Since the majority of persons that are celiac or gluten sensitive is allergic to the milk protein casein, I have to report that those people may react to red wine. It appears that casein is used as a binding agent in RED wine, but not white wine. This is called fining the wine. And kosher wines may use albumen from egg whites, for the fining process but never casein. Nor do Vegan wines.
Here is an interesting article about the wine clarification process done by many but not all wineries. It comes from WiseGEEK.
What does wine have to do with animal tissues and bladders? A lot. As we know, wine is made mostly of grapes, yeast, and sulfites. Different environmental factors such as plants and soil, as well as the weather, can affect the outcome of the wine. That's what makes each winery unique. However, there is one common attribute in the wine industry - the finished product is always cloudy. Because many people object to cloudy wine, along with the sediment that is left floating in it, wineries send their wines through a clarification process called fining.
Fining eliminates the cloudy appearance of wine by removing the sediments. The fining agent, after being stirred into the barrel of wine, acts like a magnet by picking up the sediment in the wine and carrying it to the bottom of the wine barrel. After the wine is clarified, it is separated from the sediment during a process called racking, which leaves the residue behind. Fining can take on a whole new meaning if you are a vegetarian or a vegan. Many of the fining agents used are animal products. These animal products include albumen, casein, gelatin, and isinglass.
Albumen, which is produced from egg whites, is the most common fining agent. Egg whites are typically used in fining red wines. Wines fined with egg whites are acceptable to vegetarians but not vegans. Casein is a milk protein. Casein is also more commonly used in red wines. For someone with a severe milk allergy, it is wise to inquire if the wine they are drinking was fined with casein.
Gelatin is an animal protein from the skin and connective tissue of pigs and cows. Gelatin may be used in the fining process of either red or white wines. Isinglass (also called fish glue) is made from the bladder of the sturgeon fish. Like the other agents, this works like a magnet, attracting the impurities and carrying them to the bottom of the barrel or tank, producing a clean wine. Isinglass is found in many German white wines.
And from GlutenFreeFox.com,
How to avoid casein and other fining agents? First of all, don’t discriminate. Cloudiness of the wine is not a reflection of quality, but rather of lack of fining. Vegan friendly vinyards allow their wines to settle naturally instead of fining with animal products. Keep in mind, organic does not mean “vegan or vegetarian friendly.” Many “organic” vinyards do fine their wines with animal proteins. If a wine is labeled vegetarian, it should not contain casein, vegan will contain no animal products. So look for these labels.
Where to find vegetarian friendly and vegan wines? Look for the labels at your grocer, or try doing a search on Barnivore.com. And the good news is that casein free wine is not always more expensive. According to Barnivore: Charles Shaw (a.k.a. Two Buck Chuck) is not fined with casein or eggs, Bolla wines are vegan using no animal products and even Yellow Tail’s red wines are vegan. But going to the grocery without a proper list of vegan wines would simple make matters complicated, so I’ve used the resources on Barnivore to create a list of vegan friendly wines that’s perfect for taking to the wine store or a restaurant.
Too much information, as some say.
Just remember, if you’re allergic to casein, source out your next bottle of wine to be one that doesn’t have casein in it, and save yourself some grief.