From a priest:
Are there any rules or traditions about the type of wine used the chalice? I know it must be fermented grape juice – but must or can it be it be red, white, sherry, port?
It is of divine institution that the only valid substances for transubstantiation are, for the Body of the Lord bread made from wheat and, for the Precious Blood, wine made from grapes or raisins (dessicated grapes). But the grapes also have to be ripe, which rules out “wine” such as verjus (I actually have some, for ancient Roman and Medieval recipes). It can be red, white, dry, sweet, whatever. Some prefer red because it resembles blood. Some prefer white because it is easier to clean the linens.
Sometimes questions come up about the use of wine which has very low alcohol content, called mustum, a wine which had the fermentation process halted by means of rapid freezing. That is a valid substance because it is from grapes and the natural fermentation process began, making it wine. It has an artificially low alcohol content, but mustum is consider valid wine.
However, there is the other end of spectrum to consider: wine which has an artificially high alcohol content. Sometimes alcohol distilled from wine is added to wine in order to preserve it against spoiling, changing to vinegar. In this case we have “fortified wine”. The usual types of “fortified wine” we encounter are port, sherry, madeira, marsala, and vermouth.
Long ago it was established that fortified wines are valid matter so long as the wine-spirit added was distilled from grapes, that the quantity of alcohol added, together natural content from the fermentation, does not exceed 18% and that the additional alcohol is added during the process of fermentation. You can read a good, brief article on altar wine in the Catholic Encyclopedia. Also, because we are at heart Unreconstructed Ossified Manualists, we want to check our old manuals. What could be better than checking Tanqueray’s Theologia Dogmatica?
Again, we learn that it has to be from ripe grapes, it can be of any color, not corrupted, not frozen at the time of consecration. Citing the Missale Romanum we are warned against wine that is turning bad. As a matter of fact, if the priest is doubtful about it, he sins gravely by consecrating it. “Si fuerit aliquantulum acre, ait Missale, conficiens graviter peccati.”
By the way, the coffee mugs are not at the moment filled with any of the beverages mentioned in this post.. until now… try some Mystic Monk Coffee! It’s swell!
I would rule out vermouth, because herbs and so forth are added. I would not go for sherry because, if I am not mistaken, the addition of the spirits takes place after fermentation. Marsala seems to be okay, so long as it is 18% or less. Vin Santo, from dessicated grapes, is fine. As the name implies, it is wine for the altar! Port is valid, 18% or under.
Perhaps some people knowledgeable in the ways of port (making, not drinking) and marsala (not just cooking) can chime in.
Furthermore, this is a good reason why there are ecclesiastically approved makers of altar wines. If you have a doubt, don’t screw around with anything that may not be valid.
To be fair, it is juxtaposed with a lecture by Peter Kreeft and an ad for confessions.
What sort of people work for 
From a priest:
Fr. John Zuhlsdorf on ASK FATHER: If a bishop and also priests confirm at the same time, who is the minister of confirmation?: “Bruised: You might be limiting your vision of the Church, which extends beyond where you live. There are places in…”
