91% attenuation in table beer!?!?

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dan125

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I racked a low ABV brew out of the FV yesterday, and having taken a gravity reading I'm a bit worried.
Its gone from 1.037 to 1.003 in 2 weeks, which is 91% attenuation!

This was mashed at 66C, and there's no sugar in the recipe.
Fermented with san diego super yeast - 2nd gen (1.5L starter made using saved yeast overbuilt from previous starter)

It tasted nice enough, but I'm worried the high attenuation might point to an infection, especially as I pitched the yeast cake straight into a new brew.

What do you reckon?
:cheers:
 
Just seen the thread along very similar lines - looks like I may have a wild yeast problem too then
 
It might not be mate. Some yeast strains can attenuate more when they are on a 2nd/3rd generation. And it is super yeast so mega attenuation isn't a surprise.

I would say bottle it and see. Just make sure you mega clean all your kit afterwards and don't end up with a ingrained infection like me.


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It might not be mate. Some yeast strains can attenuate more when they are on a 2nd/3rd generation. And it is super yeast so mega attenuation isn't a surprise.

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Ta hoddy, that's what I'm crossing my fingers for, as it'll be 2 ruined brews if not.
I'll dry hop this week & keg next w/e as planed and see how it goes
 
San Diego super is a mental yeast, it does go low. Did you taste when it when you racked? The time I had a wild yeast infection it was very apparent as soon as I tasted it.
 
Its gone from 1.037 to 1.003 in 2 weeks, which is 91% attenuation!

Hmmmm, i've never really thought about this before, just checked my last few brews and they all seem on the high side, 80%+ and some 90%+.
The beers taste great and definitely no sign of an infection, i'm ultra cautious with my cleaning routine, however i've never given attenuation a thought, didn't even realise what it meant until I looked into it.
How can I change the percentage if the beer drops to the FG reading after fermentation all by itself ??
Do I need to worry if my beer is good at doing it's own thing and the results are good ??
Cheers. :thumb:
 
If you beer tastes good, then I'd say don't worry.
91% is just more than I'm used to or was expecting.
If its not infected then its not really a problem, but will be a drying finishing beer, with a higher ABV than I planned.
 
Did you taste when it when you racked? The time I had a wild yeast infection it was very apparent as soon as I tasted it.

As it happened it was a big batch, and I couldn't fit it all in the carboy, so had a little more than a taste. It tasted fine & not even very dry.
 
Kegged/bottled this brew last night after a week in the 2ndry inc 5 days dry hopping its dropped another point to 1.002 making 94% attenuation!

I had an unusual aroma (I want to say appley - but hard to describe). Didn't taste rank but not great. I'll give it a week in the keg and try it but I'm not holding out a lot of hope.
 
Kegged/bottled this brew last night after a week in the 2ndry inc 5 days dry hopping its dropped another point to 1.002 making 94% attenuation!

I had an unusual aroma (I want to say appley - but hard to describe). Didn't taste rank but not great. I'll give it a week in the keg and try it but I'm not holding out a lot of hope.

Apple is fine. It's the biproduct of yeast. Let it condition in the keg for a month or so.
Don't worry about attenuation. From 1.030 something to 1.002 is only .030 points. Let's just say that you mashed low temp and got very high fermentable sugars. I had one drop to .1 Plato which is about that level. I kind of mash low because I mostly like dry beers.
 
Apple is fine. It's the biproduct of yeast. Let it condition in the keg for a month or so.
Don't worry about attenuation. From 1.030 something to 1.002 is only .030 points. Let's just say that you mashed low temp and got very high fermentable sugars. I had one drop to .1 Plato which is about that level. I kind of mash low because I mostly like dry beers.

Thanks JB
Couldn't resist a sample of this tonight after 4 days in a corny (just to check the carbonation of course :whistle:)
I'm pretty sure its not infected. Its dry but not super-dry - a bit thin though, but I don't mind this as its meant to be a quaffing ale - just coming in at 4.6% rather than the 4.0% I planned on.
I now think the flavour I thought was apple is in fact the Nelson Sauvin hops overpowering the others, might be wrong though - didn't think I used that much.
Will be interesting to see the attenuation on the brew I pitched the yeast cake from this into when I rack it tomorrow night.
:cheers:
 
Maybe check the accuracy of your thermometer. If it was a few degrees out and you were mashing at 63 or 64 degrees you might have created a more fermentable wort.
 
If you're happy with it, then no need to do anything. If you think it's horrible you could try a little lactose to sweeten and add mouthfeel.
 
For some high attenuation is expected. Those brewing the increasingly popular "Saisons" expect FGs of 1.002 or thereabouts. My first venture into "Saison" yeasts is resulting in a beer of FG 0.999 after 5 days; surely it wont go lower? Beersmith is suggesting an impossible attenuation of 102.7%. But I'm not going to be worried about "wild yeast" infections. It tastes fine just dry like I could never have expected a beer could be, so I will be accepting that it's "just one of those things" and enjoy it for what it is and not what I thought it would be.
 
I've been getting really low FG readings consistently with re-used US05 for some time now. I got 9 250ml bottles from a cake back in August and have been using them on every brew since. The last bottle I used was the one that took the longest to drop out and it did not flocculate well at all. No doubt due t o being trub - selected and not selected for flocculance by top-cropping.

Anyway, that aside, I put down the high attenuation to factors such as:

Leaving the beer in the FV for 2 weeks and then racking to secondary for a further week, before taking a reading.

Relying overly on Star San for sanitation (which does not kill yeasts).

Using equipment that may have residual Belgian Ale yeast from the 2016 Xmas brew started in January using a Brewferm kit.
 
When your finished with a brew you really got to clean everything well with some kind of acid clean or caustic. Oxiclean clean isn't that but it boosts the ph to as high as 11 and since hydrogen peroxide is the main ingredient it works well. Just rinse well. The good thing too is it's a sanitizer so no need to sanitize right after washing.
 
Maybe check the accuracy of your thermometer. If it was a few degrees out and you were mashing at 63 or 64 degrees you might have created a more fermentable wort.

Thanks Simon - this had crossed my mind and I'll try to check it before tomorrows brew. I've never had the gravity drop this low before but its worth checking.
The brew I pitched the yeast cake into has gone from 1.048 to 1.002 so far - don't think I'll be re-using this yeast again:-



:cheers:
 
If you're happy with it, then no need to do anything. If you think it's horrible you could try a little lactose to sweeten and add mouthfeel.

I might well try that in the pale ale thanks, if I can lay my hand on some lactose - oh for a more LHBS!
 
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