Bottling is one of the most important steps in making kosher wine. Though Jewish dietary law does not limit the grapes in kosher wine-making (there are no non-kosher grapes), following strict rules for the bottling of that wine is of utmost importance.

As we mentioned earlier, while most of the ingredients that go into making wine are regulated by Jewish dietary law, kosher wine deals more with who handles the wine and the way it is produced. Also, wine that is sold as kosher for Passover must not come in contact with grain, bread, dough, or even yeast.

One of the most important aspects of Jewish dietary law as it relates to kosher wine-making is the belief that no idolater can have a hand in any step of the wine-making process, including bottling. In fact, a kosher wine can not be made or poured for idolatry either, and to this end a rabbi is generally expected to oversee the bottling of the kosher wine to ensure that it adheres to these rules.

One such method for ensuring wine was not nor will be used by idolaters is boiling wine, which results in a product known as mevushal. Boiling wine makes it unfit for use in idolatry, guaranteeing the wine will not be used for this purpose. Originally the kosher wine-making process of boiling wine was taken literally where the wine was boiled out. This drastically affected its taste and make-up. More recently, mevushal is only heated to a temperature of 194 degrees F (90C) where the wine is cooking but doesn’t reach a rolling boil. The result is a mevushal that more closely resembles normal wine, but is still affected. The cooking process destroys some of the good bacteria on the grapes and also affects the aging ability of the mevushal kosher wine.

Some disagreement exists over current wine-making and bottling processes as it relates to kosher wine-making. Some rabbis argue that most bottling of wine today is an entirely automated process and so is not “made” by Gentiles. Also the automated wine bottling process is not done specifically for any religious rites anymore, much less specifically for worshiping false idols. The argument then is that any modern wine is kosher given modern wine bottling techniques. Many conservative rabbis disagree with this stance, stating that there is no way to tell if every wine is made in this way and/or has not been poured for or touched by idolaters, so only hechsher-rated mevushal is truly kosher wine.