Adding more yeast = higher ABV?

[xplazma]

if 1lb = ~5% per gallon then 6lb = ~30%
RedStar dry yeast is rated for 16% - amazon ASIN: B008EDD46M
so my question is does more yeast mean higher ABV if so ~ how much more does it add

 

[Maylar]

Nope. No matter how much yeast you use it'll quit at 16%. That's an approximate number, not cast in stone.

 

[bigdawg86]

The yeast will also only ferment sugars that are available to it... some yeast MAY ferment more complex sugars and give better attenuation, but if the yeast runs out of food the beer is done regardless of how much you put in.

 

[bernardsmith]

But honey ain't grain and mead ain't beer and attenuation means diddly squat in wine and mead making. For all intents and purposes there are no complex sugars in wine making that wine yeasts cannot digest without any problem. so , for all intents and purposes yeasts in wine are all equally competent and all have attenuation rates of 100%.

 

[xplazma]

With 6lb of honey per gallon their is 184% the amount of suger for the yeast to eat at what it is rated for because it would cap out at 3.2 pounds max so sugar isn't a problem

 

[vevenson]

The yeast might not even start fermenting with such a large amount of sugar present, you might want to use sugar breaks. Some yeasts can go up to 22% ABV if you are really careful about your nutrients, temerature, etc. I don't think you're going to go higher than that without distilling it.

 

[dmtaylor]

Nope. No matter how much yeast you use it'll quit at 16%. That's an approximate number, not cast in stone.

This. ^^^^

 

[FatDragon]

For all intents and purposes there are no complex sugars in wine making that wine yeasts cannot digest without any problem. so , for all intents and purposes yeasts in wine are all equally competent and all have attenuation rates of 100%.

Not entirely wrong, but certain factors can stress out or kill the yeast, including ABV%. If the yeast is dead, it's not going to ferment out to 100% apparent attenuation.

 

[Maylar]

The yeast might not even start fermenting with such a large amount of sugar present, you might want to use sugar breaks. Some yeasts can go up to 22% ABV if you are really careful about your nutrients, temerature, etc. I don't think you're going to go higher than that without distilling it.

You bring up a good point. Sugar puts osmotic pressure on the yeast's cell walls, and above a certain point they go into osmotic shock. The ferment can either stall or as you said, never start at all. Even getting to the 16% point can be a challenge. You're best chance is to start with lower OG and add honey incrementally as the ferment progresses.

 

[MarshmallowBlue]

I agree. 6 lbs per gallon won't ferment.

And the original yeast you add will grow and multiply to numbers far beyond what you pitch in a packet, so it doesn't matter how much yeast you add really. It's only going to ferment either all the sugars, or up to a point where it stops itself by producing too much alcohol (the ABV limit of the yeast). Like others said, it can creep a bit above this number, but not astronomically.

 

[bernardsmith]

Not entirely wrong, but certain factors can stress out or kill the yeast, including ABV%. If the yeast is dead, it's not going to ferment out to 100% apparent attenuation.

But I don't know that yeast "die" because of intolerance to ABV. Dilute that wine and even a year after bottling the yeast will become reanimated and continue to ferment... But you can certainly stress yeast and yeast cells do die - but none of that speaks to the brewers' concept of attenuation. There is nothing inherent about honey that Saccaromyces cerevisiae cannot ferment the available sugars brut dry. There is something inherent in malt sugars that this same strain of yeast cannot manage and some varieties of this strain can handle better than others - hence "attenuation".

 

[xplazma]

so if it maxes out at 16% doesn't it just mean its going to give a really sweet taste
so if i have 6.5 gallon carboy with 50% honey (39lb = 6lb per gallon) and the other 50% is water,yeast,energizer and nutrition why wouldn't it work
i mean my goal is a really sweet mead i have already done a 4.125 lb per gallon but i want it sweeter just didn't know if the ABV would be higher which now i know it wont

 

[vevenson]

You bring up a good point. Sugar puts osmotic pressure on the yeast's cell walls, and above a certain point they go into osmotic shock. The ferment can either stall or as you said, never start at all. Even getting to the 16% point can be a challenge. You're best chance is to start with lower OG and add honey incrementally as the ferment progresses.

This^^^^^^

so if it maxes out at 16% doesn't it just mean its going to give a really sweet taste
so if i have 6.5 gallon carboy with 50% honey (39lb = 6lb per gallon) and the other 50% is water,yeast,energizer and nutrition why wouldn't it work
i mean my goal is a really sweet mead i have already done a 4.125 lb per gallon but i want it sweeter just didn't know if the ABV would be higher which now i know it wont

 

[FatDragon]

so if it maxes out at 16% doesn't it just mean its going to give a really sweet taste
so if i have 6.5 gallon carboy with 50% honey (39lb = 6lb per gallon) and the other 50% is water,yeast,energizer and nutrition why wouldn't it work
i mean my goal is a really sweet mead i have already done a 4.125 lb per gallon but i want it sweeter just didn't know if the ABV would be higher which now i know it wont

Aside from osmotic pressure inhibiting the yeast, you will probably find that 6 lb/gallon is too sweet, since you're probably at least tripling the unfermented sugar versus your last batch. Why not start at 4.25 lb/gallon (a bit higher OG and potentially sweeter than your last run) and then backsweeten to taste?

But I don't know that yeast "die" because of intolerance to ABV. Dilute that wine and even a year after bottling the yeast will become reanimated and continue to ferment... But you can certainly stress yeast and yeast cells do die - but none of that speaks to the brewers' concept of attenuation. There is nothing inherent about honey that Saccaromyces cerevisiae cannot ferment the available sugars brut dry. There is something inherent in malt sugars that this same strain of yeast cannot manage and some varieties of this strain can handle better than others - hence "attenuation".

Fair enough, I'm not sure if they "die" or just go dormant in excessive ABV.

As for the points about potential attenuation, they're well-received. I just think it's important to make sure that the OP understands that 100% attenuation only happens if the yeast are able to ferment to that level without being inhibited by other factors, such as ABV rising beyond their tolerance. In the context of this post, your statement about 100% attenuation might have been read as confirmation that their 6 lb/gallon must would ferment dry with a yeast strain that's rated to 16% ABV, which it's highly unlikely to do.

 

[bernardsmith]

Leave aside osmotic shock - The yeast won't but for the sake of argument we can.. Having something like 2 lbs of unfermented honey in every gallon will be so sickeningly sweet that you might find that you will have no tooth enamel after a glass of this. But you can try this experimentally. Two lbs of honey in a gallon will raise the gravity of the water to 1.070. Mix some sugar in a cup of water measuring the gravity until it is at 1.070. Taste it. That's how sweet it will be.

 

[Maylar]

so if it maxes out at 16% doesn't it just mean its going to give a really sweet taste
so if i have 6.5 gallon carboy with 50% honey (39lb = 6lb per gallon) and the other 50% is water,yeast,energizer and nutrition why wouldn't it work
i mean my goal is a really sweet mead i have already done a 4.125 lb per gallon but i want it sweeter just didn't know if the ABV would be higher which now i know it wont

It won't work because that's too much sugar for the yeast to handle. The ferment will never start. Even 4.125 lb per gallon is a lot, that's about 1.144 SG. I'm surprised you were able to ferment that.

 

[Ryue]

Saying it will never start is inaccurate. It is POSSIBLE it won't start, or it may stall. Depending on your protocal and recipie/yeast it could vary. I started a batch about 2 months ago with a SG of 1.158, added appropriate amounts of Fermaid-K/perG and it was rip-roaring in 1.5 hours and is currently sitting at 15% ABV.

Edit: I did see a lag/stall for about 2 weeks around the 30 day mark, but another week later after racking it has started fermenting slowly again. Now I am just impatiently waiting for it to be done.

 

[bernardsmith]

It won't work because that's too much sugar for the yeast to handle. The ferment will never start. Even 4.125 lb per gallon is a lot, that's about 1.144 SG. I'm surprised you were able to ferment that.

I wonder if it might start if the honey and water is poorly mixed so that there might be strata with lower concentrations of sugar and so less osmotic shock and so as the yeast work through those layers and the CO2 agitates the solution (it's neither must nor mead) the honey is slowly mixed but the concentration of sugars impacts less on the cell walls because now there is less sugar (but more alcohol). There is a Polish mead which I believe is something like 2 parts honey to 1 part water - (No , that's not a typo -Poltorak, I think it's called) and the shock should prevent fermentation but apparently it doesn't...

 

[Maylar]

Saying it will never start is inaccurate. It is POSSIBLE it won't start, or it may stall. Depending on your protocal and recipie/yeast it could vary. I started a batch about 2 months ago with a SG of 1.158, added appropriate amounts of Fermaid-K/perG and it was rip-roaring in 1.5 hours and is currently sitting at 15% ABV.

Edit: I did see a lag/stall for about 2 weeks around the 30 day mark, but another week later after racking it has started fermenting slowly again. Now I am just impatiently waiting for it to be done.

But 1.158 isn't 1.210, which is where 6 lb/gal would get you. There was a fellow here last year who tried to get a 1.170 mead going, and even EC-1118 failed to start.

 

[mwilcox]

1/2 honey is basically Dwojniak. And yes, you can do that, and some even do it with all the honey up front. (I don't think the same could be said for Poltorak, which I don't know how to do without fortifying.) But you've got to get yeast slowly used to it to have even a chance of success, and there will be big variability by strain. This will take multiple days in my experience. Step feeding an initial lower gravity will be much easier for most, with as little extra honey added at the end as necessary - otherwise you're seriously diluting the ABV with added honey volume.

remember that alcohol tolerance can vary upwards above published limits, but can also be significantly lower under less than ideal conditions. High osmotic pressure is way less than ideal. Example: my ice cider with SG just north of 1.160 stops at around 1.075, or below 12%. It would normally ferment to at least 15% under less harsh conditions. If I start closer to 1.185, it'll stop around 9.5%.