Proper Sanitization Dosage

[Linetec]

Good Morning All!

Just a quick question, I've been reading the threads and posts on this site for some time but this is my first time posting. 4 Years into homemade wine making and in those 4 years I've visited this site as my go to which leads me to my question. I'm trying to get the right dosage for potassium metabisulfite solution in a 32oz spray bottle. I've ready from using 1/4 teaspoon to using 1 tablespoon.

What I gathered, 2 teaspoons mixed with a gallon of water is a common dosage. 128 ounces in a gallon so if my math is right, 128 broken down in quarters is 32ounces.
2 teaspoons divided by 4 equals .5 teaspoons (1/2 teaspoon)

So would 1/2 teaspoon in 32 ounce spray bottle be sufficient enough to sanitize?

Appreciate any feedback!

 

[Eddie_G]

I can't remember what's in my spray bottle but the reference book I have been using says 3 tablespoons (56g) per liter (33.8 ounces). What's in my spray bottle probably isn't that strong but it's enough to knock your socks off and you have to rinse well afterwards. I think 1/2 teaspoon per 32 oz sounds a little light.

 

[winemaker81]

My sanitizing solution is 3 Tbsp K-meta and 1 Tbsp acid (citric is supposed to be best, although I use what I have the most of) in 1 US gallon (128 oz) water. No rinsing is required, nor is it recommended as tap water used to rinse will have organisms in it. Just drip off the excess.

Based upon this, use 2.25 tsp K-meta and 0.75 tsp acid in 1 US quart (32 oz).

2 tsp in 1 US gallon is a light dose. K-meta doesn't sanitize instantly -- I typically let equipment stand at least 10 minutes after rinsing. With a light dose the time is probably longer.

@Eddie_G, your mixture is 4 times stronger than mine, and mine will burn your lungs. I recommend using a lighter dosage, as SO2 is bad for the lungs.

I run a fan when working with K-meta solution, and when feasible open windows.

 

[Linetec]

I can't remember what's in my spray bottle but the reference book I have been using says 3 tablespoons (56g) per liter (33.8 ounces). What's in my spray bottle probably isn't that strong but it's enough to knock your socks off and you have to rinse well afterwards. I think 1/2 teaspoon per 32 oz sounds a little light.

My sanitizing solution is 3 Tbsp K-meta and 1 Tbsp acid (citric is supposed to be best, although I use what I have the most of) in 1 US gallon (128 oz) water. No rinsing is required, nor is it recommended as tap water used to rinse will have organisms in it. Just drip off the excess.

Based upon this, use 2.25 tsp K-meta and 0.75 tsp acid in 1 US quart (32 oz).

2 tsp in 1 US gallon is a light dose. K-meta doesn't sanitize instantly -- I typically let equipment stand at least 10 minutes after rinsing. With a light dose the time is probably longer.

@Eddie_G, your mixture is 4 times stronger than mine, and mine will burn your lungs. I recommend using a lighter dosage, as SO2 is bad for the lungs.

I run a fan when working with K-meta solution, and when feasible open windows.

So could I just use 2 1/4 tsp of K-meta then? I don't have acid at this time. What about using Star-San in a spray bottle? I've read that some have used that.

 

[winemaker81]

So could I just use 2 1/4 tsp of K-meta then? I don't have acid at this time. What about using Star-San in a spray bottle? I've read that some have used that.

For years I used only K-meta, no acid. Lowering the pH makes it more effective, but is not required. So yeah, go with 2-1/4 tsp.

Star San also works.

 

[Linetec]

@winemaker81 Thanks for the feedback. There is so much info out on the web and it's hard to get a grasp on things. Everybody has their own ways of doing things and what works best for them.

So given the new dosage, if I spray down lets say a mixing spoon, is there a certain amount of time I have to wait before I use it to mix another pail of juice? I currently in the primary stage of fermentation, making 3 Cab Sauv, 1 ruby Cab and 1 P.N. Lot going on....lol...

 

[Scooter68]

StarSan works great for me. I use it for all sanitizing purposes and of course it's a no rinse product as well. I invested in 1 quart and a couple of years ago and it's still good. (Stored down in a cool basement) If using Starsan you might find it stays clear better if you use distilled water or purified water. Our tap water makes a cloudy mix immediately and normally that's a sign of a old mix. Great for wiping counters etc just all around good food safe sanitizer that you don't have to rinse off. And wait time for Star San is less than a minute. I normally wipe, drain the excess and go ahead and use the item/container.
Remember that with many of these sanitizers some metals may be adversly affected so pay attention to any discoloration or oxidation of the surface

 

[Linetec]

StarSan works great for me. I use it for all sanitizing purposes and of course it's a no rinse product as well. I invested in 1 quart and a couple of years ago and it's still good. (Stored down in a cool basement) If using Starsan you might find it stays clear better if you use distilled water or purified water. Our tap water makes a cloudy mix immediately and normally that's a sign of a old mix. Great for wiping counters etc just all around good food safe sanitizer that you don't have to rinse off. And wait time for Star San is less than a minute. I normally wipe, drain the excess and go ahead and use the item/container.
Remember that with many of these sanitizers some metals may be adversly affected so pay attention to any discoloration or oxidation of the surface

@Scooter68 I live in an area where I have well water. I've invested in a pretty good water filtration system which includes a dedicated reverse osmosis system. I've read that using RO water is beneficial when used with K-Meta or Star San. What is your dosage rate with Star San? I know it's 1ounce to 5 gal but do you break it down for a spray bottle?

 

[winemaker81]

@Linetec, the internet is the greatest method of sharing knowledge ever invented! Simultaneously, it's also the best method of disseminating wrong information .....

I typically triple-check sources of information, although there's several dozen folks who post here regularly whose posts I trust. A forum with reliable people is probably the safest source of info available, especially as we cross-check each other. IME if there is a group consensus on this forum, the information is reliable. YouTube and individual sites? Not necessarily so -- YouTube has many clueless winemaking videos.

From what I've read, K-meta water doesn't sanitize, it's the vapor. I've read that 10 minutes is the magic number.

Honestly, I don't keep track. All my equipment is well cleaned before being put away after use, and I visually check as part of my startup process. I have a couple of small (~2 US gallon) food grade buckets in which I place equipment and splash with K-meta water. By the time I'm ready to touch the first wine, the equipment has sat for 5 to 20 minutes.

In between batches, I quick rinse and splash again. I admit that in some cases I have not sanitized between batches, just shaking off the equipment. If your wines are all good, it doesn't matter. However -- it's better to sanitize in between.

Star San is probably a better sanitizing choice, as it works faster. But it's more expensive and is formulated for larger batches. I find having K-meta water on hand is easier, and it contributes a bit more SO2 to the wines. It's a personal trade-off and both work.

 

[Linetec]

@Linetec, the internet is the greatest method of sharing knowledge ever invented! Simultaneously, it's also the best method of disseminating wrong information .....

I typically triple-check sources of information, although there's several dozen folks who post here regularly whose posts I trust. A forum with reliable people is probably the safest source of info available, especially as we cross-check each other. IME if there is a group consensus on this forum, the information is reliable. YouTube and individual sites? Not necessarily so -- YouTube has many clueless winemaking videos.

From what I've read, K-meta water doesn't sanitize, it's the vapor. I've read that 10 minutes is the magic number.

Honestly, I don't keep track. All my equipment is well cleaned before being put away after use, and I visually check as part of my startup process. I have a couple of small (~2 US gallon) food grade buckets in which I place equipment and splash with K-meta water. By the time I'm ready to touch the first wine, the equipment has sat for 5 to 20 minutes.

In between batches, I quick rinse and splash again. I admit that in some cases I have not sanitized between batches, just shaking off the equipment. If your wines are all good, it doesn't matter. However -- it's better to sanitize in between.

Star San is probably a better sanitizing choice, as it works faster. But it's more expensive and is formulated for larger batches. I find having K-meta water on hand is easier, and it contributes a bit more SO2 to the wines. It's a personal trade-off and both work.

@winemaker81 Appreciate the input. I completely agree with you on checking and double checking and triple checking...lol. I've found a handful of youtube posters who based on their video uploads seem to coincide with the wine making processes that I've read on here.

I can remember my very first batch of wine I made from a juice bail and all the things I did wrong...lol...but you live and you learn. Having a site like this is a valuable tool because it gives you the ability to reach out to a community of members who have a vast amount of knowledge in this.

Thanks again for all the input.

 

[balatonwine]

What I gathered, 2 teaspoons mixed with a gallon of water is a common dosage. 128 ounces in a gallon so if my math is right, 128 broken down in quarters is 32ounces.
2 teaspoons divided by 4 equals .5 teaspoons (1/2 teaspoon)

So would 1/2 teaspoon in 32 ounce spray bottle be sufficient enough to sanitize?

Appreciate any feedback!

The base 16 English measure is a pain. Better to simply use the base 10 metric system everywhere. Much easier. And since you are only trying to sanitize, not trying to sulfite a wine, a few approximations will make it even easier.

33.8 US oz = 1 liter
1 tsp kmeta = 5.9 grams
1 gram Kmeta = 0.57 SO2 by weight

So we can approximate as follows:
32 oz = 1 liter
1 tsp = 6 grams (or 5 grams (ish) if you want to make the math even easier)
2 grams Kmeta = 1 gram SO2

And for all above:
1000 grams water = 1 liter

From there the math is easy. Simply decide your percent solution desired. Using stoichiometry.

For a 1% solution of Kmeta (i.e. 10 g Kmeta / 1000 grams water which is also 1 liter) (and yes, the grams of Kmeta + water will not be exactly 1000 g total... but this is for simplicity to get a basic sanitizing rinse, not to be overly exact -- especially since a teaspoon is hardly very accurate either.....).

(10 g Kmeta / Liter)*(1 tsp Kmeta / 6 g Kmeta)= 1.6 tsp Kmeta / Liter

IMHO, a 1% Kmeta solution is minimum for sanitizing. And since 1 liter is aboutish 32 US fluid ounces, I would use about 1.5 tsps.

All above assuming neutral water pH.

 

[Linetec]

The base 16 English measure is a pain. Better to simply use the base 10 metric system everywhere. Much easier. And since you are only trying to sanitize, not trying to sulfite a wine, a few approximations will make it even easier.

33.8 US oz = 1 liter
1 tsp kmeta = 5.9 grams
1 gram Kmeta = 0.57 SO2 by weight

So we can approximate as follows:
32 oz = 1 liter
1 tsp = 6 grams (or 5 grams (ish) if you want to make the math even easier)
2 grams Kmeta = 1 gram SO2

And for all above:
1000 grams water = 1 liter

From there the math is easy. Simply decide your percent solution desired. Using stoichiometry.

For a 1% solution of Kmeta (i.e. 10 g Kmeta / 1000 grams water which is also 1 liter) (and yes, the grams of Kmeta + water will not be exactly 1000 g total... but this is for simplicity to get a basic sanitizing rinse, not to be overly exact -- especially since a teaspoon is hardly very accurate either.....).

(10 g Kmeta / Liter)*(1 tsp Kmeta / 6 g Kmeta)= 1.6 tsp Kmeta / Liter

IMHO, a 1% Kmeta solution is minimum for sanitizing. And since 1 liter is aboutish 32 US fluid ounces, I would use about 1.5 tsps.

All above assuming neutral water pH.

@balatonwine Thanks for the explanation and appreciate you breaking it down the way you did!

 

[Rembee]

This is a sanitizer recipe that I have been using for the past 10 years and I have not had any issues with it. I make a 1/2 gallon at a time and keep it capped in a half gallon growler. I will replace it every 4 months.
I also pour it into a spray bottle for easy sanitizing of equipment like my hydrometer, graduated cylinder, glassware and stirring utensils. I also keep this solution in my airlocks.

It makes a quart,
1 quart chlorine free water
1 tsp citric acid or tartaric acid or acid blend
1/2 tsp potassium metabisulfite

 

[winemaker81]

It makes a quart,
1 quart chlorine free water
1 tsp citric acid or tartaric acid or acid blend
1/2 tsp potassium metabisulfite

Interesting. A bit more acid and less than 1/4 the K-meta of my formula.

I lack evidence to indicate which formula is correct. Honestly? I'd prefer your formula is better, as mine rips my lungs out if I get too good a sniff.

 

[wineview]

So could I just use 2 1/4 tsp of K-meta then? I don't have acid at this time. What about using Star-San in a spray bottle? I've read that some have used that.

All this talk about sanitizing with K-meta makes little sense to me. As a former brewer, I alway used Star San and continue to use it in my wine making. It requires only one minute of contact and no rinsing needed. A lot easier than the K-meta route IMO.

 

[wineview]

@Scooter68 I live in an area where I have well water. I've invested in a pretty good water filtration system which includes a dedicated reverse osmosis system. I've read that using RO water is beneficial when used with K-Meta or Star San. What is your dosage rate with Star San? I know it's 1ounce to 5 gal but do you break it down for a spray bottle?

That’s about 1.2 tsp per gallon. I say per gallon because I use distilled water and if sealed with a cap, in the gallon jug or spray bottle, Star San is effective for 3-4 weeks. You want the solution to be clear. I’m shooting from the hip here but you can also check the ph and it should be below 3. Feel free to correct me if I’m wrong on that number.

 

[winemaker81]

All this talk about sanitizing with K-meta makes little sense to me. As a former brewer, I alway used Star San and continue to use it in my wine making. It requires only one minute of contact and no rinsing needed. A lot easier than the K-meta route IMO.

From Five Star Chemical's site:

Star San is an EPAs registered sanitizer and must be used immediately. We do not recommend using it if has been in solution longer than an hour.

I make up a gallon of K-meta water and it's good for months.

 

[Rembee]

Star San is an EPAs registered sanitizer and must be used immediately. We do not recommend using it if has been in solution longer than an hour.

I was just doing a search for this lol. I knew that I read it somewhere before.

 

[wineview]

From Five Star Chemical's site:

Star San is an EPAs registered sanitizer and must be used immediately. We do not recommend using it if has been in solution longer than an hour.

I make up a gallon of K-meta water and it's good for months.

This is interesting. I haven’t had an issue in 20 years.

 

[balatonwine]

All this talk about sanitizing with K-meta makes little sense to me. As a former brewer, I alway used Star San and continue to use it in my wine making. It requires only one minute of contact and no rinsing needed. A lot easier than the K-meta route IMO.

The "web" is international. And Star San is not available in Hungary where I live (as far as I know). So, for me alone, I see little sense in suggesting I use Star San.

And for those that have Star San available, some people may simply like doing things differently. I say tomatoe you say tomatow.....

Also, using Kmeta solutions have other uses such as long term solutions for wood barrel storage.

And so on.

Ergo, it is complicated. What works for one, may not work for another. And at any forum I like to think participants provide a diversity of expertise where each individual wine maker can select the advise they may think that will work best for them.

Hope this helps.