What does “sulphidisation” mean?

If “sulphidisation” has the same meaning as the term “sulfurization”, to treat or subject to the action of sulfur, then I would have to definitely agree with Hoke’s and Howie’s assessment that “sulphidisation is the result of sloppy winemaking”.
But I truly think that a statement like “sulfur related problems are the result of sloppy winemaking” is very misleading. One should not think that “all” sulfur related problems are the result of “sloppy winemaking”.
There is literally hundreds of known sulfur containing compounds found in wines. Some of these compounds may contribute a positive characteristic others a negative characteristic. But if one thinks about it, any one of these sulfur containing compounds could be a source of sulfur and possible result in a negative characteristic or fault. In reality, I guess there is no way to produce a wine that is totally sulfur compound free, the only thing one can possible hope for is that the concentration of these compounds be kept at “acceptable levels” or at levels that can be held in “check” until the consumer can drink it. But then again, maybe in the future instead of using a living organism to conduct alcoholic fermentation, maybe winemakers will only use the “appropriate” enzymes to produce the so-called “ideal” wine.

Salute

Victor -

I'm coming in late here, but I agree that one would not want to eliminate all sulfur-containing molecules from a wine. It's hard for me to believe that some of those molecules don't contribute to the complexity and interesting flavor that we want in a wine. That said, most humans are quite sensitive to sulfur odors, so one does want to keep them within certain levels.

I also agree with you that there are probably other potential reasons for overly-sulphurous wines than sloppy winemaking. Late dusting of vines with sulfur to prevent mildew is one that comes to mind (although I'm not positive on this). Still, the winemaking process is where one would have the most control over how much sulfury smell ends up in the final product. My friends and I have struggled quite a bit with H2S in a couple of our wines. In at least one or two cases, I am pretty positive it's because we didn't get enough in the way of nutrition to the yeast. I don't know that this qualifies as sloppy winemaking so much as amateurish winemaking, but either way, we had to resort to copper treatment to get rid of the smell. It was a lot of work and a stinky learning experience, but then that's a big part of the fun of being a home winemaker. Getting away from the vagaries of yeast-driven fermentation would suck the joy right out of it!

Mike

The presence of too much sulfur as a noticeable flaw can be divided into two categories, SO2 and H2S and the two are totally different. Too much SO2, the burnt match aroma, is caused by the addition of too much SO2 during the winemaking process. Too little runs the risk of allowing the wine to spoil. Eventually, if too much has been added, the SO2 levels will decline over time and the wine will improve. Way too much can also have a bleaching effect on the wine and compromise its' overall quality. H2S (hydrogen sulfide) is a totally different problem and is quite common when many of the newer yeast strains are used without the addition of sufficient yeast nutrient, as Mike pointed out and happened in my '04 Cab Franc. This is also referred to as reduction, which is the opposite of oxidation. If left untreated the H2S can combine with other compounds in the wine and make mercaptans, which are very aromatic, stinky compounds the natural gas and propane industry add to their otherwise odorless products so that leaks can be detected. Once mercaptans form they are very difficult to remove. Of the two, I feel the latter is the bigger problem. However, both can be avoided by proper winemaking and monitoring. So, if these happens, is it sloppy? Well, if I detected these in a commercial wine, I wouldn't buy it. If I detected them in a wine while judging a home winemaking competition, I would deduct points. Other sulfur compounds do occur in wines, but to my knowledge they present no detrimental complications.

Thanks Mike and Howie for responding. Still not quite sure what the meaning of “sulphidisation” is, but I assume it means the same as sulfurization, to treat or subject to the action of sulfur.
Mike as far as late spraying of the vines with sulfur to prevent mildew, while it is not the responsibility of the amateur home (and professional) winemaker who out source his/her fruit, but he/she should understand or have some knowledge that this could lead to sulfur-related problems. Therefore I would include this (using elementary sulfur on the vines); poor cap and O2 management, poor temperature control during fermentation, poor lees management (racking regime), SO2 addition and (sulfur treatment of barrels) in the category of “sulphidisation”.
Howie as far as a wine getting “infected” by H2S sulfur related problem this could occur at various stages of a wines evolution. I agree that if the H2S problem occurs early during primary alcoholic fermentation or soon after, most likely the yeast strain used to conduct alcoholic fermentation produces a high concentration of H2S and the must or juice is probably low in yeast nutrients. But simply aggressively aerating or splash racking the wine at this early stage might stop the wine from getting infected with a H2S (hopefully the bulk of the H2S blows off), but the formation of H2S continues. A H2S problem could also show up near the early stages of MLF or at the end of MLF. Besides from what Mark Lipton posted in a previous post that mercaptans are formed by H2S reacting with alcohol and this reaction is not controlled by the presence or absence of O2 but by pH. Therefore exactly when mercaptans form could be when H2S and alcohol is present. Therefore a wine containing H2S could very likely contain some amount of mercaptans. Very likely however the mercaptans problem would most likely not be detected as a problem (not yet anyway). The concentration of H2S at this early stage (early or at the end of alcoholic fermentation) would very likely be greater than the concentration of mercaptans.

Salute