Wine for science

[owenab]

Hello! I'm doing winemaking for science research purposes so I really want to make sure I'm getting the process right, our wine has finished primary fermentation and been racked off most of the sediment, but I'd like to do a secondary and im not quite sure where to go. I plan to add fruit in for secondary but how do I know when secondary is done? Should there still be some yeast or should I add a stabilizer and then the fruit? Does it count as secondary fermentation if the yeast is technically dead due to the stabilizer? I'm mostly jsut confused on the exact order i should be doing things.

 

[hungupdown]

Good luck with your project.
If you have a hydrometer, reaching the target SG (specific gravity) for dry / medium / sweet wine, is the best guide.

Not sure why you'd want to delay fruit, until secondary fermentation. But if you are, and the fruit has fermentable sugars, then you'd want to keep a bit of the sediment, and not add stabilizer (until secondary ferment has finished).

Once yeast is dead, any additions would mostly be for flavouring or sweetening, rather than fermentation.

Though, after stabilizers are added, there can still be enzymes remaining (previously produced by the yeast), which would convert some of any extra sugar added, to ethanol (and produce CO2).

I'll often let the yeast, ferment all the grape sugars, before stopping (by adding sorbate stabiliser). Resulting SG, is often around 0.990. Then sweeten to style. This could maybe be done with fruit, but I'd boil the fruit first if using this way.

NB degass wine, to remove sharp taste.

 

[waynetempro]

Maybe if you tell us more about the ingredients in the wine that you have done so far and what you want it to be like when it’s done.

 

[fluketamer]

hi

i make beer for scientific research so i understand where you are coming from .
i am researching how it tastes . it has been a very long journey. i have discovered that it tastes good. but i am still not done with my analysis.
i feel theres still more to explore.

good luck and welcome to homebrewtalk.

 

[bernardsmith]

Hi owenab - and welcome. Just very curious about your "science project"? What exactly are you hoping to look for or measure? How "scientific" is your project? In other words, what variables are involved and what are you controlling to determine the effects of changes to the variables? Also, how much wine making have you done before, so that you have a good handle on the processes and outcomes that seasoned wine makers may already understand?

 

[lumpher]

This could maybe be done with fruit, but I'd boil the fruit first if using this way.

I NEVER boil fruit when making wine. To sanitize it I let it sit in Campden for a day or so.

As pointed out, though, the main question is why do you intend to add fruit in Secondary? Is it for added flavor, to back-sweeten, or added fermentation? For added flavor ok, for back-sweetening I stabilize it then use sugar, and for added fermentation add it in primary.

 

[fluketamer]

yes i was also wondering what sort of experimentation you are doing since a secondary and fruit is involved. i would think that alone is alot of variables.,

when my kid was in second grade he did a sciecne project where he varied the amount of sugar in a yeast solution to see how much the yeast farted.

the end result was more sugar equaled more gas. up to a point. (no surprise)

what are you looking for and what are you trying to find out?

 

[Erik the Awful]

I also do not like boiling fruit. In my experience, it releases more tannins and can make the wine cloudy and bitter. I prefer to simmer the fruit for an hour or so. The milder heat still kills bacteria and helps release the sugars.