# Potassium Metabisulfite



## wine maker1 (Sep 23, 2007)

We started our new batch of wine for 2007. An 80/20 mix of Merlot and Cabernet Sauvignon. Yesterday we crushed the grapes added potassium metabisulfite and pectic enzyme. Today we tested for sugar and acid. The sugar was fine but the acid was low (0.4) we decided to add acid blend to increase the acid level. This is were it went BAD. One of our group who was in charge of adding acid blend mistakenly added about 1 pound of Potassium Metabisulfite. I have no idea what to do next. I finished the day by adding the correct amount of acid blend, yeast, yeast nutralizer and oakmur.Our batch is approximately 230 pounds of grapes (50 gallons of must). I read that too much pota meta will prevent fermentation. What do I do now? Can this batch be saved. Help I am desperate.


----------



## grapeman (Sep 23, 2007)

I am sorry that you had such a mishap. Is it really 230 pounds? That will yield approximately 15 gallons of pressed juice, so it should have had less than a teaspoon full of K-Meta. I'm afraid one pound will be way too much and the grapes are probably ruined. Sorry for your misfortune.


----------



## Wade E (Sep 23, 2007)

Wow, thats a lot of k-meta and dont think it stands a chance at that ratio. Stir the hell out of it and splash the heck out of it and maybe(but I dought it) you could get it going. The yeast you put in there is a goner and you will have to introduce a really strong yeast after all this but sorry to say I dont think it stands a chance in heck but ya never know.


----------



## wine maker1 (Sep 23, 2007)

I actually have two (2) FERMINATION vessels with 230 pounds of grape in each so each got about a half a pound of the pota meta. Any chance?


----------



## wine maker1 (Sep 23, 2007)

What do you mean by "splash" the heck out of it?


----------



## Wade E (Sep 23, 2007)

I mean to aerate it to expel the sulfate. Not sure exactly what 1/2 lb breaks down to in tsps. but if both of these are 25 gallon fermenters there should be 1 tsp in each.


----------



## masta (Sep 24, 2007)

I agree with appleman in that these grapes are ruined with that much K-meta added. 


A quick calculation of the numbers shows roughly 2300 ppm of Free SO2 which is impossible to correct unless you have lots more grapes to dilute them with.


appleman,


When using fresh crushed grapes what is the ratio you use for K-meta addition? The book I have says 2 grams per 5 gals of must for a 50 ppm Total SO2 rate which is close if I use my SO2 calculation.*Edited by: masta *


----------



## grapeman (Sep 24, 2007)

Winemaker, the only thing I can think of to do is let the grapes go through cold maceration and stir several times per day. That might get the sulfites down enough in a week to try to re-pitch the yeast again. You would need a lot of freeze bombs to keep temps down to 45 F for that long. 
You could try posting on WinePress.com. There area lot of more experienced large scale grape growers at that site. I don't normally recommend other sites, but they are likely to give you totally unbiased information on your situation. 


Good luck.


Masta, I don't do anything real scientific for calculating how much(I know I probably should, but...)K-Meta to add to the must. I simply do a rough calculation for how much juice I expect out of the grapes I have. For example - I figure roughly 15 punds grapes per gallon juice. so if I have 150 pounds of a variety, I would get about 10 gallons juice after pressing. If malo-lactic isn't going to be done, I use 1/4 tsp K-Meta per 5 gallons. In this example I would add 1/2 tsp k-Meta in the 10 gallons. With the crushed grapes it is just added to the must instead of pure juice. If the wine is going to be going through malo(ML), I will cut the rate in half.*Edited by: appleman *


----------



## pizzaerick (Sep 24, 2007)

I have a similar problem I was just coming on here to post. We had about 3 tablespoons in 7 gallons. 

I have done a lot of splashing, and I *think* I'm down to around 100ppm.

I'm trying to make a desert wine and so it's a double whammy with sugar at 35+ brix and the meta off the chart. 

What kinds of yeast deal better with high meta levels? I pitched Rudesheimer and it didn't take. I tried letting the juice air a bit, and did more splashing and pitched EP2 (Cote Des Blancs). I am not 100% sure wether it took or is dead as everything I have read says high sugar really slows the fermentation. I am getting a few bubbles on the surface after a day, but nothing like I am used to.

ideas?


----------



## rshosted (Sep 24, 2007)

This might help you to contend with that high brix, as for
the high sulphite level you will have to try and splash more if it doesn’t
work: 



Take out about ½ liter of must and mix it with ½ liter of
water to bring the brix down. Add a little yeast energizer, and then make a
starter of a strong yeast. Once it is going add it to the liter of mixed must
that you created. Let it ferment down for a day. As soon as it gets the brix
down to about &lt; 1.020, add another ½ liter of must from the original batch. Continue
like this adding ½ liter until you have 2 full liters and the wine comes down
to &lt; 1.020, then add a liter of wine at a time, until you have a gallon. It
should take about 4 days +-. You will probably want to keep the original large
must refrigerated during this time (but make sure you bring the must you add to
the wine up to room temperature prior to adding it to the must as it is already
weaker). Once you have a gallon, add a half gallon. When it gets up to two
gallons add a gallon, and so on until you have added all the must to the wine. 



Take good notes of where the brix/SG is at and if you find
at 2-3 gallons it stops you’ll want to make an executive decision if you want
to add more or start over, then blend the two. Also make sure you keep and eye
on your acid levels as this will and can affect a high sugar wine like this.
Worst case if you get it to work on some, you an make a port style wine and
fortify it later. 



Good luck, let us know how it goes. </span>


----------



## grapeman (Sep 24, 2007)

Pizzaerick, if you can get the sulfite levels down more, you might be able to get it going, but how did you come up with adding 3 tablespoons per 7 gallons- that's about 25 times the recommended amount! All those sulfites are preventing any kind of yeast activity- even at 100 ppm if really that low.
Here is a link to some icewine recommendations for yeast, etc.
http://www.scottlab.com/info-center/documents/ICEWINE.pdf


----------



## masta (Sep 24, 2007)

Please lets us know how you make out with this. A quick calculation of the numbers shows with an addition of 3 tablespoons to 7 gallon you added roughly 580 ppm of Free SO2 (assuming 50% becomes bound).Dilution might be your best option. 


Came across this info again yesterday as I was preparing my presentation for Winestock and if you get really desperate and are willing to risk it all then this info from Ben Rotter's site might help:



<H3>15.3. Hydrogen Peroxide </H3>
<H4>15.3.1. Theory </H4>Free SO<SUB>2</SUB> can be removed by adding hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) to wine. The use of H<SUB>2</SUB>O<SUB>2</SUB> is considered too severe by many. Nevertheless, it remains one of the only real options for removing excessively high levels of SO<SUB>2</SUB> from wine for the non-commercial winemaker.

The removal reaction is:

<CENTER>
<TABLE><T>
<T>
<TR>
<TD>SO<SUB>2</SUB></TD>
<TD>+ H<SUB>2</SUB>O<SUB>2</SUB></TD>
<TD>===&gt; </TD>
<TD>SO<SUB>4</SUB><SUP>--</SUP></TD>
<TD>+ 2H<SUP>+</SUP></TD></TR></T></T></TABLE></CENTER>
The molecular weight of SO<SUB>2</SUB> is 64.1 and that of H<SUB>2</SUB>O<SUB>2</SUB> is 34. Therefore, 0.5304 g (1/64.1*34) of H<SUB>2</SUB>O<SUB>2</SUB> is required to react with 1 g of SO<SUB>2</SUB>. 

The peroxide reacts with molecular SO<SUB>2</SUB>, changing the SO<SUB>2</SUB> equilibrium. Since this equilibrium is continually re-establishing, the H<SUB>2</SUB>O<SUB>2</SUB> should be added slowly. Additionally, since H<SUB>2</SUB>O<SUB>2</SUB> is such a powerful oxidiser, the amount added should be calculated carefully. Analytically testing the SO<SUB>2</SUB> content before and after H<SUB>2</SUB>O<SUB>2</SUB> addition is advised.

Solutions of H<SUB>2</SUB>O<SUB>2</SUB> commonly come as 3% solutions. If they are mass/mass solutions (this appears to be the typical case) they should contain about 30.3 mg/ml H<SUB>2</SUB>O<SUB>2</SUB>. If they are volume/volume solutions they should contain about 42.3 mg/ml H<SUB>2</SUB>O<SUB>2</SUB>. (See "Information on H<SUB>2</SUB>O<SUB>2</SUB> content" below for more details.) 


<H4>15.3.2. Example using H<SUB>2</SUB>O<SUB>2</SUB></H4>15 litres of wine has a free SO<SUB>2</SUB> level of 70 mg/l. It is desired to reduce this to 40 mg/l. The reduction of 30 mg/l (70-40) requires an H<SUB>2</SUB>O<SUB>2</SUB> addition of 16 mg/l (0.5304*30). Thus, the 15 litres requires an addition of 240 mg (15*16) of H<SUB>2</SUB>O<SUB>2</SUB>. Using a 3% mass/mass solution of H<SUB>2</SUB>O<SUB>2</SUB>, 7.9 ml (240/30.3) of the solution needs to be added to the 15 litres for the drop to 40 mg/l.



<H4>15.3.3. Information on H<SUB>2</SUB>O<SUB>2</SUB> content </H4>Pure (100%/weight) H<SUB>2</SUB>O<SUB>2</SUB> has a density of about 1.41 g/ml. 
Mass/mass solutions: 3 g H<SUB>2</SUB>O<SUB>2</SUB> / (97 g H2O + 3 g H<SUB>2</SUB>O<SUB>2</SUB>) means a volume of 97 ml + (3 g / 1.41 g/ml = 2.13 ml) = 99.1 ml. This contains 3 g per 99.1 ml which is 30.3 mg H<SUB>2</SUB>O<SUB>2</SUB>/ml of the 3% solution.
Volume/volume solutions: 3 ml H<SUB>2</SUB>O<SUB>2</SUB> / (97 ml H<SUB>2</SUB>O + 3 ml H<SUB>2</SUB>O<SUB>2</SUB>). 3 ml H<SUB>2</SUB>O<SUB>2</SUB> provides (3 ml * 1.41 g/ml =) 4.23 g H<SUB>2</SUB>O<SUB>2</SUB> per 100 ml solution, which is 42.3 mg H<SUB>2</SUB>O<SUB>2</SUB>/ml of the 3% solution.
*Edited by: masta *


----------



## Wade E (Sep 24, 2007)

Pizza, dont know if the Cotes Des Blank will take at that Dosage of meta but as many times as Ive used that yeast, it always seems to take 2-3 days to get going vs. sometimes a few hours for almost every other yeast but I like the end results with my fruit wines.


----------



## pizzaerick (Sep 24, 2007)

O.K.
First I didn't add the meta, but what we were going for was to hold the juice until it froze outside, remove the ice, and be left with concentrated juice to turn into an ice wine. We added a LOT of meta with the intent of keeping the juice for a long time. My friend has done this before.

I changed the plan by deciding to freeze the juice in my freezer and removing the ice to get the juice to 40+ brix.

So, that's the history.

Now, I have stirred, splashed, and allowed the juice to air over the last few days. I *think* my main bucket of juice is down to around 100. 

Thanks to the genius suggestion of diluting a liter of juice to start fermentation, I pulled out a liter. Using another suggestion I put it in the blender, and testing showed the SO2 down to 70 after a bit of whipping in the blender.

I then (on the liter) added 5ml of hydrogen peroxide. Now this is interesting. My SO2 came WAY down to 25, but the juice turned dark... from a boy scout khaki color to a beer bottle brown. I think I'm O.K. with 5 ml in 3 gallons, but I am not comfortable adding the amount of peroxide it would take to treat the entire 3 gallons.

So, evaporation and splashing have brought the level down. I'll get a liter started tonight, add a little more juice 2-morrow, and hope that over the next couple days the level falls a bit more. I wont know with anything but the "nose test" because I used my last tirettes test!

Anyway. I have nothing to loose following through with this. If it turns out a disaster, it will be a lesson learned for next year! I figure I got 40 or 50 more harvests to figure it out before I die!


----------



## dfwwino (Sep 24, 2007)

Unfortunately, some of us have a few less harvests left to figure it out.... 


Let us know how the wine tastes after the addition of hydrogen peroxide. I had read about that solution before, but--knock on wood--have never had to try it yet.*Edited by: dfwwino *


----------



## pizzaerick (Sep 30, 2007)

FINALLY! Got the dang thing fermenting! Probably will have off tastes from the 9 different times I tried to start it! One Rudesheimer pack, then 2 Rudesheimer packs, then Cotes de Blanc, then a second time, then 1117, then EP2 (Cotes de blanc from a different maker), 2 more times trying cotes de blanc, and FINALLY w15!

The batch is now bubbling away.

I know Cotes de blanc is a slow starter, but at the end even my starters were not going active after 24 hours +. I know the Rudesheimer was killed off by the so2, but I wonder if the CDB was not from a bad batch or something. BTW I got the yeast from 3 different suppliers, but all had a March 10 date on them.

THe only thing I can really say about the peroxide so far is that it DID lower the so2 levels, and it made the juice really dark, but a day later the juice lightened up again.


----------



## s.arkvinomaker (Nov 26, 2007)

The only thing that may effect those off flavors from the yeast will be time. You may have to this age longer than originally intended. Like maybe two years. Hopefully some creative finishing may help the rest.


----------

