Originally Posted by Sammyk
How much campden for 30 pounds of frozen muscadines? I did not crush them before freezing. They are now thawing....
It has to do with the "free" sulfites your campden addition provides. There is, technically, a measurement behind it. (heavy on the "technically") But for your purposes, it is a matter of the ratio of sulfites to volume. Just go by the recommended dose on the campden bottle.
If you initially add sulfites just to the crushed grapes & berries and do not add all the water, the percentage sulfites will be higher and work better against undesirable organisms and wild yeasts present at that time. This would be adding the sulfite amount that you expect to use for your eventual *total* volume (with water and all).
Then after you add your water, you will have diluted the sulfite to its intended "regular" level.
Even though you've added it once, you may eventually have to re-figure and re-add more sulfite. This addition would further protect your wine and continues to prevent infection and oxidization that might take hold from future rackings and also in the bottle.
In any case, those further sulfite additions are generally best done after fermentation is completed.
edit: I see now that you already added the water. Not a problem but make sure your sulfites are appropriate for the total volume.