Buzz: Hey, Marnie, I was just at the State Store and saw a bunch of red champagnes for Valentine's Day. Is that new?
Marnie: Sort of, Buzz. It's true that red sparkling wines have become more popular in recent years and are being sold in a wider range of styles. However, they're not exactly an innovation. For example, Italian Lambrusco was pretty popular in the '70s. Remember the commercials for Riunite — "So nice on ice?" Typically, these are usually sweet as well as bubbly, but drier versions are available now, too.
Buzz: Oh, yeah. I always figured that stuff was just spiked grape soda.
Marnie: Sort of, but not in the way you might think. Sparkling wines are not sweetened and carbonated the way today's sodas are. They don't need to be, because bubbles are a natural byproduct of fermentation. When yeast cultures consume grape sugar and metabolize it into alcohol, the process generates carbon dioxide gas. That means that if you taste any wine halfway through its fermentation, it will always taste sweet and be carbonated.
Buzz: But how come all champagnes aren't sweet, then?
Marnie: For the same reasons that most wines aren't sweet — it's far more practical for vintners to make their wines taste dry, or not sweet. Dry wines are easier to make, because interrupting fermentation midstream is complicated. They're also easier to store and to sell, since high levels of sugar make wines prone to spoilage, requiring preservatives to avoid refermentation in the bottles.
Buzz: But didn't you just say that sweet sparkling red wines are getting popular?
Marnie: Yes. The vast majority of wines are still, not carbonated, and dry, not sweet. But the sparkling wines that have sweetness taste pretty darned good, so they're growing more popular now that modern technology allows us to bottle them safely. And while most of these are white or pink, more red versions are showing up on shelves — from sweeter red moscatos and brachettos to drier red styles, like Australia's sparkling Shiraz — just in time for Valentine's Day.