Over sulphited the must, pre-fermentation

[Jord]

So I feel like a total dipsh!t for not thinking but......

I took the time to juice 2.5 bushels of apples for a batch of cider (yes it took far too long) and wanted to add pectic enzyme to it so I figured I should add some sulphite to keep everything safe while the enzyme did its work. Without thinking I added around 2 teaspoons of K-metabisulphite along with the pectic enzyme. I have no idea why I dosed that amount but the damage is done.

My issue is that there's too much residual sulphite in the must to allow fermentation to start up. I've aerated the crap out of it on numerous occasions and there's still a slight sulphur odour and taste to it.

Is there any way to precipitate the sulphite out or do I just need to keep aerating it?

I've now odded three different packets of yeast over the past week in an attempt to get it going but have finally come to the realization that it's just not going to happen without some more work.

Any help would be appreciated.

Thanks.

 

[Medsen Fey]

Sulphite can be eliminated with Hydrogen Peroxide. However, to dose it properly, you need a test kit or titrets to measure the SO2.

Another alternative would be to make it a cyser and add honey which will bind a load of SO2, and use a yeast with high SO2 tolerance (Uvaferm 43 would be my choice).

How big is the batch ( so we can estimate the Total SO2)?

 

[Jord]

Thanks Medsen.

It's approximately 4 - 4.5 US gallons. I might have to do the cyser thing though I was looking forward to a low octane cider as I've got quite a bit of 12%+ beverages around here. Perhaps I could still keep it a bit on the lower side.

 

[Medsen Fey]

Okay, if we assume that KMeta is about 6.1 grams per tsp, you've got 400-450 ppm total SO2 in there (please double check my numbers). It would help to get an exact measurement - If there is a LHBS that has the appropriate tests available, I'd go get it now.

There is a wonderful little sulfite reduction calculator on Vinoenology. People who have used it find that the number they actually need may be much less than what the calculator produces (by 50%), so it is smart to go in increments and measure the results. If you assume that you want to reduce the SO2 by 200 ppm, you'd need to add 55 cc of 3% hydrogen peroxide.

I hope that helps.

Medsen

 

[Jord]

Ask and ye shall receive. Thanks again Medsen! I'll go have a look at the LHBS today at lunch.

 

[Jord]

Uh oh. I finished calling all of the LHBS's in my area and none, that's right none, of them sell sulfite test kits. Not that I want to do more damage but I think I'll move ahead with the hydrogen peroxide based on the numbers Medsen used. I'll start with 1/4 the recommended amount and go from there.

Now without having a test kit is there any way to know when the SO2 has been reduced enough so that I don't add too much? I guess worst case scenario would be to add the peroxide, let it normalize over several hours, pitch yeast and wait. Give it 24 hours and if there's no action add some more peroxide, rinse and repeat until something takes off......

Thoughts?

 

[Jord]

Okay so I found this website (http://www.weekendbrewer.com/wineproblemsremedies.htm#Excessive) that seems to have a plausible method for dealing with this issue without chemical additions. I think I'll give it a shot.

Basically aerate the poop out of it using my lees stirrer attached to the drill for 5+ minutes 4 times in 24 hours (or until the sulphur odour is gone) and then make a modified yeast starter and slowly bring the volume back up to the whole 4.5 gallons. I figure it's worth a shot at least before I start the blind adventure in my post above.