Screw top wines being ruined by sulphidisation?

[Robin Garr]

Um.



Not that I'm gloating, mind you....but I told you so.



I apologize in advance for being right....then getting klicked off of this BBS for saying do.




Not the I'm bitter, mind you.

Tim, I explained to you last time why you were being given a time out and why it had absolutely nothing to do with your opinions.

I accepted your plea to be accepted back in the forum on the agreement that you understood this and that it would never happen again.

Good bye, Tim.

Isn't this where you're supposed to put a new penny in the wine (or something else clean and made of copper) to absorb or combine with the Sulphur? I thought I might make a copper stir-stick out of 10 guage copper wire. This could be fun to take to a restaurant.

[Robin Garr]

Isn't this where you're supposed to put a new penny in the wine (or something else clean and made of copper) to absorb or combine with the Sulphur? I thought I might make a copper stir-stick out of 10 guage copper wire. This could be fun to take to a restaurant.

Bob, correctamundo. A lot of people assume that the "penny trick" is an urban legend, but I've seen wine makers do it and I've done it myself. Even though modern pennies don't have much copper left in the cladding, there's apparently enough. I actually keep a very clean Euro cent around in the belief that it has a little more copper, or else better magick.

I wrote an article about this years ago, quoting the forum's Stuart Yaniger on the fairly simple chemical process in play: "The copper reacts with H2S to form copper sulfide, which is insoluble ... In the absence of shiny pennies (or for those squeamish about the contents of their pocket), silver works even better. Use a polished silver spoon for a minute or two and watch the tarnish form!"

Um.



Not that I'm gloating, mind you....but I told you so.



I apologize in advance for being right....then getting klicked off of this BBS for saying do.




Not the I'm bitter, mind you.

Tim, I explained to you last time why you were being given a time out and why it had absolutely nothing to do with your opinions.

I accepted your plea to be accepted back in the forum on the agreement that you understood this and that it would never happen again.

Good bye, Tim.

No problem.


I was just giving a little perspective.


It won't happen again. I beg your pardon for speaking my mind.



My bad.

But the copper penny only works if it is only H2S, right?

I don't find that it works with the problems I'm experiencing

and it doesn't work with any mercaptans (I was taught that in winemaking class! there are no quick fixed for mercaptans, just carbon filtering or other radical techniques, if I remember correctly)

The only thing that works, it seems, with the matchstick sulphur smell, is putting my hand over the glass and shaking the crap out of it, then letting it sit a bit (Tony Gismondi taught me that one), or, if I have time, "crash decanting" it and putting it in the fridge* for a while

*I have only noted this problem with whites - it seems more prevalent in fruity and especially off-dry whites, I gather because they tend to sulfite these more for stability? Or, maybe reds have more other things to hide the sulphur smells

Craig,
The copper penny treatment will reduce mercaptans, stirring the wine vigorously will reduce H2S.

Salute

okay i have fired off a note to my instructor!

i want to see what he says about these S issues, because clearly my memory is bad (i was not a student -- I ran the course, so I just sat in and listened). I was sure he told us that the penny does not work with mercaptans, unless he meant a certain class of mercaptans, because i gather from that article there are quite a few

this guy is one of Canada's best technical winemakers - so I trust whatever he says. in his years at Andres he doctored more wine than all of us together have drunk in our lives

[David M. Bueker]

The thing that is important to keep in mind is that winemakers can adjust their handling of the wine at bottling to reduce these reduction issues. Some have learned how to play with screwcaps, others have not.

Of course some storied domaines still don't know how to bottle properly with corks (witness DRC overfills as a prime example).

Ok i had a long conversation with Bruce Ewert (L'Acadie Vineyards, formerly of Summerhill Pyramid, Hawthorne Mountain, Sumac Ridge, and one of our MEGA factory winemakers before that) about this, and i learned some stuff but I still think there's a hole in my knowledge!

yes, i was confused about mercaptans - they can be removed by aeration or copper - it is disulphides (burnt rubber, garlic, etc.) that need treatment to send the reaction the other way back to mercaptans, so they can be dealt with

but Bruce agreed with me that what i am probably smelling is SO2 from oversulphited wines, not H2S that should not be there in any noticeable quantity if winemaking is done properly.

he advised me to watch for new organic policies (Canada) that will result in lower sulphite wines, and ONLY natural cork wines, so that there should be no sulphury nose in his wines, H2S or otherwsie! Hey, you can't blame him for trying to make a sale

Actually, what Bruce is doing is one of the most exciting things in Nova Scotia (and in fact Canada) wine. He's making traditional method sparklers, and wines from dried grapes, all organic, and not just the vineyard. Organic, period. He is one of two new wineries openign in NS this year who specialize in TM sparklers. The climate is perfect.

I tasted his sparkler a few weeks ago (not to be released until May) and it was fantastic. Made from L'Acadie, a grape grown almost exclusively in Atlantic Canada. I think it had 18 months or maybe 24 of bottle conditioning. Similar to premium Sekt.

Bruce won many medals (best in Canada, several tuimes) for his TM sparklers, including Riesling based, in BC.

I can't wait for these wines to come out!

Even though modern pennies don't have much copper left in the cladding, there's apparently enough.

Pennies made prior to 1982 have much more copper. Check those change jars!

Since H2S is highly volatile, early detection of the rotten egg odor can be “cured” with subsequent racking with deliberate splashing. Failure to treat H2S in its early stages will only add to your problems later, as H2S, when it interacts with alcohol, produces mono-mercaptans (sulfides) which have a range of odors - garlic, cabbage, onion, rubber, skunk, burnt-matches etc - and are more difficult to remove because, unlike H2S, they are much less volatile having become bound through interaction with alcohol. Even at this stage it is possible to treat the wine and remove the offensive odor, but it is more difficult to do so. One can successfully remove mercaptans in their early stages by a combination of aeration and Robin’s copper penny trick. It is absolutely essential that the wine be exposed to as much of the copper surface as possible and that the copper be free from contamination resulting from handling.
If one has not dealt with either the H2S or the mercaptans, then you are in trouble big time because now the mercaptans, if the wine has undergone any oxidation (which occurs during barrel ageing), have formed poly-mercaptans (disulfides) To remove disulfides first you have to break them down to sulfides (ascorbic acid solution) then treat with copper.


Salute

http://www.winebusiness.com/ReferenceLi ... taId=39044

this is a good article, with graphs showing that screwcap wines have higher SO2 in them after an aging period, even when starting with less. cork wins here.

the head space differences are interesting too

there are comments from randall (you know who) there which are interesting, since his Pacific Rim Riesling went totally reductive on the shelves here, and was delisted and put on sale to get rid of the sulphury garbage. It started out as a nice value riesling BTW, and I recommended it in a column, so when I went back to buy some on sale and opened the bottle, I was like "Gak! I recommended this?" The perils of being "the people's nose & tongue"

and a further note on SO2. Excess SO2, which smells of brimstone (which many of you will smell in excess...SOME day , apparently cannot be gotten rid of so easily by stirring/shaking/decanting/pennyizing. It needs much more time to dissipate. So it is better if the defect is H2S, I guess, than excessive sulfiting. Most NZ/Aussie winemakers, it appears, have learned to reduce the initial SO2 in their capped wines, so that it will be below threshold when people go to drink the stuff... So the Fat Cat I had must have been a blip.

Since H2S is highly volatile, early detection of the rotten egg odor can be “cured” with subsequent racking with deliberate splashing. Failure to treat H2S in its early stages will only add to your problems later, as H2S, when it interacts with alcohol, produces mono-mercaptans (sulfides) which have a range of odors - garlic, cabbage, onion, rubber, skunk, burnt-matches etc - and are more difficult to remove because, unlike H2S, they are much less volatile having become bound through interaction with alcohol. Even at this stage it is possible to treat the wine and remove the offensive odor, but it is more difficult to do so. One can successfully remove mercaptans in their early stages by a combination of aeration and Robin’s copper penny trick. It is absolutely essential that the wine be exposed to as much of the copper surface as possible and that the copper be free from contamination resulting from handling.
If one has not dealt with either the H2S or the mercaptans, then you are in trouble big time because now the mercaptans, if the wine has undergone any oxidation (which occurs during barrel ageing), have formed poly-mercaptans (disulfides) To remove disulfides first you have to break them down to sulfides (ascorbic acid solution) then treat with copper.


Salute

Victor,

I once had to do this with 500 gallons of Gewurztraminer, which suffered from poor nutrition during fermentation. I got it late and had to treat with ascorbic and copper sulfate--it worked, but it's a scary prospect, and SO2 additions thereafter must be carefully controlled.

The funny part of the story is that after spending a day in the winery dealing with a garlic/onion aroma, I go home to find my wife preparing an onion tart dinner, which I love, but found difficult to eat that evening

I realize this is a resurrected thread, but I keep coming back to it thinking that "Bucko" has returned.

Thanks for the story Thomas.


SO2, (which has a stinging and suffocating odor) can sometimes be noticed just after a bottle of wine is opened. This however rapidly disappears from the open bottle because of the high volatility of SO2. This sulfur component is therefore not usually important for its own odor. However it has a high affinity to bind with acetaldehyde.

Salute

Thanks for the story Thomas.


SO2, (which has a stinging and suffocating odor) can sometimes be noticed just after a bottle of wine is opened. This however rapidly disappears from the open bottle because of the high volatility of SO2. This sulfur component is therefore not usually important for its own odor. However it has a high affinity to bind with acetaldehyde.

Salute

Would that be the case with an oversulphited wine, too? Or could it continue to evolve SO2 (coming out of solution) until...until...I don't know what! Until there is equilibrium?

The actual concentration of SO2 will be determined by the pH.
Being an amateur winemaker I prepare stock solutions of potassium- metabetabisulfite, within a week I have to re-calibrate them for [SO2]; six months these solutions become more or less useless.

Salute

I think I have to give up on this -- next time I encounter a screwcap wine with the defect, I'll post my experience (could be soon as I have several samples to review that are under cap)

I think I have to give up on this -- next time I encounter a screwcap wine with the defect, I'll post my experience (could be soon as I have several samples to review that are under cap)

Craig,

The simplest way to think of the situation is this: reduction, the process that leads to mercaptan, etc., has an easier time in bottled wine when it is oxygen starved; additions of SO2 are in wine to slow down oxidation; unlike corks, screwcaps prevent oxygen transfer into the wine; put a wine in the bottle with high SO2, screwcap it, and you have increased the odds of reduction.

A lot of wine industry people believe that winemakers could control reduction under screwcap by being extra careful about their SO2 additions before bottling. As Victor says, pH (and tannin, too) are important guidelines for establishing SO2 levels. Generally, a clean wine with a pH at 3.3 needs the minimum SO2 additions. Fruit bombs often come with high pH; what saves them from needing higher SO2 additions is their intense tannins.

The actual concentration of SO2 will be determined by the pH.

That's an important factor, but not the only one. When winemakers talk about "free" and "bound" sulfite, they are talking about the chemical reaction with phenols and aldehydes in solution. The position of the equilibrium between bound and free depends on pH, so the overall amount of bisulfite that you need to get a certain level of free SO2 depends on both pH and must weight.

Being an amateur winemaker I prepare stock solutions of potassium- metabetabisulfite, within a week I have to re-calibrate them for [SO2]; six months these solutions become more or less useless.

That's a different story, though. Your metabisuilfite is slowly oxidizing in solution to potassium sulfate (which isn't that soluble and drops out of solution eventually).

Mark Lipton

Even though modern pennies don't have much copper left in the cladding, there's apparently enough.

Pennies made prior to 1982 have much more copper. Check those change jars!

Apparently the copper content of modern pennies is very low, but it's all on the outside, so I don't think it would make any difference.

All I’m trying to say Mark is that SO2 is a very volatile compound and under certain conditions it can dissipate fairly quickly. Yes in a medium such as wine and under enclosures which have a tight seal it will dissipate "slowly". I believe even some of the “bound” [SO2] will become “free” [SO2]. Just try and leave an opened bottle of wine on the counter for an “extended” period of time and see how long it takes before it starts to “turn”.

Salute

I'm sure SO2 is at least partly responsible for what I'm getting, because I get that irritation in the nose, and I definitely taste it.

It would be interesting to see how many of the wines tested at the British testing that were under cork were 'off' in any way . . . It would also be interesting to see if any of the wines bottled with screw caps were also bottled with corks and if any of the wines under cork had sulfide issues . . .

So much is made of sulfur issues with screw capped wines, but it seems that so much of the info is anecdotal and not 'actual'. I have opened wines under screw cap that appeared to be a little 'funky' but after normal aeration 'came to life'. I have not, nor have I found anyone else that has systematic problems with screw cap wines . . . My eyes and ears are open to the market and would love to hear from anyone that has experienced these issues . . .

I will be bottling all of my own wines - whites, rose, and reds - under screw caps . . . I do not want to deal with 'off' bottles due to cork issues . . .

Just my $.02 . . . Cheers!