|Egg whites may be used to "fine" wine.|
In looking into organic wines last week, I was reminded of something else that’s relevant to a large group of wine drinkers – vegetarians and vegans. While not fitting into either category myself – I love a good steak here and there – I don’t often think about the peripheral products used to make the wines I drink, but to many of my vegetarian and vegan friends, as well as those with certain food allergies, knowing this can be enlightening. If you’re not informed about how wine is processed, you may not even know that wineries often use animal-based products during vinification.
The primary use of these products, and I’ll list them shortly, is as “fining agents.” Fining is the process by which tiny, sometimes microscopic particles are removed from the wine to make it, for instance, less harsh to the taste or hazy or cloudy in appearance. Fining should not be confused with “filtering,” which removes larger particles like excess yeast at the end of the fermentation process, just before bottling.
Fining usually takes place earlier in the process, and helps speed up what would eventually happen naturally. The microscopic particles that fining removes are comprised of things like tannins and proteins (called unstable colloids). When fining agents are added to the wine, they clump together with the colloids and drop to the bottom of the vessel, where they form a sediment that the winemaker can easily remove.
Generally, white wines are fined to preserve their lighter color and to prevent cloudiness in the wine; red wines are fined to reduce their astringency and the bitterness of tannins, which come from the skin and stems of the grapes.
Because fining can stabilize wines, it is almost universally practiced, however, some makers of fine (in this case meaning “better”) wines do not, believing that it can interfere with the flavor of their wine.
Some of the organic fining agents that may be used are:
Gelatin: This is the same gelatin found in products like jelly and Jell-O, and it comes from beef bones. Small amounts of it remain in the wine after fining (although some would argue that no trace is left).
Isinglass: This is a protein obtained from the bladders of sturgeon and other freshwater fish, and which has been used for centuries to fine wine.
Egg whites: The albumin in the egg whites creates an effective filter, particularly for red wines, where it absorbs harsh and bitter tannins.
Casein: A milk protein, this fining agent is principally used to remove the brown color from white wines.
Blood Powder: Historically, dried bull’s or other bovine blood was used to filter wine. This is rarely if ever used in current-day winemaking.
More and more winemakers are aware of and sensitive to the growing ranks of vegans, vegetarians, and allergic wine drinkers, so they use a variety of inorganic fining agents. Various kinds of clay are used, including bentonite (the most used and most effective), silica, and kaolin. Other possible fining agents are charcoal (to remove brown and other off-colors) and potassium ferroocyanide (to remove copper and iron).
Be aware that wine labels in the US and Europe do not require the listing of fining agents that are considered allergic substances, such as egg whites, but wines made in Australia and New Zealand do require it.
If in doubt when buying wine, talk to your wine merchant, who should be able to steer you toward wines that are good for you. Or, do your own research. Many of the details of the winemaking process are available on winemakers’ Web sites. And, finally, if ever in doubt, contact the winery directly. They’re a friendly lot, in my experience, and will give it to you straight.
Until next time, cheers!