Originally Posted by Puffin
To answer one of the above questions, yes I pre-boil the water used for top off in the fermenter. I boil it to make sure there's no bacteria in it.
An update to my first use of campden tablet: I pitched yesterday around 3:30pm. Usually I've got pretty good bubble activity about 8-12 hours after pitching in every other batch I've done. This time, not so much. Only difference this time is using 1/4 tablet in my 3 gallons of wort, 1/4 tablet in my 3 gallons of top off. I also use my top-off water to rehydrate the yeast, BTW.
I understand my campden dosage is slightly higher than necessary (for the 1 tablet per 20 gallon rule) but I had read other posts about people using 1/2 to whole tablets per 5 gallons.
I'm guessing my slow start of fermentation is due to the use of these campdens. Only other variable that's new with this batch is use of a whirfloc tablet in the last 15 minutes of boil.
I do have a "weak" bubble activity now at the 24+ hour mark, but this morning when I got up and checked it, the water in the airlock indicated a loss of pressure in the fermenter! (from the cool down overnight). I've never had that happen before!
Anyone else notice a slower apparent reproduction rate of yeast after pitching as this??
Well, campden is potassium metabisulfite, which is an antimicrobial. I still say it's silly to both boil and add campden, because it's redundant. Campden kills wild yeast, bacteria, fungi, etc. It also acts as an antioxidant, and it interacts with chlorine to make it dissipate. That's why winemakers use it and love it. It kills critters in the must, so you can pitch your chosen yeast in a sanitized must. Winemakers wait 24 hours after adding campden before pitching the yeast, but it's a bigger dosage than you used.
But, in this case, you went over the dosage recommended. Normally you add 1/2 campden tablet to 10 gallons of brewing water, stir well, and let it sit out to dissipate. I'm not sure what boiling the sulfites will do, but it probably didn't all dissipate.
It sounds like you've pitched too warm, let it cool, added way too much sulfite, added sulfites to the rehydrating water for the yeast (OUCH!), etc. So, I'd say that you've stressed your yeast for sure. The good news is that yeast is pretty resilient and if it continues to ferment for you, you should be all set. I'm not sure what kind of off-flavors, if any, those factors will all produce, but it might be perfectly fine in the end.