Mike Parisi
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If you have a wine thief, try using that to stir. It won't displace much of the wine at all.
carboy aging
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If you have a wine thief, try using that to stir. It won't displace much of the wine at all.
I wonder about this. Do you uncork your bottles every 3 months and add Kmeta? If the carboy is sealed with very little headspace, why would you need to open it and add Kmeta every 3 months? On a percentage basis, the air in a carboy is less than in a bottle of wine. If you seal it with a cork or a cap, and it doesn't leak, I don't see why you would need to open it and add Kmeta.
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The answer to that question is in one of your assumptions, it does leak, without a doubt. The interference fit in the top of the carboy isn't that good.
@Raptor99, expanding what @cmason1957 said, the SO2 gets used up. It works by combining with contaminants, so over time the SO2 level is reduced. Given the relative leakiness of any winemaking container with respect to corks, contaminants are introduced to the wine.
@cmason1957 I understand your concern. @winemaker81 Would SO2 also get used up in bottles sealed with corks? From what I understand, wine aged in bottles with corks can breathe a little bit, which helps with aging. Wine aged in barrels also breathes. So I guess the key questions are:
* Can you seal your carboys so that they do not breathe more than an equivalent amount of wine in a bottle or a barrel?
* Is there a risk of harmful microbes getting into your carboy during bulk aging?
Several people on this forum have commented that they bulk age their wines. I would be interested to hear what they have to say about this issue.
* Can you seal your carboys so that they do not breathe more than an equivalent amount of wine in a bottle or a barrel?
* Is there a risk of harmful microbes getting into your carboy during bulk aging?
Several people on this forum have commented that they bulk age their wines. I would be interested to hear what they have to say about this issue.
@Raptor99, this is a complicated issue and I'm not going to tell you I'm an expert. Following is my understanding.
Wine contains contaminants from the crush, more is introduced by various actions. Light and heat affect wine. The SO2 binds chemically to contaminants and renders them harmless. ALL bulk aging containers have flaws, and racking has the potential to introduce contaminants.
Sounds absolutely horrible, right? No one is going to have wine survive the first week!
Nope. Between the ABV, the acid, and (sometimes) the sugar, wine has a built-in preservation system. It handles all the low level threats without human intervention.
We add SO2 to provide a higher level of protection. SO2 addresses oxidation, microbial attacks, etc -- to a point. We protect our wine from the air and other sources of contamination as best we can, so the SO2 has less to do. Think of it as a multi-layered protection scheme. No one layer is perfect, but collectively the protection level is high.
When the wine goes into the bottle, the cork or screw cap seal provide the best level of protection, better than anything prior. We're not opening the bottle until we consume it, so there's no large introduction of contaminants.
While I haven't read this, I'm thinking one value of bulk aging with periodic doses of SO2 is that the duration provides more time for the SO2 to eliminate existing threats, so when the wine goes into the bottle the contaminant level is as low as is possible. It's a normally successful trade-off vs. the dangers of bulk aging. I have no evidence of this, it's just conjecture on my part.
To answer your question as best I can, yes, SO2 can get used up in the bottle. But if the initial contaminant level is low and the SO2 level is high, this will take years.
I do not test for SO2 as I don't see the value. This is not a criticism of those that do SO2 testing -- I believe everyone should do what they feel comfortable with, and besides, my opinion in anyone else's winery means nothing more than they choose to allow it mean. I add 1/4 tsp K-meta / 5 gallons at every racking, and at bottling. My SO2 levels are probably higher than most, but no one (so far) has every complained so I keep doing what I do.
@Rice_Guy posted in the last day or 2, commenting that he maxes SO2 on his fruit wines This makes sense to me, as my experience with organic wineries that use no sulfite is their wines have a crappy shelf life. If you or someone you know has sulfite sensitivity, go light on the K-meta, otherwise don't.
Wine contains contaminants from the crush, more is introduced by various actions. Light and heat affect wine. The SO2 binds chemically to contaminants and renders them harmless. ALL bulk aging containers have flaws, and racking has the potential to introduce contaminants.
Sounds absolutely horrible, right? No one is going to have wine survive the first week!
Nope. Between the ABV, the acid, and (sometimes) the sugar, wine has a built-in preservation system. It handles all the low level threats without human intervention.
We add SO2 to provide a higher level of protection. SO2 addresses oxidation, microbial attacks, etc -- to a point. We protect our wine from the air and other sources of contamination as best we can, so the SO2 has less to do. Think of it as a multi-layered protection scheme. No one layer is perfect, but collectively the protection level is high.
When the wine goes into the bottle, the cork or screw cap seal provide the best level of protection, better than anything prior. We're not opening the bottle until we consume it, so there's no large introduction of contaminants.
While I haven't read this, I'm thinking one value of bulk aging with periodic doses of SO2 is that the duration provides more time for the SO2 to eliminate existing threats, so when the wine goes into the bottle the contaminant level is as low as is possible. It's a normally successful trade-off vs. the dangers of bulk aging. I have no evidence of this, it's just conjecture on my part.
To answer your question as best I can, yes, SO2 can get used up in the bottle. But if the initial contaminant level is low and the SO2 level is high, this will take years.
I do not test for SO2 as I don't see the value. This is not a criticism of those that do SO2 testing -- I believe everyone should do what they feel comfortable with, and besides, my opinion in anyone else's winery means nothing more than they choose to allow it mean. I add 1/4 tsp K-meta / 5 gallons at every racking, and at bottling. My SO2 levels are probably higher than most, but no one (so far) has every complained so I keep doing what I do.
@Rice_Guy posted in the last day or 2, commenting that he maxes SO2 on his fruit wines This makes sense to me, as my experience with organic wineries that use no sulfite is their wines have a crappy shelf life. If you or someone you know has sulfite sensitivity, go light on the K-meta, otherwise don't.
there’s a lot of variables involved with this- as you can see from all the info given after your post ——- BUT
that every 3 months thing sorta goes hand in hand with racking. with the idea that as sediment drops you rack off and add so2 about every 3-4 months. but if you aren’t racking then it’s less of a big deal. if it goes like 6 months or more in bulk without racking i’ll add some. especially if ph is on high side. And FWIW I’ve also had wine age perfectly fine for years without any so2 added at any point.
* My opinion at present is that new rubber corks can be trusted for”normal” storage, cork closures leak and the Nomacork synthetic closures are doctored to mimic natural oxygen leakage.
* SO is “used up” in a circular reaction which reduces higher redox potential molecules
* contaminants, at least the bad contaminants are metal ions, they act as catalysts which oxidize molecules.
* a wine must is an organic molecule mix which contains fairly high energy reduced molecules (ex sugar), ethyl alcohol also contains significant energy. Adding SO2 to our wine delays the oxidation reactions however it is like a wallet when we spend a reduced molecule we can’t get it back.
I don't rack every three months, but I do add kmeta every three months to my carboy.
@Rice_Guy, you exceeded my memory of Chem 101 .... 
I was adamant about racking every 3 months ... but based upon feedback here at WMT, I'm not necessarily doing it. If there is only fine lees, I agree, it doesn't appear necessary. I'm keeping an eye on things, as old habits die hard. But old dogs can learn new tricks.
I felt pretty negligent until @NorCal and others visited with some commercial wine makers who said that home wine makers tend to over-rack.@Rice_Guy, you exceeded my memory of Chem 101 ....
I was adamant about racking every 3 months ... but based upon feedback here at WMT, I'm not necessarily doing it. If there is only fine lees, I agree, it doesn't appear necessary. I'm keeping an eye on things, as old habits die hard. But old dogs can learn new tricks.
Talking to numerous commercial winery owners can be an eye-opener. Home winemakers, as a group, are under-educated and overly paranoid. I count myself in this group, although I try to keep an open mind which is open to learning. Some of our discussions in the past year have been eye-opening.
Cynewulf
Senior Member
There’s a quote I like from one of my favorite winemakers, Matthieu Lapierre, who refers to SO2 as a fire extinguisher: something he wants to have on hand if things go wrong but hopes he doesn’t have to use. Others prefer a proactive/preventative approach. It’s risk tolerance and I reckon everyone has to go with what they’re most comfortable with. Terroir and Technique in Beaujolais: Talking Natural Wines with Mathieu Lapierre | Wine Spectator
Wait, most of us age with an AIRLOCK, not a solid bung. You are aware that oxygen may diffuse through water, right? The water may slow it down, but it does not stop it. Nothing like a cork.
I have moved away from aging with an airlock. I either read it here or dreamed it. I have two batches aging with plastic wrap secured with electrical tape. I assume very little air is making through that. Am I missing some sort of aging magic by not letting a small amount of air in?
If anything, the reverse -- plastic wrap is not necessarily a good barrier. I use vented bungs which let gases out but not in.
I know that it is not letting CO2 out but this wine was 6 months old when I removed the airlocks. Degassed, and clear. Is there a reason I should replace it with a vented bung? Or am I just fooling myself when I think of plastic wrap as a air barrier?
I seem to recall someone posting about plastic wrap being a poor barrier, but can't locate the reference.
For the cost of a vented bung ($6 USD), protect your investment in the wine.
* a typical food plant barrier is a co-extruded plastic composite. It will contain an inner layer as polyethylene which has a low melt temperature and makes an excellent positive seal against glass or PET or metal or HDPE etc etc. There will be other layers which add other properties as oil resistance, oxygen resistance, solvent resistance, CO2 resistance. One of the best barriers is aluminum ie a metalized film or deposited silicate (transparent retorted pouch), both have oxygen transmission rates which are close to zero. All deposited films will have pin holes and we can get away from this by using a thicker layer as aluminum on a ketchup seal.
* Saran is one of the plastic wraps, it is not a good oxygen barrier, it is thin which means the extrusion defects become obvious. On the positive side Saran Wrap stretches therefore we can make a good seal against glass or PET carboys and the mouth is small, another factor is that in aging wine we typically have CO2 which helps protect the wine so all in all Saran isn’t too bad. I wouldn’t use electrical tape to hold it, I would use a rubber band or two.
* silicone is another choice to seal the carboy, your hardware store may have 2” wide rolls of fusion tape (SharkBite underground wrap) or there are cup and bowl covers.
For long term secondary storage with a big mouth bubbler carboy I have placed a saucer over the silicone.
* rubber corks are a good seal for a year or three (old rubber is hard)! This vacuum set up has been running for three months (Feb 11) and dropped from 17.5 in Hg to 9.5 (today),, ask me after a year how well cork and silicone and VacuVin check valve work for sealing a carboy. ,,, (no product in flask)
* driving force is part of storage, my feeling is CO2 is our friend. A 6.5 gallon sister carboy to the above picture of degassed (able to maintain five inches Hg 30 minutes) cyser held a vacuum for a month, ,, likely still had some CO2 bleeding out which equalized the vacuum. On the theory that the ullage is CO2 at equal pressure (no driving force) I consider it safe storage until it is opened up. I kind laugh at folks that want squeaky clean wine with no gas. As noted in other threads I will vacuum cork (like industry folks) and leave some residual gas so the ullage can get filled up with CO2.
* ALL CLOSURES WILL LEAK! some, a metal cap can be rated at 0.1 mg versus natural cork at 4 to. 8.0 mg oxygen per year. ,,, however we can assume the glass carboy or stainless tank walls don’t leak.
* for industrial scale wine the bottling operation is the biggest risk with a typical pick up of 4 to 8 mg O2 per liter, racking to remove SO2 can also be 4 to 8 mg, ,,, home wine makers have larger air to volume therefore we see high risk every time we open up a carboy.
*
* Saran is one of the plastic wraps, it is not a good oxygen barrier, it is thin which means the extrusion defects become obvious. On the positive side Saran Wrap stretches therefore we can make a good seal against glass or PET carboys and the mouth is small, another factor is that in aging wine we typically have CO2 which helps protect the wine so all in all Saran isn’t too bad. I wouldn’t use electrical tape to hold it, I would use a rubber band or two.
* silicone is another choice to seal the carboy, your hardware store may have 2” wide rolls of fusion tape (SharkBite underground wrap) or there are cup and bowl covers.
For long term secondary storage with a big mouth bubbler carboy I have placed a saucer over the silicone.
* rubber corks are a good seal for a year or three (old rubber is hard)! This vacuum set up has been running for three months (Feb 11) and dropped from 17.5 in Hg to 9.5 (today),, ask me after a year how well cork and silicone and VacuVin check valve work for sealing a carboy. ,,, (no product in flask)
* driving force is part of storage, my feeling is CO2 is our friend. A 6.5 gallon sister carboy to the above picture of degassed (able to maintain five inches Hg 30 minutes) cyser held a vacuum for a month, ,, likely still had some CO2 bleeding out which equalized the vacuum. On the theory that the ullage is CO2 at equal pressure (no driving force) I consider it safe storage until it is opened up. I kind laugh at folks that want squeaky clean wine with no gas. As noted in other threads I will vacuum cork (like industry folks) and leave some residual gas so the ullage can get filled up with CO2.
* ALL CLOSURES WILL LEAK! some, a metal cap can be rated at 0.1 mg versus natural cork at 4 to. 8.0 mg oxygen per year. ,,, however we can assume the glass carboy or stainless tank walls don’t leak.
* for industrial scale wine the bottling operation is the biggest risk with a typical pick up of 4 to 8 mg O2 per liter, racking to remove SO2 can also be 4 to 8 mg, ,,, home wine makers have larger air to volume therefore we see high risk every time we open up a carboy.
*
plus @winemaker81 and @sour_grapes
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