Why sulfate with every rack?
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Intheswamp
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An 1/8 tsp will be a big plenty. 1/16 tsp would probably be enough. Many people feel that adding k-meta at every other racking is sufficient and prevents a large buildup of sulfites in the wine.
But if you sanitize with a K-met, why does it also need to be added to the wine when racked?
BTW, when you say 1/16th, is that for all 6 gallons or per gallon?
Thanks!
Why did the surfer wear two condoms when he had sex? So he could be ‘fer sure, ‘fer sure!
Sorry - it’s a dumb old, high school humor, joke. But it’s the first thing I thought of when you asked the question.
It’s all about prevention. Commercial wines have substantially higher sulfites to ensure against oxidation and bacterial growth. We’re talking 70% higher levels of SO2 than what you’ll find in a wine a home brewer would add.
Sanitizing your carboys is huge. But it is not be enough to protect the six gallons of wine in the carboy from time and the possibility bacterial growth. Bacteria is life... and unless there’s enough SO2 in your wine, life eventually finds a way.
I’m really not sure where all of these 1/8 and 1/16 tsp per racking are coming from, but let’s set the record straight.
Sulfite levels should be maintained to protect wine from both oxidation and organic invaders. The minimum sulfite levels are a function of the pH and color of the wine, the lower the pH, the less sulfite it takes, and visa versa. White wine needs more sulfite than red.
Sulfite gets “used up” in wine as it scavenges oxygen and protects your wine, some becomes “bound” and some gets used up, it’s why we have to maintain sulfite levels, and how fast it gets used is based on the wine itself and how you handle it.
Properly administered sulfite protocol says that sulfite levels should be checked on a regular basis, and adjusted as needed to maintain adequate levels of protection. Not everyone is willing to invest the money and time to do this testing.
This is where the “rule of thumb” has been applied, which is to use 1/4 tsp of potassium metabisulfite, per 6 gallons of wine, every three months. This doesn’t work for wines in barrels, which may require more frequent application. One doesn’t need to add sulfite at every racking, every three months is fine unless you expose your wine to excessive amounts of oxygen.
If you want to maintain your sulfite levels as low as possible, invest the time and money into the testing equipment, and you’re off to the races. I wouldn’t advise that anyone summarily cut their dosage from 1/4 tsp / 6 gallons / 3 months down to 1/16 tsp without testing. Just my opinion.
Sulfite levels should be maintained to protect wine from both oxidation and organic invaders. The minimum sulfite levels are a function of the pH and color of the wine, the lower the pH, the less sulfite it takes, and visa versa. White wine needs more sulfite than red.
Sulfite gets “used up” in wine as it scavenges oxygen and protects your wine, some becomes “bound” and some gets used up, it’s why we have to maintain sulfite levels, and how fast it gets used is based on the wine itself and how you handle it.
Properly administered sulfite protocol says that sulfite levels should be checked on a regular basis, and adjusted as needed to maintain adequate levels of protection. Not everyone is willing to invest the money and time to do this testing.
This is where the “rule of thumb” has been applied, which is to use 1/4 tsp of potassium metabisulfite, per 6 gallons of wine, every three months. This doesn’t work for wines in barrels, which may require more frequent application. One doesn’t need to add sulfite at every racking, every three months is fine unless you expose your wine to excessive amounts of oxygen.
If you want to maintain your sulfite levels as low as possible, invest the time and money into the testing equipment, and you’re off to the races. I wouldn’t advise that anyone summarily cut their dosage from 1/4 tsp / 6 gallons / 3 months down to 1/16 tsp without testing. Just my opinion.
Intheswamp
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My suggestion of 1/16 tsp was for a single gallon...I flew right past the "...or will that be enough for..." part. I'll crawl back under my rock now... 
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My suggestion of 1/16 tsp was for a single gallon...I flew right past the "...or will that be enough for..." part. I'll crawl back under my rock now...
LOL!! No need for rock crawling, we all misinterpret posts at times, my concern was solely for the safety of the wine of the OP, or anyone else who came along and read the post. The truth is, that if you keep your 6 gallon carboys well topped, under a good airlock, in a cool environment, and don't open them much, the 1/4 tsp can be a little heavy handed for a wine with low pH. But, and there's always a but. this is just a rule of thumb, designed to keep wine safe in most reasonable conditions, and in the absence of actual testing and adjustments based upon actual sulfite levels.
Though I have SO2 testing capabilities, I don't test very often, opting for the "rule of thumb" during bulk aging, usually only testing and making precise adjustments just prior to bottling.
NorCal
Senior Member
@Johnd hit on all the points. Seems like all answers in winemaking and poker, the answer is that it depends.
The rule of thumb of 1/4 tsp (1.6 grams, 50 ppm / 5 gallons) works for kits, which come with acid pre-adjusted in the 3.5 range, made in the carboy and bottled in under a year. I have the equipment and if I were making a kit, I wouldn’t even break it out to test the wine. Why? Because the total SO2 would be 200 or less and I know the free SO2 would be well above what is needed to keep the wine safe in the bottle and well below the sensory level.
It is when you are dealing with fruit directly from Mother Nature and vessels that by design expose the wine to oxygen, that one has to monitor the situation. I made the same wine and had it in a barrel, in a flex tank and in glass. When the barrel needed 40 ppm, the flex needed 20 ppm and the glass only 10 ppm. If I have fruit in the 3.5-3.6 range, I will only measure once or twice because I know the free SO2 will be in the safe zone and total SO2 will be well below my sensory threshold hold and what the government say is the maximum allowable (350 ppm total SO2).
I invested in the meter because the fruit I deal with tend to be high pH, 3.7 - 4.1, using barrels and aging for 12-18 months. The rule of thumb does not apply and would leave my wine exposed.
The rule of thumb of 1/4 tsp (1.6 grams, 50 ppm / 5 gallons) works for kits, which come with acid pre-adjusted in the 3.5 range, made in the carboy and bottled in under a year. I have the equipment and if I were making a kit, I wouldn’t even break it out to test the wine. Why? Because the total SO2 would be 200 or less and I know the free SO2 would be well above what is needed to keep the wine safe in the bottle and well below the sensory level.
It is when you are dealing with fruit directly from Mother Nature and vessels that by design expose the wine to oxygen, that one has to monitor the situation. I made the same wine and had it in a barrel, in a flex tank and in glass. When the barrel needed 40 ppm, the flex needed 20 ppm and the glass only 10 ppm. If I have fruit in the 3.5-3.6 range, I will only measure once or twice because I know the free SO2 will be in the safe zone and total SO2 will be well below my sensory threshold hold and what the government say is the maximum allowable (350 ppm total SO2).
I invested in the meter because the fruit I deal with tend to be high pH, 3.7 - 4.1, using barrels and aging for 12-18 months. The rule of thumb does not apply and would leave my wine exposed.
1/8 tsp. per carboy (6 gallons).
It's 1/4 tsp per 6 gallon carboy..............every 3 months.
Scooter68
Fruit "Wine" Maker
Every bottle of K-Meta I've seen states 1/4 tsp per 5 or 6 gallons. That 5 or 6 is the only variation I've seen.
My batches are 3 gallons so I use 1/8 for them which follows the recommended regime. I rack every 3 months and add K-meta at each racking.
When you cut corners you need to have a sound basis for what you are doing (Equipment to do the right testing) Other wise you are hanging it out in the breeze.
1/16 tsp per gallon does not match the recommended dosage. Those doing 1 gallon batches would do better to simply buy Campden tablets which are pre-measured for 1 gallon.
My batches are 3 gallons so I use 1/8 for them which follows the recommended regime. I rack every 3 months and add K-meta at each racking.
When you cut corners you need to have a sound basis for what you are doing (Equipment to do the right testing) Other wise you are hanging it out in the breeze.
1/16 tsp per gallon does not match the recommended dosage. Those doing 1 gallon batches would do better to simply buy Campden tablets which are pre-measured for 1 gallon.
Intheswamp
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No problem about the rock...I'm on a first name basis with all the spiders that live there.
I'll be doing 1-gallon batches and an occasional 3-gallon batch...those are the biggest sized carboys that I have. So I'll be working with smaller quantities of K-meta. From a couple of places I've found it stated (don't know it for a fact) that 1/4 tsp of K-meta weighs pretty close to 1.4 grams. Since the general "rule of thumb" is for 1/4 tsp for a 5-6 carboy I'll calculate the dose for 5.5 gallons.
This comes out to about .25 gram per gallon. Sound about right for a rule of thumb?
NorCal
Senior Member
I suspect it depends on the kmeta you are using. I weighed the brand I use and mine closer to 1.6, but regardless, 1.4 - 1.6 is close enough.No problem about the rock...I'm on a first name basis with all the spiders that live there.
I'll be doing 1-gallon batches and an occasional 3-gallon batch...those are the biggest sized carboys that I have. So I'll be working with smaller quantities of K-meta. From a couple of places I've found it stated (don't know it for a fact) that 1/4 tsp of K-meta weighs pretty close to 1.4 grams. Since the general "rule of thumb" is for 1/4 tsp for a 5-6 carboy I'll calculate the dose for 5.5 gallons.
What I've seen is people using 1 campden tablet when racking 5 or 6 gallons, and using the 1/4 tsp when it's going to just sit and age.
So say for racking a 5 or 6 gallon carboy, if one just sanitizes with P-Meta, shouldn't the be sufficient? As in no additional K-Meta needs to be added, since you'll have some in the carboy from the sanitization?
So say for racking a 5 or 6 gallon carboy, if one just sanitizes with P-Meta, shouldn't the be sufficient? As in no additional K-Meta needs to be added, since you'll have some in the carboy from the sanitization?
There will be nowhere near enough residual KMeta left from sanitizing.
GreenEnvy22
Senior Member
No, the residual amount left on the surface of the carboy after sanitizing is next to nothing. 1/4 tsp k-meta is about 1.6g. That will raise your sulfites by about 50ppm above whatever they are now. I wouldn't be adding that much each time I rack, probably half that. However I test my levels after racking and add as much as needed. Like John said it varies with pH, but I generally aim for about 30ppm while being stored.
* When I have tested sulphite I have seen that whites will have zero to a trace of sulphite. Testing reds I will find measurable sulphite 20, 30 ppm. As a quick and dirty if I look at a white or country wine I assume that it is close to zero ppm.
* Yes sanitizing does have some sulphite, now if I ran the numbers I would guess half a milliliter of sanitizer after a carboy drained times X ppm diluted to 5 or 6 gallons, the Vinmetrica probably wouldn’t detect it.
* We are dealing with a small system, the effect of a leaky cork or airlock or bad technique is greater than if I diluted out in a 1K or 10 K plant tank.
* I can pasteurize a juice and create a commercially sterile product. Fine for microbiology BUT wine at 11% alcohol and pH 3.5 is already a low microbiological risk food. The factor that determines shelf life is oxidation. If you try an organic country wine it will probably have significant burn on the back of the throat (acetaldehyde/ oxidized ethyl alcohol) or sherry like flavor. , , , Reds have antioxidants from the skin so a red might be drinkable.
* Judging country wine at state fair about 2/3 have oxidation. We as a tribe are fighting oxidation, , , at least as long as we have a breathable atmosphere in the winery. SO2 is just removing The breathable atmosphere inside the glass carboy.
* Yes sanitizing does have some sulphite, now if I ran the numbers I would guess half a milliliter of sanitizer after a carboy drained times X ppm diluted to 5 or 6 gallons, the Vinmetrica probably wouldn’t detect it.
* We are dealing with a small system, the effect of a leaky cork or airlock or bad technique is greater than if I diluted out in a 1K or 10 K plant tank.
* I can pasteurize a juice and create a commercially sterile product. Fine for microbiology BUT wine at 11% alcohol and pH 3.5 is already a low microbiological risk food. The factor that determines shelf life is oxidation. If you try an organic country wine it will probably have significant burn on the back of the throat (acetaldehyde/ oxidized ethyl alcohol) or sherry like flavor. , , , Reds have antioxidants from the skin so a red might be drinkable.
* Judging country wine at state fair about 2/3 have oxidation. We as a tribe are fighting oxidation, , , at least as long as we have a breathable atmosphere in the winery. SO2 is just removing The breathable atmosphere inside the glass carboy.
This is 0.19 gram of K meta, the amount I would add per gallon of must. I use roughly 0.095 gram/ gallon at racking to add 25 ppm.
Scooter68
Fruit "Wine" Maker
The presence of sulfites from sanitizing is to be zero if Star San is used to sanitize.
That I get, but I've been using a K-Meta solution for wine making...
Do you think 1/8 tsp (aprox 1 gram) of K-Meta will fine for racking 5 or 6 gallons and when it's finished use the 1/4 tsp?
My Pinot Grigio is in the secondary fermentor and it's bubbling the airlock, so I have some time to figure this out..
BTW, you guys have me worried about SO2 testing now. In the past, I always thought you didn't want sulfates in the wine, but based on what I'm hearing from you all, it's looking like it not only needs to be checked, but regulated too.
Thanks!
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