Originally Posted by tellish33
Do you need to sorbate before bottling if you aren't going to sweeten? I was probably just going to bottle as is and add 7up or something.
If you have truly fermented it "dry", then the yeast has consumed all available sugars that have been broken down enough to be digestible. At this point, the yeast will mostly have gotten tired or overstressed from lack of nutrients and will flocculate out (i.e. sediment to the bottom) - what remains in solution will be dormant (essentially in hibernation). As long as you don't add new sugars or nutrients, that yeast should remain dormant. (It's worth pointing out that an increase in temperature can rouse the yeast and set it back to work on more complicated sugars still in the liquid.)
To be (relatively) sure of a "fully dry" or complete fermentation, the wine must stabilize at a specific gravity that remains constant over several days. Ideally, you should take a gravity reading at your set fermentation temperature, then again about a week later at 10*F or so higher (a gentle short temperature raise at the end of fermentation can help clear out unwanted phenolics/etc. (just read up on diacetyl rests!) and can boost the yeast to finish up, although unpleasant side effects can occur if the temp is raised too fast or too high). This will encourage the maximum amount of reasonable difference in gravity readings (remember to adjust your hydrometer reading for temp!). As long as the difference is measurable, your yeast is still working (it works slower as it gets more tired).
Once you are satisfied that you are done with fermentation, "cold crashing" (i.e. dropping the temp by 10-20*F, again....GENTLY) can help the remaining yeast flocculate out, giving you a clearer, cleaner-tasting product with less yeast in it - which will reduce chances of yeast reawakening in the bottle.
1 - Measure your SG. Raise temp slowly. Measure SG.
2a - If SG has changed, return to fermentation until it does not change.
2b - If SG is constant, drop temp slowly to below original fermentation temp.
3 - Transfer and bottle with comfort and confidence.
By the by, it's worth making sure your fermentation has completed even if backsweetening - otherwise, it is difficult to properly adjust your sweetening to taste, as the residual sweetness remaining will not have the same quality as sugars added later for backsweetening. Also, a completed fermentation does not need nearly as much sorbate, etc. to kill the yeast before backsweetening (less dead yeast in the liquid to effect flavors too). Finally, if you use any software to calculate your projected final gravity, be aware that they all assume that you're finishing the fermentation. Bottling any beer or wine before the fermentation is stable is a gamble for bottle-bombs.