Methanol is one of the many alcohols produced during the fermentation process and in larger doses, it can sicken, or in rare cases, kill the person consuming it. All wine has a small amount of methanol in it, and commercial wineries are required by federal law to test their products before they're sent to stores. Many smaller personal wineries or wine hobbyists aren't as diligent in their testing, so if you're not sure about the amount of methanol in the wine you're about to drink, you can test the level yourself.
Things You'll Need
Red litmus paper
Two small samples of the wine
Two glass jars or glasses
Testing for Consumers
Place one sample of the wine in question (at least 1 oz.) in a glass container. Place a piece of red litmus paper in the sample and wait 2 to 3 minutes.
If the litmus paper turns blue, there is a potentially dangerous level of methanol in the wine and it should be discarded.
If you are forced to discard the wine, you should also contact the person who sold you the wine and/or the person who made it. It's likely that a number of bottles of wine came from the same batch and they are also contaminated with excess methanol.
Testing for Winemakers
Place one sample of the wine in question (at least 1 oz.) in a glass container. Add 5 grams of potassium dichromate and mix thoroughly. Let this sample sit undisturbed for at least 15 minutes.
Check the sample of wine after 15 minutes. Lift the container containing the alcohol sample and the potassium dichromate to your nose and sniff carefully. If you detect an acidic or slightly burned smell, discard the wine immediately.
If you do discover your wine is contaminated with excess methanol, you should carefully review your entire winemaking process. It's likely that a flaw in your technique is causing this problem.
There are two easy ways to cut down on the chances of creating a wine or alcohol with a dangerous level of methanol. Discard the first liter of liquid created in the fermentation process, because it tends to include the highest concentration of methanol. Methanol also has a lower boiling point than the other ingredients, so a careful tracking of the temperature during the fermentation process will greatly lessen the chances of a problem later on.