Ale Yeast Tolerance to Sulfites

[ejcrist]

I read on the North Corner Brewer website (http://www.northcornerbrewing.com/page/cider.aspx) that ale and lager yeasts are intolerant of sulfites above about 15ppm. Is that true? I have two batches going and two more I'll be launching this weekend and all are using ale yeasts. I'm planning to lightly carbonate before bottling and just using the yeast that remain after racking so this is relevant. I guess if you were making a still cider or adding a wine yeast with priming sugar it wouldn't matter but in my case it will.

 

[lumpher]

it works. been there, done it many times.

 

[ejcrist]

Understood. This brings up another question though, and I don't have the numbers in front of me but I'll give you the gist of it. Ale yeasts have attenuation rates of anywhere between about 60%-80%, and I think S-04 for example max attenuation is 75%. That being the case, if you fermented apple juice/must with an OG of 1.050, it would stop somewhere around 1.010. So if you wanted to carbonate it, wouldn't the yeast not be able to ferment the priming sugar since it reached it's max attenuation already? I'm assuming max attenuation is the same as alcohol tolerance. Furthermore, if you added wine yeast with priming sugar, which has a much higher tolerance, I'd think it would ferment both the priming sugar and residual sugar so you'd end up with a dry cider and probably bottle bombs. So in summary it seems based on the numbers, you can only get a carbonated cider if you started and end with wine yeasts, and if you wanted it sweet you'd have to back-sweeten with a non ferment-able sweetener. And if you use ale/lager yeasts, you can only end up with still, sweet cider if you let it ferment until it ran out of steam, or you could bottle it before it reaches it's tolerance/max attenuation, but the latter seems like a risky proposition. Another option would be to dilute the apple juice to bring the OG down to about 1.030 but that doesn't sound like a good idea either. Am I understanding this correctly?

 

[UndeadFred]

Ale yeasts have attenuation rates of anywhere between about 60%-80%, and I think S-04 for example max attenuation is 75%. That being the case, if you fermented apple juice/must with an OG of 1.050, it would stop somewhere around 1.010. So if you wanted to carbonate it, wouldn't the yeast not be able to ferment the priming sugar since it reached it's max attenuation already? I'm assuming max attenuation is the same as alcohol tolerance.

No.. they are different.

Alcohol tolerance, or other ways of killing off the yeast (or inhibiting reproduction) is what would stop a yeast from further fermentation. Apparent attenuation is the maximum amount of alcohol produced by the amount of (fermentable) sugars in a wort or must.

What will happen if you hit the Alcohol tolerance point is that you won't get the correct apparent attenuation out of the yeast. It will stall...

There are plenty of ales that are much higher gravity than 1.050! If you add sugar for carbonation your FG after carbonation will go up. No math here, but you might end up at 1.011 instead of 1.010 with the addition of priming sugar when carbonated. Just like beer.

 

[ejcrist]

Ok, got it to a point. So will ale yeast stop converting sugars to alcohol once it reaches it's max attenuation (in theory)? And if so, will the addition of priming sugar not result in carbonation but only additional sugar/rise in gravity like from 1.010 to 1.011 like in your example?

 

[bernardsmith]

Ok, got it to a point. So will ale yeast stop converting sugars to alcohol once it reaches it's max attenuation (in theory)? And if so, will the addition of priming sugar not result in carbonation but only additional sugar/rise in gravity like from 1.010 to 1.011 like in your example?

I may be wrong, but since every sugar in apple juice is fermentable the attenuation will be 100 percent. This is why - I think - that wine yeasts are never described in terms of attenuation. With grains there are many different sugars and some are more and others less fermentable. So all other things being equal the question is whether a specific yeast pitched into a wort with a gravity of say, 1.057 bring the gravity down to 1.010 or 1.015 or 1.005 - and that is important to know if you are adding bittering hops to balance the residual sweetness. In other words, attenuation is a useful metric - for brewers brewing beer.

With wine (and that includes cider), the critical issue is never the final gravity which potentially is always 1.000 or lower. In other words, there is no cultured yeast that cannot ferment bone dry any sugar expressed from fruit. The critical issue is the concentration of sugar before you pitch the yeast ( too high and osmosis cannot take place through the cell walls of the yeast) and the potential ABV (too high and the yeast will not tolerate the concentration of alcohol and will die while there is still sugar unfermented)...Those issues have nothing to do with the sugars themselves. They have everything to do with the wine maker and the ratio of water to sugar he /she has in the must. The yeast's tolerance for alcohol provides that information.

As I say, I may be wrong - I am not an organic chemist and I will happily stand to be corrected

 

[ejcrist]

I agree totally. Thanks BTW for your input. That's why this whole "attenuation" stuff has my head spinning. I'm into wine, mead, and now cider, and I totally understand the alcohol tolerance issue and use it at length in my recipe calculations, but unfortunately beer yeasts don't list alcohol tolerances. I found tolerance ranges on the White Labs website at http://www.whitelabs.com/faq/beer-professional/alcohol-tolerance. It's not very precise but I know the tolerances listed for wine yeasts are just a guide too so that works for me.

So I guess the best thing to do is ignore the attenuation information since I'm not brewing beer and go by the alcohol tolerance ranges. Since I haven't been adding sugar I'm guessing almost all the fermentable sugar contained in the must will be converted to alcohol and it'll finish around 1.000-1.005. Also, since flocculation is high and floculated yeast don't do anything, if I rack once or twice and add priming sugar before bottling, there should be a few suspended yeast left to ferment the additional sugar to carbonate. This is all speculation on my part - just thinking out loud. If anyone has anything to add I'd be glad to hear.

 

[Maylar]

From what I've read, ale yeasts like S-04 and Nottingham are generally good up to 12%. Typical ciders are in the 6.5% range, so we're good to go. My ciders start at 1.050 and will finish between 0.996 and 1.004 depending on yeast and a few other variables. There has always been enough residual yeast to bottle carbonate my ciders even after 2 rackings and a few months time.

Don't sweat the numbers - unless you're wanting a high ABV cider (apple wine), ale yeasts work well.

 

[ejcrist]

Thanks Maylar - appreciate the info. I'm with you on the OG. Mine are all around 1.050 which is where I want 'em. I resort to mead and wine if I want something higher but I like cider in the low range.