Everything you need to know about dimethyl dicarbonate or DMDC (E242)

dans le vin

Discover DMDC, a compound that preserves the flavour of wine while preventing refermentation and the development of unwanted microorganisms.

In the world of oenology and beverages, dimethyl dicarbonate plays an important role. Better known by its abbreviation DMDC, this synthetic compound preserves the sensory qualities of liquids, while eliminating any risk of refermentation and the development of unwanted microorganisms. Get to know DMDC better with five key questions (and answers!) about wine and DMDC.

What is DMDC?

DMDC is a synthetic compound, derived by synthesis. What is synthesis? It is a series of reactions brought about to produce a final product, in this case dimethyl dicarbonate.

This particular product is used as a preservative. It thus belongs to the family of wine preservatives and antioxidants, which includes sulphites, potassium sorbate (E202), L-ascorbic acid (E300) and lysozyme (E1105).

What is dimethyl dicarbonate used for in wine?

Having bought your precious bottle of white, red or rosé wine, you wouldn’t be happy if bubbles started forming in it while it was stored in your cellar, would you? And that’s understandable!

This is precisely why DMDC is so important. This winemaking ingredient prevents any risk of unwanted refermentation after bottling, whether alcoholic or malolactic. This property of DMDC makes it especially useful for sweet wines (mellow, sweet and syrupy), as these contain more residual sugar than dry wines.

This same property also makes DMDC a good alternative to pasteurisation, which becomes less necessary for preventing fermentation not only in wines but also in other drinks containing residual sugars, such as certain ciders.

Lastly, this oenological product conserves wine without affecting its flavour. In other words, it stabilises the product without affecting its taste or leaving any residue, as it breaks down quickly after use.

How does DMDC work in wine?

In practical terms, when used in winemaking, DMDC prevents refermentation by eliminating yeasts. It controls populations of unwelcome microorganisms (including yeasts and lactic acid bacteria) by inactivating their cells, which halts their reproduction and growth.

How is this preservative used in winemaking?

If your wine label tells you that dimethyl dicarbonate is an ingredient in your sweet white wine, then it has probably been added after alcoholic fermentation (otherwise DMDC would stop the vital fermentation process, which allows the grape must to transform into wine!).

However, DMDC is sometimes added to the wine a little later, before bottling. In both cases, the winemaker or the winery teams always use a meticulously precise dosage suited to the profile of the wine.

Besides the wine sector, where else is dimethyl dicarbonate used?

DMDC is a popular additive in the drinks industry, not just for wine but also for fruit juices and soft drinks.

After reading the answers to these five key questions – questions you may already have been asking – you now understand the precise link between wine and DMDC. As with every oenological product used with care by the winemaker, dimethyl dicarbonate serves above all to enhance the quality of your final tasting experience. That’s the science of making good wine!