making K-Meta sanitizer

[winemaker81]

I've been researching this topic and discovered that there is no consistent answer regarding how to make a potassium (or sodium) metabisulfite sanitizing solution. This includes searching this forum, which consumed a fair amount of time. Identifying the right keywords is harder than you might think.

I was originally taught to dissolve 2 Tbsp Na-Meta in 1 US gallon of water -- in that time period NA-meta was used as K-Meta cost 3 or 4 times as much. Later we switched to using NA-Meta for sanitizing and K-Meta in the wine. These days I use K-Meta for everything.

Recipes for sanitizing solution range from 2 tsp to 3 Tbsp K-meta in 1 US gallon. Some add acid (citric, tartaric, or blend) and some don't, although nearly every recipe I found that includes acid calls for 1 Tbsp.

What recipes does everyone use?


EDIT:
For those not familiar with the abbreviations:

NA-Meta = Sodium Metabisulfite
K-Meta = Potassium Metabisulfite.

NA and K are the atomic abbreviations for sodium and potassium, respectively.

BTW, "metabisulfite" and "metabisulphite" are both accepted spellings.

EDIT 2:
Indicated US gallons to avoid confusion.

 

[kmk]

Looking forward to answers to this question, since the more I read the more different amounts are suggested. For years I added one Campden tablet (550mg active Na metabisulphite) per gallon during initial set-up. Often times I would add a tiny amount once or twice more during the process.
Recently began using 1.2g/gallon of K metabisulphite which is a bit difficult to measure since I typically make less than five gallons of wine.
My references are: Successful Wine Making at Home, Winemaker's recipe handbook, From Vines to Wines, and Home Winemaking step by step.

 

[winemaker81]

@kmk, we're talking different things. My post regards sanitizing solution, e.g., a strong sulfite sanitizing solution to rinse hardware with.

Your post appears to regard adding K-meta to directly to wine.

The most common practice is to add 1 crushed Campden tablet per gallon initially, and at each racking. Campden is preferred for batches less than 5 gallons as the amount of K-meta added is small and, as you said, hard to measure. BITD Campden was NA-Meta, but I've recently been informed that a K-Meta version is sold.

The common practice for powdered K-Meta is 1/4 tsp / 1.2 g for each 5 gallons of wine.

 

[kmk]

Oh, yea, sorry, ADD on the computer. Let me try again.
I use(d) 1 Step (percarbonates) for years. Couple of years ago, I started using bottom-shelf vodka.
I also have some 1.6% active iodine (Io-Star sanitizer) which I haven't used yet.
Oh my, I still haven't addressed your request. I'm going to stop now.
Sorry.

 

[wpt-me]

I have been using 3 tbs k-meta and 1 tbs citric for my mix.

Bill

 

[Johnd]

I use 3 tablespoons of K-Meta and 1 tablespoon Citric Acid in one gallon of water for my solution. Citric acid doesn't cloud up like Tartaric will, and drops the pH down very nicely. I keep my solution in a one gallon glass jug with a nice, tight cap on it, it lasts for months that way.

 

[winemanden]

@kmk, we're talking different things. My post regards sanitizing solution, e.g., a strong sulfite sanitizing solution to rinse hardware with.

Your post appears to regard adding K-meta to directly to wine.

The most common practice is to add 1 crushed Campden tablet per gallon initially, and at each racking. Campden is preferred for batches less than 5 gallons as the amount of K-meta added is small and, as you said, hard to measure. BITD Campden was NA-Meta, but I've recently been informed that a K-Meta version is sold.

The common practice for powdered K-Meta is 1/4 tsp / 1.2 g for each 5 gallons of wine.

What makes it difficult and sometimes confusing, is that us folks in the UK have to remember that US and UK gallons are different. I've never noticed a salty taste myself, although I had a German friend who always added a pinch of salt to her drinks. She said it brought out the taste. As they say in Yorkshire 'There's nowt so queer as folks'.

 

[winemaker81]

Oh my, I still haven't addressed your request. I'm going to stop now.

This is the internet. Conversations going slant-wise is normal.

This thread will probably branch into cleaning solutions at some point, so you just jumped the gun.

 

[winemaker81]

I use 3 tablespoons of K-Meta and 1 tablespoon Citric Acid in one gallon of water for my solution.

I purchased an extra bag of acid blend by mistake last year, so I have 2 full 6 oz bags. Are there drawbacks to using acid blend, or is it a case that citric is just better?

 

[Johnd]

I purchased an extra bag of acid blend by mistake last year, so I have 2 full 6 oz bags. Are there drawbacks to using acid blend, or is it a case that citric is just better?

I've never used the blend, but the Tartaric when used alone will cloud up. Try the blend out, it may work even though it has tartaric in it.....

 

[winemaker81]

What makes it difficult and sometimes confusing, is that us folks in the UK have to remember that US and UK gallons are different.

I have world-wide net pals in other (non-winemaking) venues, so I am mostly in the habit of specifying correct units, e.g., USD for money.

1 imperial (UK) gallon is 153.7 US ounces, roughly 1.2 US gallons. Anything measured for US gallon needs 20% more, which for 3 Tbsp K-meta means to add another half Tbsp (roughly, but close enough for this situation).

This assumes that US and UK tablespoons are the same (ounces are not). If they are not the same, my brain is hurting too much at this point to research and/or translate!

 

[winemaker81]

I've never used the blend, but the Tartaric when used alone will cloud up. Try the blend out, it may work even though it has tartaric in it.....

The rule of thumb I was taught was for K-meta waters is "if it's clear and is stinks, it's still good". I can see where tartaric messes with that rule.

I added 1 Tbsp acid blend to a freshly made gallon of meta water -- after shaking a bit it's not fully dissolved; hard to tell if it's cloudy or not. I'll shake it periodically over the next few days.

Normally I use warm (above body temp) water when making meta water -- I put the meta in the jug, half fill it, shake well, then continue filling. That dissolves the K-meta. The current temp is about 72 F, 30 degrees lower than my normal mixing temp. I'll report back on what it looks like.

 

[cmason1957]

I use 2 Tbsp of K-Meta and 1 Tbsp of either Tartaric, Citric, or Acid Blend, depending on which one I happen to pick up. Back several years ago, I bought a full pound (or maybe 5 Pound) container of Acid Blend by mistake, so I use it up. I have never noticed a clouding problem with any of the ones I mixed up, but maybe I'm not looking close enough, if I take the lid off my gallon jug and take a small whiff and go wooo, that's strong, I use it.

 

[mainshipfred]

The percentages of acids in the blends vary from one manufacturer to another. LD Carlson is 10% tartaric, 40% citric and 50% malic. Cellar Science is 1/3 equal portions and I'm sure there are others. I use both 2:1 and 3:1 tbsp but read once the pH should be 2. Never measures either of the solutions though.

 

[wineview]

All this blending and measuring can be avoided by using Star San. I’ve used it as a brewer for 17 years and now wine making for three. It has never failed me. One liquid ounce per five gallons. You can easily reduce the amount for gallon batches using a tsp or fractions there of.

 

[Cellar Vader]

I've been using the 2:1 "tsp" recipe for my sanitizing spray. However, I have never tested the pH. I see some folks using the 2:1 "tbsp" recipe. Now I wonder if my pH has been low enough to be the most effective.
On the note of testing pH, I once read that if the solution's pH is too low, it could ruin your pH meter. Can anyone confirm this?

 

[Rice_Guy]

* my standard sanitizer is 1.5 gram citric, 21.5 grams metabisulphite mixed into 3 pints of tap water and stored in a glass growler With a cork. From memory this should be someplace in Pembachi’s book.
* you could use acid blend, citric acid has three ions that are driven off so it is efficient as well as readily available/safe, phosphoric acid would work better, the key is to have a pH low enough that a high percent of the meta is pushed to ionize into SO2
* from a stability point of view mixing with distilled would work better, ,,, in the QA lab days running dissolved oxygen there was enough organic in tap water to give a DO reading.

 

[user 36973]

I think this is one of those "ask 100 people, get 100 answers" type of questions. The key factors are (1) low pH (<3) to ensure a high portion of the sulfites are in the SO2- ionic form which does the sanitizing, and (2) sufficient sulfite concentration to be effective (>1500ppm)

I've posted this link to a cleaning and sanitizing guide by Presqu'isle before. They suggest 2tsp metabilisulfites and 1tbsp citric per gallon. I personally double these quantities for my sanitizer because I keep it in a wand sprayer for a couple weeks. However, this solution will chew through plastics and even trash the "acid grade" plastics after a year.
http://www.piwine.com/media/home-wine-making-basics/Cleaning-and-Sanitizing.pdf

solution's pH is too low, it could ruin your pH meter.

Your pH probe should be able to handle even a pH of 0 with no problems. However, proper care, cleaning and storage of your probe will allow it to last longer. I always rinse my probe off with a dilute NaOH cleaner, rinse with distilled water, rinse with the sanitizing solution above, rinse again with distilled water and store in pH electrode solution until the next use.

 

[kmk]

I've been using the 2:1 "tsp" recipe for my sanitizing spray. However, I have never tested the pH. I see some folks using the 2:1 "tbsp" recipe. Now I wonder if my pH has been low enough to be the most effective.
On the note of testing pH, I once read that if the solution's pH is too low, it could ruin your pH meter. Can anyone confirm this?

I used to work in a laboratory. If you're using a glass probe it should not be adversely affected by low (or high) pH values.

 

[winemaker81]

All this blending and measuring can be avoided by using Star San.

Is there honestly a difference? You put 1 oz Star San in 5 gallons. I put 3 Tbsp K-Meta in a gallon. Someone else puts 2 Tbsp K-meta and 1 Tbsp citric acid in a gallon.

We are all using measurements we've been told to use, and accepting that solution works.

This yet another wine making situation where there are numerous correct answers. Some answers are possibly "more right" than others, but there is no overwhelming "this is the right answer".