Yeast nutrients: excess alcohol?

Winemaking Talk - Winemaking Forum

Help Support Winemaking Talk - Winemaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

BabaPerson

Junior
Joined
Jul 23, 2011
Messages
28
Reaction score
14
I just made a Winexpert Bergais wine kit. I substituted CR51 yeast for what was supplied, and used Goferm and Fermaid. I have a subjective impression that the resulting wine is "hot", higher in alcohol than I would like.

1. Is it possible that by using the Go-Ferm and Fermaid that it increases the yeast's viability in the presence of higher alcohol, and that as a result I end up with a wine of higher alcohol?

2. If so, would you recommend racking and adding metabisulfite to arrest the fermentation when the desired SG is reached?

I really want to experiment with different yeasts, but I prefer an alcohol profile no more than 13 or 13.5%.

Thank you.
 
1. The amount of alcohol is going to be set by the amount of sugar that you started with. It is not possible for the yeast to generate more alcohol without more sugar.

2. It is not really practicable for the home winemaker to arrest an active fermentation. In particular, k-meta won't do it.

I suspect that the wine just tastes young, and therefore slightly harsh, and you are mistaking that for high alcohol levels.
 
Hi BabaPerson. Two quick answers and then a brief essay:
1. No
2. Not recommended. Stopping fermentation in mid flight is a lot like trying to catch a bullet between your teeth. It can be done - but it's done more by illusionists than by naive wine makers.

I have never made a kit and I am unfamiliar with the ingredients provided in a kit but my guess would be that every kit is designed for the yeast to ferment the sugar completely. If that is the case , and if the kit makers provide you with all the fruit sugar that is to be fermented then the only problems you might find when substituting the strain of yeast from the one the manufacturer of the kit provides is a) the yeast you selected cannot (for whatever reason) thrive in the sugar concentration they are now being asked to go to work in; b) the character of the yeast is not compatible with the flavors and aromas the manufacturer has designed their kit to highlight; or c) the mouthfeel of the wine aimed for by the manufacturer of the kit is no longer possible. In short the maximum potential ABV of the kit wine is fixed and the only thing you could alter by changing the yeast is to leave more residual sugar unfermented than the kit maker planned. Your wine really cannot have more alcohol in it simply because you selected a different yeast. BUT if you fermented at a temperature dis-preferred by your yeast or if the yeast was stressed then you may have produced what are called congeners and congeners taste "hot". I have no idea what the maximum ABV of the wine you made is but CR51 , I think is spec'ed to ferment to about 13.5%. Personally, I would never ask a yeast to work close to its limits. Putting a high demand on a yeast can also stress the yeast...

All that said, I am certain that kit manufacturers design their kits so that there is an optimum balance between the ABV, the sweetness (and that might be brut dry) , the flavor and aroma, the mouthfeel, tannins and acidity. When you modify this balance you need to do so fully understanding what you are doing: how will reducing the ABV affect the perception of sweetness, the perception of acidity etc.. Of course, the real issue may be that the CR51 fermented your must bone dry and dry wine may not be something you enjoy especially when the wine is as green (young) as it must be if you are talking about adding K-sorbate and K-meta to halt the fermentation.
 
Thank you Sour Grapes and Bernard for your generous responses. That is interesting and persuasive, and you both agree. I hope that you're right about the batch not being too "hot". That's my batch for everyday drinking, and it would kind of screw with the intent if its tasting all alcohol.

FYI, I also emailed MoreFlavor, who sold me the yeast nutrients. Here's their response:

"Thank you for your inquiries. It is true that with proper nutrient additions your yeast and fermentation will be more robust and able to ferment a little stronger. Usually the wine yeasts attenuate a very high amount of your sugar so they will almost always try to eat all of the fermentable sugars in your batch. The easiest way to balance out or avoid the hot alcohol flavor is to add more tannin or ferment a little cooler next time around.

"It is possible to arrest a fermentation by racking and using metabisulfite (AD495), potassium sorbate (AD520), and by chilling your fermenter below 50 degree Fahrenheit if you can. Once you've done all of this and seen your yeast activity halt you are able to back-sweeten by adding extra fruit sugars with your desired flavors."

PS: I broke my hydrometer, so I have no hard data to go on. Just ordered a new one. :(
 
Last edited:

Latest posts

Back
Top