Hey there, time traveller!
This article was published 14/9/2012 (1717 days ago), so information in it may no longer be current.
WE all know wine is fermented grape juice, right?
Yes, wine is made from boozy grapes -- just over a kilogram of fruit per bottle, in fact -- but there's also plenty of other stuff you may not have known about in the mix, as well as various things that have touched the wine in your favourite bottle.
So what else is in there? Plenty, as it turns out...
To make wine, grape juice must be fermented, and to convert sugar to alcohol, yeast is needed. Fermenting grapes/grape juice produces its own wild yeasts, but more often than not a cultured yeast is added to a wine to foster fermentation. Cultured yeast yields more predictable results than wild yeasts, and anything that fosters predictable results means less of a headache for winemakers.
The naturally occurring sugar (fructose and glucose, specifically) in grapes is what ferments into ethanol and carbon dioxide. If a winemaker feels grapes are slightly underripe and/or is looking to extend the fermentation process to increase alcohol content, sugar is added in a process called chaptalization or enrichment. It's a practice more common in cooler wine-producing regions.
If a vintage gets quite hot or grapes get a touch overripe, the grapes bring an abundance of sugar and very little acidity. In order to keep the wine's structure a little more lively and lean, some winemakers will acidify a wine to retain a sense of freshness. This is especially common in warmer wine-producing countries, as the grapes get quite ripe and the wine is in need a bit of vibrancy and structure. Tartaric acid is the most commonly added acid.
Like yeast, sugar and acid, sulfites are naturally occurring in wine. White wines, especially sweeter ones, have higher levels of sulfites than a dry red wine. Many winemakers add also sulfur dioxide as a preservative and stabilizer for the wine's journey from the vineyard to your local shop.
OK, oak doesn't exactly go into a wine -- rather, it's commonly the other way around. But some wineries looking to avoid buying costly barrels add oak chips to wine during fermentation, or will place oak staves in a fermentation tank to impart the wood's signature vanilla and spice notes. Oak chips and staves bring flavours similar to oak aging -- albeit slightly less complex -- at a fraction of the price.
Oak barrels let in minute amounts of oxygen, helping a wine develop complexity before bottling. But a process called micro-oxygenation allows winemakers to inject wine with oxygen and mimic the oak aging process. Combined with oak chips/staves, it can add depth and complexity to a wine while, again, saving the winemaker from buying pricey barrels.
Yes, fish bladders. While rare these days, a protein from the bladder of freshwater fish (especially sturgeon) called isinglass is sometimes used in the process of making sure a wine isn't cloudy (a process called fining).
Like isinglass, egg whites have traditionally been used in the fining process. And, like isinglass, the use of egg whites is increasingly rare, as winemakers have turned to minerals like bentonite and charcoal for the fining process, making most wines vegetarian/vegan-friendly.
RUDOLF MÜLLER 2011 "RABBIT" RIESLING (Pfalz, Germany -- around $11, private wine stores)
Red apple, peach, perfume and lemon candy aromas show well on the nose of this German white. It's off-dry, and delivers beautiful peach and sweet apple flavours with a splash of acidity for balance. Try this with sushi or mild to medium Asian fare -- it's a great value. Sampled at the Fenton's Wine Merchants booth at ManyFest. 87/100
TESCH 2009 RIESLING UNPLUGGED (Nahe, Germany -- $16.99, Liquor Marts and beyond)
"Unplugged" refers more to the winemaking philosophy than music here (after all, I'm told Martin Tesch likes to blast punk rock in his cellars to help the wines along -- very cool). There's minimal winemaking intervention on this wine, and the result is, ironically, electric. Bright honey, lemon, red apple and mineral notes on the nose precede a vibrant, light-bodied and crisp white on the palate. Red apple and lemon rind notes are snappy, and a bit of bottle age has added depth and complexity here. Fantastic. 90/100
WYNDHAM ESTATE 2011 BIN 222 CHARDONNAY (South Eastern Australia -- $14.99, Liquor Marts and beyond)
Medium gold in colour, the Bin 222 offers honey, perfume, melon, mango and a hint of smoke on the nose. It's a medium-bodied Chardonnay that offers those same notes on the palate as well as peach and apricot and a hint of vanilla. Interestingly, the winery's data sheet notes "French oak maturation" but doesn't specify actual barrels -- could they have used French oak chips/staves? Regardless, it's a very good Chardonnay. 88/100