Bottling a sour before terminal (currently 1.005, expected terminal is 1.000-1.001). How risky?

[tyrub42]

Hi everyone! Long story short, I have a sour that is currently sitting at 1.005. It's been aging for 3 months so far, but the brett doesn't like to do very much until springtime when the temperature rises, and I'd like to get something else in that fermenter. Due to this recipe and yeast being very similar to ones I've used before, I can say with a decent amount of certainty that terminal will be 1.000-1.001. After sitting in the fermenter for awhile, I'm guessing that it currently has 0.5-0.7 volumes of co2 in it (I added passionfruit two months ago which restarted active fermentation, so it's been sitting for about two months with nothing feeding it), the the final product should end up with 3-3.7 volumes. My questions are basically:

1. Is there any reason to suspect any extra co2 might make it in there? OG was only 1.040 so I don't think there's much chance of it going under 1.000, but would love some second opinions

2. Is there a strong possibility that the bugs chew away at it rather than the brett, and don't produce much co2?

I have one buddy who bottled a wonderful fruited sour, but didn't add bottling yeast, and instead of the wild yeast in the beer chewing up the bottling sugar to carbonate it, the pedio chowed down on it, didn't produce any co2, and instead produced a ton of extra acidity. Naturally this would be a bad thing to happen to my beer, but I'm thinking because it won't be simple sugars, but instead longer dextrins, the brett should be what takes it down, and should produce co2. Does this sound right?

Thanks so much for the help, cheers!

Tyler

 

[BrewSomeMore]

Not all Bretts ferment dry so it could possibly be done. Usually I bottle mixed fermentation in thicker bottles just in case there is some residual gravity.

 

[BrewSomeMore]

Your buddies fruited sour probably was too acidic meaning the added fruit lowered the PH too much and there wasn't enough active yeast to carbonate it. It's a always good to add bottling yeast in a sour to get consistent carbonation. Now I always use bottling yeast on sours after inconsistent results without.

 

[tyrub42]

Not all Bretts ferment dry so it could possibly be done. Usually I bottle mixed fermentation in thicker bottles just in case there is some residual gravity.

Sorry, I should have noted that I also have thick bottles that can easily handle 3.5 vol. They're not Orval-thick, but they're about halfway between an ordinary 355ml glass beer bottle and an orval bottle (I actually weighed them all and it was right around halfway).

I should note, though, that this beer will absolutely ferment out. I honestly don't see much chance of it ending higher than 1.001 due to grain, mash temp, and previous experience with this yeast (Roeselare plus bottle dregs). It even has some local wild yeast from a friend which generally ends at or below 1.000, although we'll see.

BTW do you know of anywhere you can check the lowest possible FG for a given OG? This was 1.040, so I'm guessing 0.999-1.000 is the lowest possible, but if there's potential for it to get several points lower, I'd probably opt against this plan haha.

Thanks a lot!

 

[tyrub42]

Your buddies fruited sour probably was too acidic meaning the added fruit lowered the PH too much and there wasn't enough active yeast to carbonate it. It's a always good to add bottling yeast in a sour to get consistent carbonation. Now I always use bottling yeast on sours after inconsistent results without.

IDK if the fruit did it, as the beer's acidity was mild and perfect at bottling after the fruit had already been added, but like you said, he didn't add bottling yeast, and the brett was probably just too lazy by that point to really take hold of the sugars. He now adds it to all of his sours, but what a bummer to learn that lesson the hard way on such a spectacular beer. It had that elusive 'tart jam' profile with such a wonderful complexity, and ended up uncarbed and bitingly sour

 

[tyrub42]

cancel this post, I just exposed my terrible math skills

 

[VikeMan]

BTW do you know of anywhere you can check the lowest possible FG for a given OG? This was 1.040, so I'm guessing 0.999-1.000 is the lowest possible, but if there's potential for it to get several points lower, I'd probably opt against this plan haha.

If we ignore "insignificant" gravity contributions from proteins and other non-carbs...

100% real attenuation = ~122% apparent attenuation
0.040 x 122% = 0.0488
1.040 - 0.0488 = 0.9912 = ~0.991

But I doubt it will get that low.

 

[tyrub42]

If we ignore "insignificant" gravity contributions from proteins and other non-carbs...

100% real attenuation = ~122% apparent attenuation
0.040 x 122% = 0.0488
1.040 - 0.0488 = 0.9912 = ~0.991

But I doubt it will get that low.

Thanks! Wow that is way lower than I would have thought. I also don't see it getting that low, but I guess that does certainly mean there's significant risk involved with my little plan...

 

[BrewSomeMore]

IDK if the fruit did it, as the beer's acidity was mild and perfect at bottling after the fruit had already been added, but like you said, he didn't add bottling yeast, and the brett was probably just too lazy by that point to really take hold of the sugars. He now adds it to all of his sours, but what a bummer to learn that lesson the hard way on such a spectacular beer. It had that elusive 'tart jam' profile with such a wonderful complexity, and ended up uncarbed and bitingly sour

Just have to learn the hard way sometimes. You can always brew more but it does kinda suck when you spent all that time on a complex sour only to have no carbonation. I've had commercial sours that have little or no carbonation intentionally. Some of those are real sour and can only drink 375ml worth before my esophagus erodes.

 

[tyrub42]

Just have to learn the hard way sometimes. You can always brew more but it does kinda suck when you spent all that time on a complex sour only to have no carbonation. I've had commercial sours that have little or no carbonation intentionally. Some of those are real sour and can only drink 375ml worth before my esophagus erodes.

Totally. He still kept those beers, and they still got consumed, but it was the worst way to 'learn' that lesson (he already knew he should add bottling yeast, but we all get a little lazy sometimes and skip a step that we think isn't totally necessary here and there). At it's peak, that was a beer I would have happily chosen over 99 percent of commercial sours. With how it ended up, it lost its jamminess, its balance, and became a bit of a chore to drink if you didn't have someone to share the bottle with. It started out with a cantillon geuze level of acidity, and ended up with a level closer to the sourest Cascades