Q: Awhile back I noticed the TTB approval of Dimethyl Dicarbonate (DMDC) as a processing aid in beer production, but I haven't seen anything more written about it. Can you tell me a little about this option? The TTB release describes it as a "microbial load reducer" and I can find a number of resources that cite its use in winemaking. They seem to use it to reduce wild yeasts. Does DMDC have any effect on beer-spoiling bacteria? Is this a product we'll see beer suppliers carrying in the near future? An overview of processing instructions or help identifying further resources might be useful as well.
A: The commercial name is Velcorin and it has been used in soft drinks and wines (usually low alcohol sweet wines with some residual sugars) for some time, mostly in South America and South Africa. It has recently been approved for use in both wine and beer in the US and at least one large US winery is studying its use in sweet, low alcohol wines. Velcorin is effective against yeast, bacteria and molds. It penetrates the cell membrane and targets certain enzymes which results in the cells lysing (opening up) and re-fermentation is almost impossible. You can find out more at www.velcorin.com