Wine and Candida Yeast
Yeast infections are an unfortunate fact of life for many women out there. I used to get regular yeast infections when I ate a sugary diet, and it took me a while to get that all sorted out. Just a note, when I went to a low-sugar diet all my yeast infection issues pretty much vanished and have for many years.
Many women who are dealing with yeast infections want to know what part wine might play in feeding the system.
First, wine is made with yeast. Not with Candida yeast, obviously, but with winemaking yeast :) Grapes have natural sugars in them, so what the wine makers do is then dump a bunch of yeast into the squished-up grapes and the yeast merrily muches on those sugars. The byproduct of that yeast activity is alcohol and carbon dioxide. The carbon dioxide naturally just floats away. The alcohol stays. So this is how wine becomes alcoholic - the yeast creates the alcohol while it digests the sugars.
Usually a winemaker will use a yeast which dies at a certain alcohol level. So say the winemaker is aiming to make a Zinfandel wine which is 14% alcohol. They will simply use a yeast type which dies in a solution of 14% alcohol. The yeast is quite happy and fine as the alcohol level is 1%, and 2% and so on but once it reaches 14% they die (of alcohol poisoning in essence). So now the wine is done, the alcohol is at 14% and the yeast is dead. It does sound sort of mercenary :)
Wine is NEVER cooked. That would cause huge damage to a wine. If anything, wine is kept cooler than room temperature during all of this process, so that the yeast do their processing smoothly and so the grapes and wine retain all of their flavors. So the wine is never "roasted" to kill off the yeast. That would make for awful tasting wine. The yeast are slain by the alcohol levels.
No wine you get will ever have active yeast in it. The dead yeast cells settle on the bottom of the fermentation tank and are not put into the bottles.
Now, just to be picky, a FAULTY wine might sometimes have yeast present. This would be a serious breakdown of a winemaking process and might happen with a small farm winery for example. Wineries normally test a wine to ensure all the yeast are dead before they go to bottling. The yeast are slain by the alcohol poisoning as mentioned above, or a membrane / sterile filter is used to filter out any remaining yeast cells. If that process fails for some reason - the membrane has a rip in it or something - the testing will alert them to that and they'll refilter. However, very small wineries can't test in-house. They send their samples out to a lab. If they are then impatient and start bottling and shipping without waiting for those test results, consumers might end up getting bottles in their hand with active yeast.
Really, this isn't a big deal. People eat yeast all the time :) What it does mean is that the yeast, being active and alive, might keep processing sugar and creating carbon dioxide. It might actually push the cork out of the bottle either slightly or fully because of the carbon dioxide being created :) So this fault might cause the wine's alcohol levels to rise slightly, and cause strange cork problems. It won't actually damage the wine (unless you consider having a wine with slightly more alcohol to be damaging ;) ). So in any case, if you find a small-winery wine with the cork pushed out, this might be what happened to it.
In terms of sugar - something else a person with a yeast infection would worry about - there is pretty much always some level of residual sugar left in a bottle of wine. Again, the process starts with actual grapes - with grape sugar in them naturally. That grape sugar is why grapes are sweet. When the winemakers mash up the grapes, you now have grape juice. You add in the yeast which converts MOST of that sugar into alcohol. However, the yeast rarely converts every single last little molecule of grape sugar into alcohol. There is pretty much always some small amount left. Not enough that you really think of wine being a "sugar drink" - but more than zero.
If you're going to take that point of view, though, and worry about those few drops of sugar, pretty much every single fruit, vegetable and grain product has at least some small level of sugar type substance in it. People fighting yeast infections generally cut out high-sugar things like sodas, but it is a losing war to try to cut out every iota of sugar from your diet. The many benefits of wine really outweigh trying to worry about the molecule or two of sugar which might be lurking somewhere in there.
Note: A great deal of research and work went into my wine / health pages. If you use this information, please credit me properly. Thanks!
Wine and Health