View Full Version : Too Much Potassium Metabisulfite

07-06-2015, 12:11 PM
I was following a recipe for mango peach mead yesterday and when I added the potassium metabisulfite to the must (to kill wild yeast for 24 hrs before pitching yeast). I followed the label directions of adding 1 teaspoon per gallon. Afterward I read in a couple of different recipes that said to add in the neighborhood of about 1/8 tsp per gallon so of course I got worried and looked into it more. I checked the website info from the store where I bought it (Brewers Connection) and it says to add a tsp per gallon for sterilizing but only 1/8 tsp per gallon to kill wild yeast in must. So I guess the amount to add on the label is only for sterilizing. I wish the label stated that. So my question, did I screw up this batch (again) or can I continue to add the yeast today and proceed as planned? I've read the finished product can have a sulfur taste if you add too much as I did.

Thanks, Gene

07-06-2015, 06:00 PM
An expert will be along soon, but until then I'll help. :)

The good news is that you can oxygenate the heck out of this now before pitching the yeast and you should be fine. The potassium metabisulfate will bond to the oxygen and be rendered inert. Any left sitting in the must that had not bonded to oxygen will once you aerate it. I'd go over and beyond here. Do you have a tool that attached to your drill to help stir? If so, do that. Let it sit for a while then do it again.

If it were me, I'd do this several times and let it sit overnight. Then dose with the typical amount tomorrow (I use 1/4 tsp per 6 gal). Wait 24 hours more then pitch yeast.

07-06-2015, 06:09 PM
Roger that. I've been reading frantically about this situation and I found I'm not the only one to make this mistake. I don't have the aerating tool but I'll stop at the brew shop and get one on my way home tonight. I'm also planning on getting an SO2 kit and checking the level after stirring. Like you said too, I'll wait another day or two before pitching the yeast.

07-06-2015, 09:14 PM
I would add any more at all. I think it will take a few days before it will become ferment-able. In the mean time I would get a starter going. That way , when you do pitch you will have a better chance.

07-06-2015, 11:12 PM
Well I got the wine de-gasser that fits in a drill but they didn't have the so2 test kit so I passed on that. I'll try another shop tomorrow. I aerated the must pretty vigorously twice for 15 minutes each for a total of 30 minutes. I got a fair amount of bubbles each time so I think it helped. I'll let it sit overnight again and agitate some more tomorrow. If I get a test kit and it reads < about 300 ppm I think I'll be ok.

07-09-2015, 12:29 AM
Great news - I pitched the yeast yesterday and she was fermenting away when I got home from work this afternoon! Man, pheeeew, I was a bit worried there. So apparently (3) 15 minute sessions of aerating with the drill de-gasser did the trick. I seriously thought I was going to end up with a bucket of dead yeast. I was extremely relieved that I didn't ruin the batch. That can get expensive after a while. Thanks much for the suggestions everyone - very much appreciated.


07-11-2015, 10:12 AM
Glad it's off and running!

07-13-2015, 05:32 PM
AND won't have to worry about stray yeasts!