Potassium Metabisulfite vs Potassium Sorbate
Vložit
- čas přidán 15. 07. 2024
- Support on Patreon, and unlock exclusive content: / makewine
www.smartwinemaking.com
Potassium Metabisulfite and Potassium Sorbate are commonly used additives for winemaking, but what is their purpose? In this video, I will explain the purpose of each as well as when to use them and when not to use them. - Jak na to + styl
seriously, you are the best and most informative youtuber about winemaking. love your content
Excellent info, very informative.
Very good review of chemicals.
Great video, thank you.
I blow a lot of Ganja smoke around my carboy before bottling ! Keeps away the evil spirits from those who cant handle the wine !
Wow..
My friend's pet got addicted , and now he wants the smoke getting straight into his nose.
Wow! Thank you for sharing! Such good information!
Some good info here.
I'm a mead maker and this video is very helpful. I am also trying to grow grapes. I just peaked at your website. How did I miss this?
Great Video. So this year I intend to press 500kg of Syrah grapes. I know that the grapes have been treated once with sulfite. How much potassium Metabisulfite approx do you suggest adding. I'm afraid of having that sulfite smell. Thanks
This was in my CZcams recommendations
My only experience with wine making is a microbes class I took last year
This was amazing
great info.
Tnx for the info
thx great video :-)
When do you add potassium metabisulfite? When does alcoholic fermentation end? Also do you add clearing aid like DualFine before or after potassium metabisulfite. Also how many days before or after? Do I even need DualFine or does metabisulfite also act as a fining agent/clearing aid?
I plan on making wine for the first time, and I'm leaning towards a Merlot or a Shiraz from fresh grape juice. I keep finding conflicting information on this, and I was hoping you could answer some questions for me. First of all, how long after the primary fermentation can the wine sit before racking? Secondly, how often should I be racking? Also, should I be adding Potassium Metabisulphite each time I rack, or is that only required for the bottling process? Lastly, I prefer to bulk age, how long should I do so before bottling
Hi there. Once dosed into tank (I’m using sodium metabisulfite) how long can it stay in the tank before packaging? Indefinitely? Cool vid. Thanks.
Thank you sir 🙏
Hi my fermentation barrels ( x4 )hold 180 litres approx. When adding sulfites to control bacteria and wild yeast before primary fermentation at a rate of 50ppm should that be calculated on the basis of the whole must (i.e. incl. skins) at 180 litres or the estimated quantity of juice? Thank you
After second fermentation my wine is dry , I added recommended sulfites to my wine but no sorbates, what will happen if i added a sweet wine thats stable with sulfites and sorbates ? Will it try to ferment again?
Great. I added Potassium Sorbate plus Sodium Metabisulphite to my 6 gallons of blackberry wine. Wine has been in the secondary 2 weeks. Should I syphon wine off sediment again now or wait?
Great info! You mentioned using potassium metabisulfite with each racking ... if not testing free SO2, how much can be safely added each time and still provide adequate protection for the wine? 1/8 tsp per 6 gallons?
im wondering if you could use wine to dissolve the metabisulfite , my friend went to wine school and they said always use water as it shocks the wine. do you have any scientific reason wine would get shocked and what would be the consequence?
Love your videos... A friend of mine and I just discovered your videos and website yesterday.. and you've already have had lots of influence on us. I have 5 -5 gallon grapes that I just started primary fermentation. I used 5 campden tablets in each at the start, waited a day and introduced the yeast yesterday. So hear's my desperate question. Is it too late to add the Potassium Metabusulfite? Would it kill all of the yeast I just added? Any suggestion would be much appreciated... Thanks Dave
Thank you! If you added Camden tablets, it will achieve the same thing as the potassium metabisulfite. Camden tablets are usually about 500mg of either potassium metabisulfite or sodium metabisulfite. I wouldn't add any more than you have already added until after primary fermentation or after malolactic fermentation if you intend on allowing it to occur.
@@TheHomeWinemakingChannel Thank you very much. Just to confirm, by using the amount of Campden tablets I used (5 for 5 gallons) I haven't lost the opportunity of the wine moving into malolactic fermentation once primary fermentation had finished.
Question though is potassium sorbate completely stop repeat fermentation and does cold crashing also completely stop Refermentation ?
Hi, my wine goes acidity. How can I fix it? I am planning back sweet it, and use potassium sulfite. Is that OK
Hi, so I am planning to bottle my mead next Saturday, I am planning on adding bentonite a day before to clear it as it is quite cloudy, and then I was thinking of adding the potassium sorbate and potassium metabisulphite the next day, leaving it a few hours and then bottling/consuming. Is this okay? I'm not planning on back sweetening.
I’d add the metabisulfite first and bentonite last. I personally clear last, although I don’t think one day is sufficient for clearing if it’s cloudy.
Great advice! How much potassium busulfate do you typically add to a six gallon bucket of juice to start and then after the first racking? I try to limit it so was curious what your advice is. Thanks!
It is a little bit of a guess if you aren't running a sulfite test since you don't know how much they have already sulfited the juice. I would generally say none or maybe 1/8tsp which would be about 25ppm. If you know it hasn't been sulfited you can give it a little more. If you make a really strong yeast starter, it should help alleviate the risk of another bad yeast or bacteria dominating the fermentation
Cool! Thank you
If I'm making mead and plan to back sweeten when would I add both of these potassiums? I will be racking into a separate container to back sweeten.
Guess he doesn't reply to people
Sir, can I use potassium sorbate for pickled papaya?
I´m planing start to homemade some wine. I live in a cooler part of Brasil. I have access to some crops around here but the question is: any kind of grapes can be fermented and give a reasonable good wine?
You can make wine out of just about any grapes, but it might not be so good. In the colder regions around here they mostly grow Concord and other grapes in the Vitus Labrusca family. Most of those will make wines with a very fruity, grape juice like taste. They make french-american hyrids that do well in colder climates and make slightly more premium wines. Some examples would be Marquette, Traminette, and Noiret. Cornell University is big into creating these hybrids. Most premium wines will come from Vitus Vinifera grapes, which is pretty much any grape wine people would know by name. Some of the more cold tolerant white vinifera grapes would be Riesling and Gewurztraminer. For reds, Cabernet Franc, and Pinot Noir do okay. Cabernet Sauvignon is relatively cold tolerant but is late ripening, so people have trouble ripening it properly in colder climates. I would see if you can source grapes from Chile or Argentina. Good Luck!!
Thank you for the advice. I will find what species they grow around here and then I´´ll post here
I recently added both of these to my strawberry wine so I could back sweeten. The wine was VERY clear when I added and after adding I stirred real good and let sit overnight and went to back sweeten the next day. There was junk floating all inside all 3 gallon jugs. Not on top but throughout like suspended. I let it sit for about 3 weeks and some of it settled but much of it was still suspended. I painstakingly filtered through cheese cloth and then coffee filter. I then pasteurized so I could back sweeten. Can you tell me what may have went wrong when I added the sorbate and sulfite? Someone suggested that I may have stirred it to much but I am looking for other thoughts. Can you help? I am reluctant to ever use them again before bottling but know I need to. Thank you
It most likely grabbed on to a foreign bacteria that was weak. It may have stopped you from getting sick. Or just doing its job of capturing the yeast and killing it. . Not sure. Have you any more ideas sir? Thanks for posting.
Hi, i am relying on wild yeast in grapes to process the fermentation because I don’t have access to any commercial wine yeast right now, if i use Potassium Metabisulfite is that will kill that yeast ?
Thanks,
will kill wild yeast
Hi
How many gram of p.sorbat i need to put in sweet wine
To 100 liter?
Thenks
Good info. Started making wine 2 years ago mostly with the cheaper kits. The starting SG on the these kits are around 1.080 resulting 10-11 ABV I would like to get ABV 12-14 Should I add inverted sugar to achieve this? Have you done this yourself and what where the results. Thanks.
I have added invert sugar with pretty good results. Even better though is to make 5 gallons from a 6 gallon kit. That will bring up your sugar right where you want it, drop the pH a bit, and concentrate the flavors. If you want you can add potassium bicarbonate if your pH drops too much but I usually don't have to.
Thanks, I will try both methods.
After 21 days can I add potassium meta bisulphate to the wine quantity is 3 litres--milli grams of potassium for 3 liters
If I filter my wine kit, after the sulfite and sorbate is added…. I do this because I hand these out as gifts and I want zero sediment in the bottles… do I remove the sulfite?
Do you have to let the wine sit for a couple of hours after adding the sorbate and metabisulfite before you start adding sugar when you are ready for bottling?
From what I have seen, it seems recommended to add the chemicals and wait 24 hours before adding any sugar.
I mistakenly add potassium sorbate in the beginning of my pomegranate mead .
What can I do? I just when to add another EC 1118 to the wine when I realized my mistake.
Hi! May I ask what is the difference between sodium metabisulfite and potassium metabisulfite?
I want ask the same
Me too!
u use potassium sorbate to stop a only sweet wine from refermenting
u use potassium metabisulfite to keep your wine from oxidation
Hello sir,
My red wine was fizzy and the yeasts were still alive
I added potassium sorbate and potassium metabisulfite to the wine
But the yeasts are still alive!
I want to try the pasteurization method...
I wanted to know according to the ingredients I added wine,Potassium sorbate and potassium metabisulfate
If I heat the wine for pasteurization
Do these materials show a dangerous reaction?
I would be grateful if you answer♥️
I want to back sweeten my wine and have it naturally carbonated a good amount, but not to the point of bottles blowing corks- How do I do this?
I have 3kg grapes i add 2 litres water so how much grams potassium metabisulfite to add last time I faceing the ph problem plz help me sir
so if sorbate wont kill the yeast that has not died what is the point of using it if you are not able to back sweeten? is there a period you need to wait for the yeast left in to die after adding sorbate before you sweeten?
A yeast cell can only ferment for so long before fizzling out but the problem is that they are normally "culturable". In favorable conditions a single yeast cell will multiply many times over and each of those new cells will do the same. A few hundred cells can turn into a few billion pretty quickly which is enough to now appreciably ferment the wine again whereas a few hundred really isn't. The sorbate prevents this by preventing the cells ability to 'bud" and multiply. If you have a cloudy wine with a high cell count it is pointless and the wine will still ferment again. That's why in the video I reference that the wine must be crystal clear and racked off of the lees before adding sorbate. For reference, those lees settled out the the bottom of your wine can contain around 3-10 billion yeast cells per mL. It's incredible...
@@TheHomeWinemakingChannel yes that is what i learned, it needs to be fairly clear after enough racking this way there are very little residual yeasts left if not dead and therefore adding the sorbate just before back sweetening or during will ensure no more fermentation ,now this is fine and good for a base wine but suppose you want both carbonation and sweetness in the bottle? i would think for beers or sparkling wines etc with a sweetness you need to add the sugar but then pasteurize to ensure you end up with a sweet fizzy product in the bottle correct? or will some sparkling wine makers add both sugar and sorbate after disgorging to do this trick? i heard they only add sulfites but im sure both need to be added if not at least the sorbate
Great video!
What is the best for adding to limejuice out of both as a presavative?
Bummer that he doesn't reply
How to use metabusulfite, is it dissolved in water or direct
We home brew Mead and I think I’m one of the only people I know who doesn’t use potassium Sorbate at all. We use potassium metabisulfite after fermentation since it’s a preservative and will also stabilize. I’ve backsweetened after and never had any issues.
Hey Stacie, I read your comments on this thread and you do seem knowledgeable. I could really use some insight. I can run a wine dry no problem and not worry about bottling and so forth. But I'm working on this sweet strawberry wine and I'm wanting to stop fermentation with an ABV of 12 and leave just a little bit of the sugar. At which time I would add metabisulfite and sorbate to stop fermentation and then the bentonite. If you got time I would like to hear your thoughts on this. Thanks!
@@blakeoblko852 I would add the metabisulfite after about a week or when your ABV is where you want it. Then add bentonite to clear. You can always back sweeten. We’ve made mead a few years now
How does it compare to sodium metabisulphite?
Ive got some juice with potassium sorbate in it. Its also got sodium hexametaphosphate... I usually use preservative free juices but had this laying around. Will it will ferment with this junk in it? Just wondering before I waste my yeast. Reply appreciated! Cheers.
It probably will not ferment, and if it does, the yeast will be stressed and can make off flavors. Id probably save your yeast for another juice. Most frozen concentrates are good to go but many that are sold in bottle have too many preservatives to keep them fresh.
@@TheHomeWinemakingChannel Aw alright. I kind of knew better but I guess since im a home brewing newbie I wanted to give it a try against my better knowledge. Thank you for giving me helpful info friend. Going to give you a sub now. =)
I have a couple questions but I see a lot of unanswered questions. I hope I get a reply from you. One of the reasons that I prefer a good homemade wine is that there are no sulfites in it....usually. I had a small glass of my very first gallon of wine that I made. No potassium sulfites at all and no hives. No wheezing. I am afraid to add the potassium metabisulfites because I am allergic to sulfites in wine. Is there an alternate thing one can use in its place? Potassium sorbates....are they worth using??
Thanks for your time.
Hi, it is possible to make wine without the use of sulfites but you are generally adding a lot of spoilage risk and would want to consume the wine within about six months. If you are working with a kit or pasteurized juice instead of fresh grapes it is a lot more do-able but you are a little more limited on the peak quality you can achieve. I would first verify that it is indeed the SO2 (sulfite) causing the reaction. SO2 is often unnecessarily blamed for headaches and reactions to wines. Wines that have undergone malolactic fermentation (as most commercial red wines have) will contain close relatives to histamine like tyramine and histadine. White wines contain substantially more SO2 and dried fruits are waaaaaaay higher in SO2. You can setup a simple trial by adding about 50ppm of SO2 to a juice to see if the same reaction happens. No need to make Winemaking harder on yourself if not necessary! Winemaking sulfite free makes the wine much more likely to create acetaldehyde which is a carcinogen and worse than the miniscule sulfite dose if I were to rate them. If indeed it is the histamine causing the problem you could either forgo MLF or choose a low histamine MLF strain like Christian Hansen CH16. Back to your first question... If you want to make wine sulfite free I'd focus more on it being sulfite free at the time of consumption. Sulfites rapidly oxidize and bind with components of the wine over time. If you measure with using either the aeration oxidation method, titrets, or a vinmetrica tester, you can assure that the wine is below about 25ppm free SO2 at the time of bottling. This will drop to about 10-15ppm after the O2 exposure of bottling which is about as close to nothing as you would want to be. Other key factor for making a low or no sulfite wine is to to have a high redox potential. This is achievable if you encourage high tannin, low pH, and lower O2 exposure during fermentation and no O2 exposure during aging into bottling. Potassium sorbate is only useful if you want to retain residual sugar in the wine. It prevents re-fermentation as long as your yeast cell count is low but does not prevent oxidative spoilage. Hope that helps!
@@TheHomeWinemakingChannel WoW!! That's a LOT of useful information!! Thank you so much!! I will experiment for certain, just to make sure which is giving me the histamine reaction. Thank you for taking the time to explain all of that. Its very much so appreciated. Hope you have a great day!!🍷
After adding campden to wine while bottling. How soon can I drink this?
Right away if you want!
I got 0.1% of potassium sorbate in my aloe Vera juice, is it safe?
Can I stabilize with ONLY Sorbate??
At what time will I add both of these?
Personally, I add the large amount of potassium metabisulfite after fermentation is complete and small amounts when racking to accommodate any oxygen that was introduced while racking. I add sorbate when back sweetening, so the sorbate/metabisulfite wait 24 hours - 48 hours, then back sweeten. I leave the wine a couple days after to make sure it doesnt start to referment, then bottle.
I dont care if they are good or bad for wine, I care if they're good or bad for me to ingest!!!
Preservatives are definitely a tricky sell sometimes but probably better than the alternative depending on your perspective. Sulfur dioxide (SO2/sulfite) is actually naturally formed by yeast but readily binds and oxidizes away. it is also responsible for the smell when you strike a match. In a way, by adding a miniscule dose of SO2, we are just replenishing what was there as it goes away. By doing this, we can hijack nature and pause the decomposition cycle in the tasty wine phase rather than allowing to continue forward towards vinegar and other natural but unwanted compounds. Without sulfite you will eventually get substantially more acetaldehyde which is a carcinogen. It is what your liver creates when it cant process the alcohol fast enough and is very bad for your heart. It is also a key component of port and sherry and responsible for the distinct nutty smell. You will also get ethyl acetate which is the nail polish remover smell that a lot of homemade wines can get. Also not a great thing to invest. A lot of crazy natural chemistry happens in wine!
What is the diff between Sodium meta va potta meta??
I've read that filtering your wine will remove any yeast. Is that true?
If it is a sterile filter (.5 micron or less). It is very hard to achieve true sterile filtration in the home though. It is much more reliable to use potassium sorbate if sweetening. If you are making a dry wine, as long as it is properly sulfited and malolactic fermentation has completed, filtration will usually do more harm than good. You really want to make an environment that is low nutrient, high acid, high tannin, high alcohol, and low oxygen to inhibit microbial growth (some combination usually does the trick). Which is pretty easy to do in wine if think about it a bit.
any idea why my pink fruity must turned into light brownish color after adding Camden tablet? i added 1 CT to 4 liters . the pink color is all gone now.
There is a temporary bleaching effect at higher doses of SO2. Happens to every red wine must when you sulfite it before fermentation. Should come back in a day or so. Is there fruit in the must or is it just juice?
@@TheHomeWinemakingChannel juices from home slow pressed juicer (mixing white and some red grapes) . You think 1 camden tablet is alot for 4.5 liters of juice? thanks for you quick reply i really appreciate it.
One camden is appropriate for that much juice. The pink anthocyanin pigments will specifically bind with SO2, revealing any brown unsettled particles.
What does this chemical do in Grape Juice?
when do you use each of the agents? like how do you choose which one to use for red and for white?
I'm sorry according to my bad english and i confused, i couldn't understand, may anybody explain to me easy way ?
can you use kmbs to sanitize bottles?
You can make a solution of citric or tartaric acid and kmbs to sanitize. It works well but will burn the nose pretty good if you accidentally catch a whiff. It will also often create crystals which can clog spray bottles. I much prefer starsan which is about as cheap if not cheaper once mixed up.
Good day sir. How to use potassium sorbate in kalamansi juice or lemon juice?
You will want to use it after fermentation is complete and when you add sugar back to slightly sweeten the wine. Also add potassium metabisulfite at this time. Add 3 two potassium sorbate to 6 gallons and 1/4 tsp potassium metabisulfite to 6 gallons. If you have a pH meter you can be a little more precise on your sulfite amount but you should be fine with 1/4 tsp as long as you don't plan to age it for years.
@@TheHomeWinemakingChannel thanks sir
Hello nice video! I need some serious advise, I bought a wine kit from Artful Winemakers, it’s amazing ,then I couldn’t find their site, so I bought a wine pack from Wine Lovers. Now the Artful winemaker makes 12 bottles , the problem is I utilized the kit as if the grape package made 12 bottles but the Condensed wine from Winelovers makes 30 Bottles. And I messed up, it’s sooo sweet n thick, I need to pour more water in, but will I have ruined the batch if I do this, how can I improve my Wine and get it bottled . Sorry so much trying to break it down ..not easy. Please hoping someone can help me..Thanks 😊😗😱
If you have not added the potassium sorbate yet, you can just add additional water, and pitch a new packet of EC1118 yeast. The fermentation probably just stalled out since there was an extreme amount of sugar which will create enough alcohol to render a yeast ineffective. If you have added the potassium sorbate, it will be a much bigger struggle to get the fermentation going. You may be able to with a huge yeast starter. If you have added the potassium metabisulfite, you will want to give the wine a little air. The sulfites will react with the air which will reduce the SO2 back to a level that the yeast can handle. If you did use the potassium metabisulfite, you will want to get a small container of it and add 1/4tsp at the time of bottling to protect the wine from oxidation since you will intentionally oxidize away what you have already added.
The Home Winemaking Channel wow I’m so glad to hear from you.. so 8 did add the potassium sulfate. And I only have 12 bottles so to make 30 how much water should I used and so I should us3 another container.bottle and yeast mix half & half times 2 ?
I dont have this,.can.i make wine.without this?? or What i use without this this?
My wine is tasting and smelling a little like vinegar, can I fix this?
Not usually. If it is very subtle you may be able to blend it with another wine but most likely it will just ruin the other wine. You can also add it to an actively fermenting wine which can reduce the vinegar back to ethanol but that is also a little risky. I once tried that and added about 20% to an active fermentation. It cleared to up the acetic acid but it created a biproduct, isoamyl acetate in the process which smells like artificial banana. Luckily that is even more volatile than vinegar so over time and with proper SO2 levels it eventually went away.
how and when does malolactic fermentation begin?
MLF is initiated by bacteria naturally present on grape skins. The bacteria consumes malic acid and outputs lactic acid which is much smoother. It generally starts near the end of alcoholic fermentation and can take up to a couple months to complete. If you are not using fresh fruit you will need to add the bacteria to initiate it (if you want to). For most white wines and fruit wines it is best to prevent it. For most skin fermented red wines you will want to encourage it.
@@TheHomeWinemakingChannel ahh so it is encouraged for red wines then? but i heard if a wine has enough acidity or alc it will inhibit malo formation is this true? also to stop it from happening you can add sulfate to the finished product or pasteurize correct?
How many grames of potassium metabisulfite can we add in 1L?
Did you find the answer?
I add pottasium metabisulfite before Fedamentation and then waiting 24 hours then I add yeast but bubbles not coming , what is the problem 🙄
How to stop pottasium metabisulfite formula to boil my wine
What does Metabisulfite do in grape juice?
It is often in store bought grape juice as a preservative. The potassium metabisulfate helps prevent oxidation and has some anti microbial effects. The potassium sorbate prevents any rogue yeast that may have gotten in there from starting a fermentation.
I'm from INDIA and me and my friends are planning to make wine that could last for 20-25 years so that we can open it in that period, so that our friendship will be stronger with that wine. for achieving that period, is there anything to do something else. Kindly Rectify my doubt. Thanks
That is ambitious but possible. You will need very high quality grapes with good acid. If your pH ends up above 3.6 it probably won't make it, so you are probably going to want to start with grapes around a pH of 3.25 (will finish around 3.5-3.55). They should still be ripe though, dark purple/black and brown mature seeds. 25 to 28% sugar in the grapes to produce 14+% alcohol. I would use the saignee method and pull off some juice after crushing to provide a good strong skin to juice ratio. Use fermentation tannin or oak during fermentation to try to bind up any tannin in the skins. You will probably want press it pretty hard to extract a lot of skin/seed tannin. Oak it pretty hard for yet more tannin. At about a year it should taste pretty intense and harsh still if you are going to have a shot. Sulfite with at least 50ppm free SO2. Use the highest quality natural corks. They will be expensive but you will need them. Store the wine on the side in a cool cellar that is ideally less than 60F and without temp fluctuation. If you do all those things you might make a crazy amazing wine. I would suggest trying a bottle once a year though so that if it peaks past it's prime you will have some heads up and can enjoy it before it falls flat or oxidizes negatively.
@@CoolStuffGuysLike Thankyou, Then we ill try make 20-25 bottles and take out every year. Same time produce single batches every year rectifiying mistakes.
would camden tablets be an recommended alternative to use instead of either of the above chemicals to control bacteria?
sorry, question answered in video
Those packets look like they come out of a Winexpert kit.
I would like to make a gallon of Strawberry Wine could you tell me what I need to put in it and what to do can you comment that to me Cajun van Church Point Louisiana
why not to go to any of the winemaking websites? There are many out there, and you can get overviews of the winemaking process, detailed instructions, tips on equipment, techniques and additives, as well as exact recipes for many different wines. Everybody's gotta start somewhere, and these people know their stuff.
Both are food additives/preservatives with side effects.
Can you teach me making perfect wine?
what about sodium benzoate ?
Benzoic acid are not very effective in inhibiting yeast
I ordered Lodi Ranch 11 cabernet sauvignon California from Winexpert for $179, from their label information it added 10 wt% sugar in this juice after you received it, but California state prohibits chaptalization. I will not buy any from this company.
Pueden explicar en español😊
you dude. fo have facebook page.
Wrong
why are you talking in parts per million , that is not something 99% of the planet can measure , how about how many teaspoons to 5 gallons ? need to stop the ferment in my mead ive gone from 1090 to 1010 and its still fermenting but its close to stopping , im guessing another week and it will be 1000 with zero sweetness left so i need to make sure its finished before i back sweeten (my first time brewing )
PPM is the norm for a lot of wine measurements because the amounts are so small. If you don't have a scale, 1/4 tsp of k-meta is about 2 grams so it works out to about 50ppm of free SO2 for 6 gallons or 60ppm for 5 gallons. That is right in the ballpark where you want to be. Really it is dependant on your pH but as a beginner, target about 50ppm and as long as you aren't aging for 20 years or way low on acid you will be okay. For potassium sorbate, 1/2tsp per gallon if you are sweetening. Don't use old stuff! Potassium metabisulfate oxidizes very easily and will lose effectiveness if not stored in a sealed container and cool.
excellent information thank you