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m_lapaglia

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In relation to yeast, what does attenuation mean? How can I use this information to make better wines and ciders? I used some K1V-1116 with a OG of 1.056 and current SG of 1.002. Using the formula to calculate attenuation.
[(OG-FG)/(OG-1)] x 100 I plugged in the actual numbers. ((1.056-1.002)/(1.056-1))*100 = 96.42% attenuation.

1116 has an attenuation of 70%-80%. This is where I am still confused. I currently have 96% and its not done yet. Shouldn't it have stopped at about 80%? Or is it that I didn't have an high enough FG for attenuation to be an issue?
 

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Rocco
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I have not heard of attenuation so I did a quick google search as I was curious. Here is the definition I found:

Attenuation: Attenuation is the percentage of sugars that the yeast consume during fermentation. If the fermentation went to 1.000 gravity, that would be 100% attenuation. Understanding the different attenuation ranges of each strain will help determine the terminal gravity of the beer.

Further searches provided attenuation targets for strains of yeast used with champagne and mead making. Some yeast for white wine making also made mention of attenuation. For wine making you really need to be concerned with the alcohol tolerance of the yeast. If you are making wine with a target of 16% alc and the yeast strain has a tolerance of 14% then the yeast may stop consuming sugar once the alcohol obtains 14% and you would end of with a sweet wine.

Here is a link for hard cider. I don't know if you'll find information here about making a better cider.

https://www.leeners.com/hardcider.html
 

m_lapaglia

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I read that one also. My problem is I don't understand the relationship between alcohol tolerance and attenuation. As an example, K1V-1116 has an stated attenuation of 70%-80%. I currently have 96% attenuation on a Apfelwein batch and its not done fermenting yet. Shouldn't it have stopped at about 80%? Or is it that I didn't have an high enough FG for attenuation to be an issue? The SG was 1.056 and its currently at 1.002. If it had stopped at 80% attenuation then it should have stopped at about 1.011. Either I'm really confused or I have a major misunderstanding on how its supposed to work and why I should be concerned.

For the math people here are the numbers. Using this formula to calculate attenuation.
[(OG-FG)/(OG-1)] x 100 = attenuation

I plugged in the actual numbers and got.
((1.056-1.002)/(1.056-1))*100 = 96.42% attenuation.
 

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Rocco
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Are you making mead or cider? Because if you are saying your starting SG was 1.056 you would only end up with around 7.5% alcohol, not enough for wine.

I don't think I can help you with the attenuation as I don't quite understand the relationship either.

Edit to post: The only further research I can come up with is that unless you are making a dessert style wine or a sweet wine then 100% attenuation is desired which means all the sugar has been consumed. Attenuation would then seem to have something to do with the residual sugar remaining. For example 80% attenuation would equal 20% residual sugar (100% - 80%). So if you are starting with a really high SG multiply that by the attenuation amount to get the ending SG. If the ending SG is above the alcohol tolerance of the yeast then you could end up with a stuck fermenation. I only work with the brix scale so here is an example for a dessert style wine.

Starting Brix 33, attenuation of 80% would mean that I would end my fermentation at 6.6 (33 x .20). 33 brix - 6.6 brix = 26.4 x .55 = 14.52. .55 is the factor to multiple the difference between the starting and ending brix to determine potential alcohol. 14.52% is the potential alcohol so if I am using a yeast with a 12% alcohol tolerance it won't be strong enough to finish the job since my target is 14.52%. I am only speculating that this is how the relationship of attenuation to yeast tolerance would work.
 
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m_lapaglia

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At the moment in the primary is a cider. I too speculate that this is the relationship. I am hoping that someone here has the answers so we can get to the bottom of this and not need to speculate. Thanks for all you help so far.
 

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