The level of caffeine, of course, will depend on how much coffee you used in the recipe — just as your average cup of joe will be stronger with the more ground coffee, so will your wine.
Coffee wine, eh? I’ve heard of using strong black tea as a tannin additive and of using coffee in brewing recipes for a super-charged stout but I’ve never heard of making coffee wine. You and your father are quite adventurous — I hope that it turns out well. To answer your question about whether caffeine
Congrats on embarking on the ever-fascinating and (just as often) maddening adventure of using oak in home winemaking! You’ve discovered what many of your predecessors already have — that it is sometimes difficult to locate appropriate equipment, additives and supplies, especially in the smaller quantities and sizes that so many of us home winemakers require.
Discussions of wine aging range well into the past, from the biblical story of Luke and putting new wine into old skins, to the ancient Roman interest in Falernian wine, which could