Casein (from milk): To reduce oaky flavor in some whites, as well as decolor some hazy whites; can also be used to pre-fine the haze from moldy grapes during the juice stage
Gelatin: For astringent wines, mostly whites, but also some hardier, tannic reds
Bentonite: For older reds (you should be careful as over-fining can strip flavor)
Isinglass (from sturgeon bladders): For young whites
There’s nothing like combining egg whites with a strong, tannic red to bring out the wine's rounded flavor. We’re not talking about some kind of brunch wine pairing—we mean using egg whites during the winemaking process.
Think of it as consommé for winemakers. The albumin from the egg whites, which are poured into the barrels and allowed to sit, pull out harsh tannins and hazy impurities (often called the "casse"). After a bit of frothy mess, a more well-balanced wine is born. Depending on how dry or cloudy a winemaker wants a vintage to be, he might use other agents: sturgeon bladders, ground up crab shell, or even (until recently) blood. But for most tannic wines, egg whites are the go-to product.
However, the labor-intensive process of fining in this way turns off many winemakers, many of whom prefer bentonite clay filters. "It’s a lot of work," says John Kolasa, winemaker at Chateau Rauzan-Ségla, in southwestern France. "It’s a long process," he says, "but we make wine that’s going to be kept 20 to 50 years or more. We want to stay as natural as possible, so we do it [with egg whites]. We do it the old way."
Clarifying with egg whites doesn't necessarily have to take a long time. Jim Klein, winemaker at Navarro Vineyards in Philo, California, uses egg whites for several of his reds, including their 2007 Syrah and some of the Reserve Pinot Noirs. When he can, he’ll use chicken eggs from the onsite ranch (how's that for terroir?)—or, if he’s lucky, goose eggs—saying that other filtration methods can strip away too much of a wine’s mouthfeel and complexity. "At the end of the day, I feel like I’m a craftsman, and fining is a part of my craft," he says. "I look at unfined, unfiltered wines as I would unfinished furniture. They are certainly functional, but they could be that much more beautiful if polishes were used."
There Won’t Be Blood
For years in France’s Bourdeaux and Rhône Valley regions, ox blood was a venerated part of certain winemakers’ heritage. Not so anymore, at least not legally.
For years, the U.S. has outlawed the practice of blood-fining, and even the French turned away from it in 1997 when the European Economic Council banned the process after a rash of mad cow disease outbreaks. The oeno-boogeyman has continued to rear its blood-streaked head, however. In the early 2000s, some U.S. lawmakers unsuccessfully lobbied to require French winemakers to disclose their bloody production history. And in 1999, French authorities raided a dozen small Rhône wineries, confiscating hundreds of pounds of dried ox blood and nearly 100,000 bottles of wine.
Egg white fining is more common, but even that process has some oenophiles scared. Some countries, including New Zealand, require winemakers to label when their products use egg white fining, even though no studies to date have definitively found any allergen agent traces in such cases. According to Kay Bogart, program director at VENSource, a wine outreach program at the University of California-Davis, it all depends on the clarification and filtration regimes used at the winery. But the verdict is still out on allergen concerns. "There could, realistically, be residual albumin left in a bottled wine," she warns.
Some vintners are still leery of using real egg whites, though, preferring instead synthetic compounds. "Real egg whites are probably very rarely used," said Éric Texier, a winemaker in the Rhone Valley. "Why take the risk of a bad egg when you can buy refined albumin?"
It gets even trickier with vegans. Banning blood is one thing, but many other fining compounds are animal-based (gelatin from pigs, chitin from crab shells, casein from milk, isinglass from sturgeon bladders). To satisfy the non-carnivorous, winemaking vendors such as Scott Laboratories now offer other non-animal-based agents such as seaweed-derived alginates.
As disclosure isn’t required, some (like Navarro) do so proactively. "I have allergies, and I totally get what it is to have allergies and putting consumer information out there … though I haven’t seen anybody have adverse reactions [from wine]," Klein said. Besides egg whites, he also uses confectioners’ gelatin, which is made from pork belly, to fine some of his white wines. "We’re open and honest about what we do."
Egg White Fining Technique
1. Separate 2 to 4 egg yolks from the whites and place the whites in a bowl. Add a pinch of salt and about a pint of water. This solution is for a 60-gallon barrel of wine.
2. Gently whisk the whites, but do not beat them. Pour the mixture into the wine and stir gently for about 1 minute.
3. Let the mixture sit in the wine for about a week. This depends on the type of wine and how much mouthfeel you want to retain and the flavor you wish to impart (Klein lets his whites sit for about 3 to 10 days; Kolasa allows fining to occur over 6 or 7 weeks). The initial reaction will probably take place within 24 hours.
4. Inspect the wine after 4 days, looking for clarity about 1 or 2 feet above the surface. Leaving the egg whites in too long can over-fine and strip the wine.
5. Once you are satisfied the wine has been adequately fined, rack the wine carefully into another barrel, drawing out the whites and remaining sediment (use a candlelight to look for and prevent any solids from making it into the second barrel, if possible). Discard the gunk at the bottom (or use it to make the worst scrambled eggs ever).