I put my wine in secondary at 1.025 and in 1 day it was down the 1.002. Why so fast? Did I do something wrong? Do I just let fermentation play out or do I stop it?
Speed of fermentation usually depends on:
- the amount of yeast cells (and nutrients)
- the temperature of fermentation (the higher the faster)
To slow down fermentation:
- Drop the temperature using Ice Packs or other cooling devices
- Additives like SO2 could slow yeast as well
At 1.002 you are almost done, I would let it finish.
Exciting the wine can also give a burst of fermentation. Since your wine was actively fermenting, and you moved it into a secondary you more than likely degassed it just a bit, raised the pH a touch as a result and the yeast liked it better.
That’s all anecdotal, but it’s likely.