Re: too much metab....

Sorry if my tone is a bit caustic, it just bothers me to see someone get

It's not so difficult to make a yeast starter (and it's good practice, whether making wine, beer, or bread). You put 1/2 cup of warm water (preferably around 95ºF) in a glass jar, sprinkle in the yeast, swish it around, wait a few minutes, add 1/2 cup of your (unfermented) grape juice (or even 1/2 cup of warm water and 1 Tbs. sugar), add a pinch of DAP (if you have some), cover it, and let it sit in a warm place until the mixture begins to bubble and foam. Then, you can "pitch" it, i.e. pour it onto your must. Takes less time to do than to describe. But this way, you know the yeast is good, and the colony is vigorous before being exposed to all that residual sulfite (which will remain even after aeration).

For 25 gallons, you will need about 5 packets of yeast, so multiple the quantities I have for the starter by 5. I.e. 2.5 cups of water, 2.5 cups of juice (or 2.5 cups of warm water and 5 Tbs. sugar), 5 pinches of DAP.

Nor is aerating the must that difficult. 25 gallons will take a bit of time to pour or siphon back and forth. You can accomplish the same thing by stirring it vigorously with a piece of clean and sterilized PVC pipe, broomstick, or humungous spoon (if you have one).

The yeast that was already added IS probably dead or at least in a coma (from all the meta). Replace it with new yeast and don't worry about it.

Try not to get discouraged. Everyone makes mistakes, although many can be avoided by obtaining information ahead of time. Your 25-gallons can be saved. To give up now would be a waste.

Please don't give up. It is fixable. Look at this as a learning experience, and go forward. I wouldn't throw out anything unless you're absolutely, positively, sure you don't like it, or it is spoiled. Hang in there, we've all been there. Darlene