SG question

[rhenson]

I understand the process of taking SG readings and it's use in determining if fermentation has completed and in calculating ABV, but have a question on it's use in regards to managing fermentation.

I'm doing kits now - learning, but hope to move to real grapes some time in the near future...but I digress, I think the question applies in either case.

My instructions read something like, let primary fermentation go until the SG is at least at some value...and then rack and rest until it is at or below another value (I'm not going to quote them, because I'll get it wrong). My question is, do you really need to be managing a daily SG check and stopping primary/secondary fermentation at a specific point so that you don't go to far?

Or, if one were lazy and sort of just waited a bit too long on primary to where when transferring to secondary the wine had really completed already - maybe already to .990 even, or if I let it set in secondary too long - will this cause issues? I'm thinking there is something important to controlling specific points in the fermentation, but can't find detail on it...so maybe it's not a problem and I can continue with my lazy ways...

Thanks for any clarification!

 

[banannabiker]

I am still fairly new to wine making-but here is my experience. The primary bucket serves several purposes (gas release, easy stirring, easy access to the fruit so you can kneed it as needed, and to allow a little oxygen in for the yeast at the early stages). When the fermentation slows, you have the danger of allowing too much surface area exposed to the oxygen-which is not really needed at this point. Your fruit has given up most of what it has to give by this point and needs to be removed, and your gas and foam outputs have dropped to minimal amounts. This should all happen at about the same time your sg reaches the place your kit is telling you to move to secondary. In secondary you have a limited surface area exposed to oxygen, but it still provides an outlet for the reduced levels of gas and foam produced. Moving the wine to secondary too late will expose your wine to too much oxygen because of the diminishing gas blanket coming from fermentation. Moving the wine too soon will probably result in an occasional mess as your fermentation decides to kick into gear for one last hurah and overflows the narrow neck of the jug. That being said-I don't think a day or two one way or the other is going to be a big deal. The guidelines given are meant to keep us in the ballpark, not to be calculated to the third decimal point.

 

[djrockinsteve]

Usually you remove fruit somewhere around 1.030-1.040 By this time all the sugar is out of the fruit and can be taken out and disposed of or some of us use it to make a blush or secondary wine.

Wine making can be very forgiving with many things. I know that by day 5 I can expect my gravity to be near 1.000 Here I will add 1 teaspoon of super ferment and stir very well then immediately snap on a lid with an airlock. In 2-3 days it will be bone dry (below .990) and I can rack to clear.

I occasionally will check gravity day 3 just to see how things are going. For those new you should check daily just to familiarize themselves with the process of wine making. Some musts take longer to ferment.

I stir a few times every day thru snapping on a lid. This adds O2, moves living and dead yeast along with nutrients around. It also releases CO2 so I don't have a volcano later and it makes it easier for yeast to breathe.