Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: pensador on 02/10/2020 14:55:01
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Potassium metabisulphate is added to wine as a preservative and is referred to as sulphites
Can Sulphites be removed from wine by any other mechanism other than adding hydrogen peroxide.
Evaporation in cooking and aeration are suggested. Ethanol Alcohol starts to evaporate at about 78C. At what temperature do sulphites evaporate if at all????.
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The whole point of adding metabisulfites to wine is to preserve the flavor and inhibit secondary fermentation. Boiling the wine will leave you with a residue of sticky grape sugars and a tiny trace of potassium sulfite, and some rather raw brandy with a hint of sulfur dioxide in the distillate.
Given the choice, I'd rather drink my Mouton Rothschild as it came in the bottle, along with whatever additives the good burghers of Pauillac have deemed fit to use for the last 170 years.
My own garden produces an adequate grape juice, and I sometimes add a hint of Na2S2O5 to stop it turning into Chateau Calverd, or after adequate fermentation to prevent the Grand Cru turning into expensive vinegar - Sarson's Malt is a better match with chips.
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sulfites (sulphites) are unlikely to volatilize--you can get rid of them by oxidation, but why do you want to? They are protecting the wine by essentially serving as sacrificial reducing agents (oxygen in the air will react with sulfite before it oxidizes components of the wine)
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The whole point of adding metabisulfites to wine is to preserve the flavor and inhibit secondary fermentation. Boiling the wine will leave you with a residue of sticky grape sugars and a tiny trace of potassium sulfite, and some rather raw brandy with a hint of sulfur dioxide in the distillate.
Given the choice, I'd rather drink my Mouton Rothschild as it came in the bottle, along with whatever additives the good burghers of Pauillac have deemed fit to use for the last 170 years.
My own garden produces an adequate grape juice, and I sometimes add a hint of Na2S2O5 to stop it turning into Chateau Calverd, or after adequate fermentation to prevent the Grand Cru turning into expensive vinegar - Sarson's Malt is a better match with chips.
I am new to making wine. My wine so far this year tastes a lot better than a lot of shop bought wine. The only big mistake was pressing my first reds too soon, giving me a rose, instead of a red. Still tastes good though :)
All wines contain sulphites naturally. There is a recommended max level for sulphites in wine. Apparently due to some possible allergic reactions.
I do not understand how k-meta can be removed by aeration or splash racking as is claimed by some.
Vigorously aerating a dodgy wine often improves it, to the point that it is drinkable. Even a good wine can be improved by aerating it.
K-meta is used as a preservative, but people sometimes accidentally over dose :-[ not me as yet, although I did have a slow ferment on my white wine, which I attribute to k-meta. I understand even using k-meta secondary fermentation can start again. If you dont have test equipment for k-meta 50ppm/litre potassium meta-bisulphate is the usual dose before adding yeast, if you are not doing a wild ferment that is. 50ppm/litre is then added after the first racking to like you say kill any bacteria, and hopefully any remaining yeast, thus preserving the flavour.
(Has this site got an american spell checker ? flavor or flavour )
I have a friend who reckons sulphite gives him a head ache, which I think is wrong as it is used as a preservative on all kinds of foods.
I have read that aerating a wine that has been over sulphited removes the sulphite. I have also read that this is wrong! Is either statement correct ????????????????.
PS How do you measure the sulphite level, if at all, in your Chateau Calverd ?
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sulfites (sulphites) are unlikely to volatilize--you can get rid of them by oxidation, but why do you want to? They are protecting the wine by essentially serving as sacrificial reducing agents (oxygen in the air will react with sulfite before it oxidizes components of the wine)
My friend reckons he gets headaches from them so, if he can aerate a wine and accelerate oxidation thus removing sulphates prior to drinking the wine, his theory on his headaches might be removed?
K2O5S2 oxidizes to form what?
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K2O5S2 oxidizes to form what?
KHSO4
I can't see hydrogen peroxide working very well. It's got to find a few hundred ppm of sulfite among a few percent of alcohol, not to mention all the other stuff it could react with.
I do not understand how k-meta can be removed by aeration or splash racking as is claimed by some.
The sulphite is in equilibrium with SO2.
And aeration will remove that as a gas.
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sulfites (sulphites) are unlikely to volatilize--you can get rid of them by oxidation, but why do you want to?
Because sulphites are in equilibrium with SO2 they are very likely to evaporate.
You might want to get rid of them because the smell of spent matches doesn't improve the wine (or cider or whatever).
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k-meta
k-meta = Potassium Metabisulphate = K2O5S2
...so you don't need to look it up, too!
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How do you measure the sulphite level, if at all, in your Chateau Calverd ?
I assume that most of it is whatever I put in, generally one Campden tablet per gallon. Measure???? This is an artisan product!
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All wines contain sulphites naturally. There is a recommended max level for sulphites in wine. Apparently due to some possible allergic reactions.
If your friend has asthma there is a 5-10% chance he has a sulphite sensitivity, however, as you say there is a lot more sulphites in other foods and he ought to recognise his sensitivity through those.
For wine the maximum legal limit in the United States is 350 mg/l. Wine ranges from about 5 mg/L (5 parts per million) to about 200 mg/L, a good dry red wine typically has about 50 mg/l.
There are wines which claim to be sulphite free, mainly in the organic, biodynamic and vegan markets. The problem is that under EU & US law a wine below 10mg/l is considered sulphite free, so can be legally free, but not totally free.
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The problem is that under EU & US law a wine below 10mg/l is considered sulphite free, so can be legally free, but not totally free.
The problem is that yeast produces traces of sulphites so a wine won't be sulphite free.
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K2O5S2 oxidizes to form what?
KHSO4
I can't see hydrogen peroxide working very well. It's got to find a few hundred ppm of sulfite among a few percent of alcohol, not to mention all the other stuff it could react with.
I do not understand how k-meta can be removed by aeration or splash racking as is claimed by some.
The sulphite is in equilibrium with SO2.
And aeration will remove that as a gas.
Thats what I wanted to know Thanks.
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All wines contain sulphites naturally. There is a recommended max level for sulphites in wine. Apparently due to some possible allergic reactions.
If your friend has asthma there is a 5-10% chance he has a sulphite sensitivity, however, as you say there is a lot more sulphites in other foods and he ought to recognise his sensitivity through those.
For wine the maximum legal limit in the United States is 350 mg/l. Wine ranges from about 5 mg/L (5 parts per million) to about 200 mg/L, a good dry red wine typically has about 50 mg/l.
There are wines which claim to be sulphite free, mainly in the organic, biodynamic and vegan markets. The problem is that under EU & US law a wine below 10mg/l is considered sulphite free, so can be legally free, but not totally free.
No he doesnt have asthma, hes a ENT medical doctor retired, knows something about everything. He argues aerating the wine does not remove sulphites which he insists give him a headache.
I have dosed my wine twice so far, once before pressing, and once after the first racking. I am dosing at the recommended dose of 50ppm. 50mg/litre > 100litres of wine gets 5g, or 1 teaspoon.
Even after 10 doses at this rate, I will not have introduced that much k-meta into my wine, and since it evaporates, my friend is going to have to find another excuse for his wine headaches.
How do you measure the sulphite level, if at all, in your Chateau Calverd ?
I assume that most of it is whatever I put in, generally one Campden tablet per gallon. Measure???? This is an artisan product!
I couldnt find any Campden tablets so I used k-meta powder, for my wine this year. Next year when I have learned what not to do, through my mistakes, I might call my wines artisan wine. This year I am being lucky so far, the mistakes are not so bad. ie I have a deep rose instead of a dark red wine.
This wine making business to me seems to be more good luck than judgement/measurement so far.
Measure ????? Dosing in ppm is easier to work out in litres rather than gallons. With US gallons being the standard measure on most wine making forums, do you need to add a bit more Campden tablet for the UK gallon? :)
Using either Campden tablets or k-meta at the prescribed levels makes it very difficult to achieve anything near the legal limits for wine.
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find another excuse for his wine headaches.
Has he considered alcohol?
Has he considered the placebo effect's darker cousin?
https://en.wikipedia.org/wiki/Nocebo
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do you need to add a bit more Campden tablet for the UK gallon?
No
Campden is in England and the tablets are the right size for a proper gallon
The Americans have been getting it wrong.
.I am dosing at the recommended dose of 50ppm.
50parts of what per million?
50 parts of SO2?
or SO3--
or Na2S2O5
or K2S2O5?
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do you need to add a bit more Campden tablet for the UK gallon?
No
Campden is in England and the tablets are the right size for a proper gallon
The Americans have been getting it wrong.
.I am dosing at the recommended dose of 50ppm.
50parts of what per million?
50 parts of SO2?
or SO3--
or Na2S2O5
or K2S2O5?
Those Americans keep getting it wrong, but they do make more wine than the Brits. I didnt know that Chipping Campden, is where they were developed https://en.wikipedia.org/wiki/Campden_tablet#:~:text=The%20name%20Campden%20tablet%20comes,.%2C%20who%20developed%20the%20tablet. Thanks for that little ditty.
Potassium Metabisulphate K2S2O5 is what I have been using.
I dont use Sodium-Metabisulphate because some claim it introduces the smell of burnt matches, also it is not available here :)
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Thanks for that little ditty.
A ditty is a song.
I dont use Sodium-Metabisulphate because some claim it introduces the smell of burnt matches,
The smell of burned sulphur is the same whether it is from potassium bisulphite or sodium bisulphite.
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My favorite cartoon was of a college gardener revealing the secret of King's lawn to a tourist: "You mows it, and you rolls it, and once in every 200 years...."
Thus with wine. You can measure ppm SO2 in a laboratory, and get a million gallons of potable 12% ethanol every time, or you can muck about in a cellar for 200 years and, once in a while, produce a work of art.
On the headache side, I was introduced to South African organic wine by a friendly native who insisted I wouldn't get a hangover as they didn't use arsenical antifungals. I'm not sure if anyone actually does, but we got thoroughly plastered on his best Shiraz and I woke with a perfectly clear head.
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produce a work of art.
As judged by what?
The same people that think an unmade bed is art?
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find another excuse for his wine headaches.
Has he considered alcohol?
Has he considered the placebo effect's darker cousin?
https://en.wikipedia.org/wiki/Nocebo
I did wonder if on occasion his wine might have some methanol in it. Red wine made on grapes skins and stalks maybe rather than just the fruit might maybe. The woody stalks might develop Methanol rather than Ethanol, but happily since I dont get hangovers I am using k-meta.
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Thanks for that little ditty.
A ditty is a song.
I dont use Sodium-Metabisulphate because some claim it introduces the smell of burnt matches,
The smell of burned sulphur is the same whether it is from potassium bisulphite or sodium bisulphite.
I dont think either additive are going to reach the levels for combustion in a cask of wine required to make them decompose. K2S2O5 → K2SO3 + SO2 and happily my wine doesnt smell of sulphur.
As a complete beginner to the making of fine wines, I am taking advice, and I read sodium metabisulphate is claimed by some to leave a hint of burnt matches. Since I cant buy it where I live, it is not an issue for me. From the little I have found out about making wine it seems there is no right and wrong way. Some dont use any additives and do alright. I am using k-meta so I do not windup with vinegar, and I used cultured yeasts and nutrients to control the flavour and any off odours, such as methane.
What in some wines apart from the alcohol cause some people to get headaches? How about low levels of methane which can be produced if the wrong nutrients are supplied to a yeast during fermentation. Maybe low levels of methanol which I understand can be produced during fermentation from woody stalks, or even seeds.
Does aerating the wine remove off gases, locked in the wine, and if so could aerating a wine remove the cause of hangovers?
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produce a work of art.
As judged by what?
The same people that think an unmade bed is art?
My daughter studied to be a Master of Wine and has a pub licence. Eldest son is a chef. I tend to agree with them on matters of taste, and in this family at least a good Pauillac ranks alongside an early Picasso, but more affordable.
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I couldn't find any Campden tablets so I used k-meta powder, for my wine this year. Next year when I have learned what not to do, through my mistakes, I might call my wines artisan wine. This year I am being lucky so far, the mistakes are not so bad. ie I have a deep rose instead of a dark red wine.
This wine making business to me seems to be more good luck than judgement/measurement so far.
I used campden tablets for convenience when I first started, but moved to metabisulphite and measured out a dose.
I'm just about to rack some mead, but I'll decide on treating based on how far it has used up the sugars.
Although there is a degree of luck (or statistical variability!) I try to keep records to aid consistency and avoid serious errors.
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I'm just about to rack some mead
mead gives a man a halo!
Distillation is legal where I am!
I just had an excellent success, in my opinion, distilling the lees from 30 litres of red wine I racked, producing a couple of bottles of grade A agua dente. It really has an excellent flavour. Possibly the best I have tasted so far! Next year I will be distilling the lees and not trying to extract the last drops of wine.
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hi
you are talking about Sulphites be removed from wine other than by adding hydrogen peroxide.
i think this is an experiment .you have try in the lab or plz do google about it hope you find your answer.