a role in improving both of these. Anthocyanins are the main compounds responsible for color in red wines. Anthocyanins are extracted from grape skins during fermentation and are color-active depending on pH but are not inherently stable on their own. Their long-term stability in wine depends on their ability to form complexes with larger molecules (like tannins). Enzymes can help increase color and color stability by increasing extraction of both anthocyanin and tannin*. While important in color stability and complexing, tannins are also a major contributor to wine structure.
Anthocyanins and tannins located within the grape skins can be released with certain enzymes, known as macerating enzymes. These enzymes degrade grape skin cell walls and will facilitate the release of both compounds. Macerating enzymes specifically include those with cellulase and hemicellulase side-activities which break down cellulose and other structural polysaccharides1.
Enzyme preparations for color extraction and stabilization often have a mix of enzymatic activities. The way these enzyme activities work together is synergistic, not purely additive, such that gentle extraction can be achieved without overextraction. Overextraction can lead to bitterness, astringency, and harsh phenolics.
*It is worth noting that beyond concentration of anthocyanin and tannin, there are other factors that affect the success of forming stable anthocyanin complexes.
Enzymes Can Improve Wine Aroma
By Increasing Varietal Compounds
Aroma compounds are found in grape skins and the pectin layer immediately beneath the skins. Aroma compounds are either free (odor-active) or bound (odorless). Both types are extracted into juice via skin contact and/or pressing. Enzymes can help increase extraction of both free and bound aroma compounds and can also convert bound aromas into free aromas. Pectinases with β-glycosidase activity are well-suited to achieving both goals and can be used at multiple stages of the winemaking process.
Pectinases are useful as pre-pressing, skin contact enzymes. They gently break down skins and the pectin layer, allowing more aroma compounds to be extracted during pressing. This action releases many types of free and bound aromas including terpenes, thiols, and norisoprenoids. Collectively, these compounds contribute to fruity, floral, citrusy, and spicy aromas that are part of a grape’s varietal character.
β-glycosidase enzymes act upon bound aroma compounds which are odorless, converting them into the odor-active, free form. Specifically, terpenes and norisoprenoids are bound to sugars and can be released by β-glycosidase enzymes2. This action is inhibited if glucose is > 50 g/L, so they work best after fermentation. Bound terpenes exist at much higher concentrations than free terpenes, so releasing them helps maximize the aromatic potential of the grape.
It is important to note that β-glycosidase activity will continue until inhibited (with a bentonite addition). These enzymes should be bench trialed or the wines closely monitored to determine the appropriate amount of enzyme action.
Enzymes Can Improve Wine Texture
By Increasing Wine Roundness
Polysaccharides are a class of molecules that broadly correlate to wine texture. Beneficial polysaccharides can be released into wine when yeast die and autolyze (break down). Thus, lees aging often leads to rounder, fuller-bodied wines. β-glucanase enzymes will break down yeast cell walls, allowing faster release of polysaccharides which adds mid-palate and boosts mouthfeel. Further degradation of the yeast will also lead to release of peptides and nucleotides, which can increase savory or sweet characters. β-glucanases can also assist with filtration problems, particularly those related to Botrytis infection (See Enzymes Can Make Filtration Easier).
See the buying guide below for assistance in selecting Scott Labs enzymes to improve wine color, aroma, and texture.
|Increase Color and Structure||These enzymes should be added to red fruit pre-fermentation and/or during fermentation.|
|These enzymes should be added directly to grapes (skin contact), or after fermentation has completed (post-fermentation).|
|Improve Wine Roundness|
MMX contains β-glucanase derived from Trichoderma harzianum which is listed in 27 CFR 24.250.
|MMX should be added near the end or right after fermentation but at least 4-8 weeks before bottle preparation. In order to maximize benefit of LALLZYME MMX, a contact time of 6-8 weeks is recommended.|
- Mojsov, K., Andronikov, D., Janevski, A., Jordeva, S., & Zezova, S. (2015). Enzymes and wine: The enhanced quality and yield. Savremene Tehnologije, 4(1), 94–100. https://doi.org/10.5937/savteh1501094m
- Liu, J., Zhu, X.-L., Ullah, N., & Tao, Y.-S. (2017). Aroma glycosides in grapes and wine. Journal of Food Science, 82(2), 248–259. https://doi.org/10.1111/1750-3841.13598