Wine spoilage can occur if we don’tt take care of the different stages that need to happen to make wine.

 

By Alejandra Aguilar, Ph.D./Todos Santos

 

2007-0210-2

Photo: LEXESS.COM

In my previous columns, I have talked about two different yeasts: Saccharomyces cerevisiae and Brettanomyces bruxellensis. As you may recall, S. cerevisiae is the main yeast that is used to make wine, however S. cerevisiae is also considered a wine spoilage yeast due to if it is present in finished wine that has been bottled can cause a refermentation. On the other hand, B. bruxellensis is usually considered a disgrace in the wine world, due the off aromas that can produce, especially in red wine. However, this will depend on the levels produced of these off aromas. Furthermore, Zygosaccharomyces bailii is another yeast non desirable in wine due to its resistance to certain antimicrobials used in wine industry. Different effects on wine can be observed due to the presence of certain yeasts, bacteria and molds, some of them are summarized in Table 1. 

As you might have realized, wine is not free from microbial contamination and thus cleaning and sanitation in your winery is as important as the use of the best winemaking protocols as well as the quality of your fruit. However, besides of all the above mentioned, we can increase the microbial safety of our wine with the use of certain compounds, such as the use of a wine sterilant.

DMDC (Dimethyl dicarbonate) or Velcorin™ is a very common additive in wine industry and it has been used in USA since 1988. While primarily used as a yeast inhibitor (FDA approved), DMDC also shows inhibitory activity against other microorganisms such as molds and bacteria (Basaran Akgul et al. 2009). DMDC is a wine sterilant used especially before bottling. Its use in Mexico for wine industry is relatively new (personal communication).DMDC it is used at a maximum permitted concentration of 200 mg/L (ppm).

Table 1. Effect of the presence of some common wine spoilage microorganisms

Yeast

Effect on Wine

Zygosaccharomyces bailii

Haziness, refermentation in bottle (this mainly occurs in sweet wines with the concomitant production of carbon dioxide causing the explosion of the bottle)

Saccharomyces cerevisiae

Haziness, refermentation in bottled sweet wines

Brettanomyces bruxellensis

Off-aromas

Bacteria

Effect on Wine

Lactic Acid Bacteria that could include: Lactobacillus brevis and Lactobacillus buchneri

Bitterness taint

Molds

Effect on Wine

Botrytis cinerea (responsible for fruit rot)

Production of the oxidative enzyme “laccase”, which in the presence of oxygen can cause oxidative spoilage and a moldy character in wine.

One of the advantages of the use of DMDC is that, it suffers a rapid degradation once is dosified in wine and it does not affect taste, color or aroma. Its degradation is usually in few hours and the products of its degradation are negligible amounts of methanol and carbon dioxide. In wine industry, it is applied using a dosing machine that guarantees the right dose and the safety of the winery staff, due to DMDC can be irritant to skin and eyes and toxic if it is inhaled or ingested. Lanxess, the manufacturer of Velcorin™, has recently released a new generation of dosing technology, “Velcorin™ DT Touch” which is currently marketed worldwide for the filling of Velcorin™ as a cold sterilization agent in non-alcoholic beverages and wine (www.velcorin.com).

My recommendation is to use DMDC as an extra aid in your winery, since cleaning and sanitation practices must also comply with high standards. This will create consistency and excellent reputation for your wine year after year. In my next columns, I am going to talk about different sanitation practices that you can apply in your winery.

 

References

  • Basaran Akgul N., J.J. Churey, P. Basaran and R.W. Worobo. 2009. Inactivation of different strains of Escherichia coli O157:H7 in various apple ciders treated with dimethyl dicarbonate (DMDC) and sulfur dioxide (SO2) as an alternative method. Food Microbiol. 26:8–15.

  • As found on the LANXESS website (www.velcorin.com)

 

Alejandra Aguilar can be contacted at [email protected]