Wine for Consecration The bottom line is that store-bought wine that is clearly fruit of the grape vine is valid matter for the Eucharist. I have used it myself, for example, when on vacation and wanting to celebrate Mass, but I usually avoid cheap wines (e.g., “box” wines) and wines that look risky (e.g., blends). If possible, I buy a grape wine labeled as “organic” as it is more likely to be pure. The store-bought wine could, however, be illicit if there are any additives. Such additives may not be listed on the label and can simply be chemicals added before or during the fermentation process or preservatives, which usually are not problematic in very small quantities and are not merely added to finished products. However, additives may be things like cane sugar added in order to increase the alcohol content for grapes that are too low in sugar to make wine with the usual alcohol content. There is a risk that at a certain point, such additives if too great in quantity could become invalidating. To avoid such risks, it is generally preferable for parishes and chapels where Mass is celebrated regularly to purchase wine from approved sellers of wine for use at Mass. Interesting that in missionary countries where priests have had to make their own wine, especially in the past centuries, where local grapes were inferior for making wine or were not easily available, the Vatican encouraged the addition of raisins (which are more easily transported) to increase the sugar content of local grapes to make suitable wine with no risks of invalidity. ______________________________________________________________________________ In reference your question about the use of commercial wine at Mass, here is some basic information about Sacramental wine that you can use. In principle, any wine may be consecrated provided it is pure, unspoiled wine made from grapes. The Code of Canon Law states, "The wine must be natural from the fruit of the vine and not spoiled" (CIC 924). The General Instruction of the Roman Missal adds: “The wine for the Eucharistic celebration must be from the fruit of the grapevine (cf. Luke 22:18), natural, and unadulterated—that is, without admixture of extraneous substances. Diligent care should be taken to ensure that the bread and wine intended for the Eucharist are kept in a perfect state of conservation: that is, that the wine does not turn to vinegar nor the bread spoil or become too hard to be broken easily.” (GIRM 322–323) Regarding commercially available wine, the Holy See has been insistent that the sacramental or Mass wine come from sources beyond suspicion, since there are many ways in which wine can be vitiated or adulterated, many methods that are actually used to preserve, age, ameliorate wines. Wine should be purchased regularly only from reputable vendors of Mass wine or only when otherwise guaranteed to be pure and unadulterated. (The Sacraments and Their Celebration, Nicholas Halligan, 66–67) .