I’m still very new to this but I have a question about sugar and yeast.
What happens if you double the amount of yeast for an extract kit? Will you get a higher ABV % since there would be more active yeast to create more ethanol?
Also would adding high sugar ingredients, like honey, at some point in my boil create a higher ABV % since there would be more sugars to for the yeast to eat?
What happens if I did both to a batch?
Thanks Everyone
Higher ABV is generally a function of the amount and type of fermentables (i.e., sugars) in the wort. When the yeast have consumed all available fermentables in the wort, they cease to create alcohol.
Adding more sugar would create higher ABV assuming you pitch a proper amount of yeast
You’re onto something here. If you have a wort with more fermentables, you need to pitch more viable yeast…not only to ensure it attenuates fully, but to ensure you don’t get off flavors from stressed yeast.
Edit: I’m oversimplifying, but this is the general idea. There are other factors that affect the outcome, such as fermentation temperature.
Okay so my immediate question then is, can too much yeast be bad and can having too much leftover sugars be bad?
Pitching too much yeast can lead to a blah beer because the yeast produce byproducts during reproduction that add character to the beer and if there’s more than enough yeast at the beginning of fermentation there won’t be much reproduction. But over-pitching is far better than under-pitching which can lead to your second situation - leaving unfermented sugars in the beer is rarely a good thing and if you don’t pitch enough yeast, don’t aerate the wort (if using a liquid yeast), prematurely rack the beer off the yeast, or cause a rapid cooling of the beer that stops the yeast early (these are just a few of the cases that can lead to under-attenuation) you can end up with a sweet, cloying beer.
+1 to Shadetree’s response.
There are some good videos here where pros from White Labs and Wyeast talk about yeast: viewforum.php?f=38
There is also a demo showing how to make a yeast starter, so you can avoid under-pitiching which I believe is a much more common mistake than over-pitching.
Thanks guys, I appreciate the advice. I have two going now that I used safale for and they are both going good. I was just curious if there was a simple way to add sugars to increase the gravity. I think I’m just going to try adding honey or brown sugar to a test batch next time around.
[quote=“tkeefe66”]I think I’m just going to try adding honey or brown sugar to a test batch next time around.[/quote]I would just use regular table sugar, you won’t get any noticeable flavor from adding honey or brown sugar to the boil. Don’t go too crazy with it either, I usually use about 10% when I add sugar.
Dr. Clayton Cone of Lallemand and Neva Parker of White Labs have an opposite viewpoint. The same enzyme, acetyl co-A, is used for both yeast growth and ester production. If it’s doing one, it won’t do the other. So, if you pitch too much yeast, you won’t need cell growth and the enzyme will produce esters instead. And vice versa.
Dr. Clayton Cone of Lallemand and Neva Parker of White Labs have an opposite viewpoint. The same enzyme, acetyl co-A, is used for both yeast growth and ester production. If it’s doing one, it won’t do the other. So, if you pitch too much yeast, you won’t need cell growth and the enzyme will produce esters instead. And vice versa.[/quote]
Agreed. I finally encountered an over pitched pale ale and it had much more esters than expected - and that was with US-05 slurry. The beer is drinkable, but a bit clovey. Some love it, others avoid it.
Yup! A pound of table sugar adds 7 gravity points to a 5gal batch or about 1% ABV. It’s fully fermentable so adding too much will dry out the beer.
[quote=“Denny”]Dr. Clayton Cone of Lallemand and Neva Parker of White Labs have an opposite viewpoint. The same enzyme, acetyl co-A, is used for both yeast growth and ester production. If it’s doing one, it won’t do the other. So, if you pitch too much yeast, you won’t need cell growth and the enzyme will produce esters instead. And vice versa.[/quote]I’ll defer to the experts, but that goes against what I’ve read as “common” Belgian practices (deliberately under-pitching just a little to get more character) and my own experience with the occasional over-pitching (although I mostly make hoppy beers so the subtle flavors might be masked anyways). And of course, lab results don’t always translate to real world beers or cover all the possible wort compositions and yeasts.
In recent discussion on Brewsbros, a QC scientist from Sierra Nevada confirmed what Cone and Parker have said. There are some yeasts (some Belgians as you mentioned and weizen yeasts) that respond oppositely, but more yeast=more esters seems to be true of most strains.
[quote=“Denny”]In recent discussion on Brewsbros, a QC scientist from Sierra Nevada confirmed what Cone and Parker have said. There are some yeasts (some Belgians as you mentioned and weizen yeasts) that respond oppositely, but more yeast=more esters seems to be true of most strains.[/quote]That makes sense. And I assume the threshold for overpitching would depend on the yeast strain too - if you’re using something with little or no character then you might be able to get away with a lot more extra yeast than with something English and super-fruity.
Thanks everyone for the responses. I’ve come to this:
I need to know the math behind sugars added tp a wort & the math behind yeast eating sugar.
That way if I can calculate pre-brew; if add x amount of sugar with x type of yeast I can then know the needed ratio of yeast to sugar.
The whole point of this thread is to determine if I can take a recipe I enjoy and create higher ABV% versions. All without changing the flavor too much. I know by increasing sugars andyeast my flavors will change but I want to go about it in a way that alters the flavor the least while still increasing ABV%
Thanks!
[quote=“tkeefe66”] I know by increasing sugars andyeast my flavors will change but I want to go about it in a way that alters the flavor the least while still increasing ABV%[/quote]Add one lb of cane sugar either to the end of the boil or to the fermenter after primary fermentation has settled down and you’ll add ~1% ABV in a 5-gal batch. Should be no flavor impact, just ethanol, as a result.
I’m not an expert by any means, but I either heard or just assumed that at a certain ABV that yeast will no longer be able to be active and this will also depend on the type of yeast strain.
Is that completely made up or is there some truth behind that?
Yes, yeast has an upper limit for alcohol tolerance and it varies across the many strains, but as long as you stay under 10% the majority of standard yeasts will handle it no problem. If you’re going higher than that, just check the info on the yeast you want to use. I have a Belgian Imperial Stout on tap now, 13+% ABV, made with WY3787 (the Belgian yeasts are like the amps in “Spinal Tap” - they go to 11).
