Blending sour beer question regarding FGs

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pursuit0fhoppiness

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Hey all, I'm thinking about making up some small blends in magnums. My question is regarding FGs of the beers and the final carbonation. I've got a beer that's finished at 1.000 and another that's at 1.008 and hasn't moved in two months (it's ~7 months old total). If I do a 1:1 blend of them, will the bugs in the 1.000 beer likely finish off the 1.008 one? If so, I guess I don't need to add any priming sugar and will still end up with >3 vol of CO2. I also have a blend of 10+ Brett strains on hand that I could add some of to the 1.008 just before packaging. I'm hoping to find a way to have the 1.008 beer provide all the sugar needed to carbonate it, rather than add extra priming sugar (partly due to safety concerns, partly cause adding that small of priming sugar could be tricky). Just don't want to go this route and then have it not carbonate at all. Would also consider champagne yeast, diastatic Sacch, etc, but I'd like the beer to continue to develop in the bottle as well. Any thoughts welcome!
 
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pursuit0fhoppiness

pursuit0fhoppiness

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Just realized if I'm doing 50% of each beer, the whole blend would have an average SG of 1.004.. So if all the sugar was consumed, I'd only have about 2 volumes? Is that thinking correct?
 
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brownni5

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When I blend, I use the blending calculator I found at Blending. The link requires that you join the MTF Facebook group, so if that doesn't work, well then, supply more info (volumes, OG, etc) and I or someone else here can do it for you. I'm not smart enough to do it without.

I believe that calculator assumes that the FG will be that of the lowest gravity, in this case 1.000. I always prime with additional champagne yeast, but I know others will use Belle Saison or another Saison strain since they're usually acid-tolerant. Of course, an acid shock starter doesn't hurt either.

Edit: apparently OG and volume don't matter - that calculator comes up with 2.9 volumes in the blend, but it might take forever to get there. I went according to the calculator one time and didn't feel I got the carbonation I was aiming for. Some beers aren't going any lower.
 
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pursuit0fhoppiness

pursuit0fhoppiness

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Thanks for the info! I'm assuming you mean the link to Tonsmeire's calculator on that page. I did play around with that and the updated one by Jeffrey Crane today actually. It does seem like they assume the sweeter beer will fully attenuate, as it said I'd have ~2.8 vol of residual CO2 but that seems high.

Might ponder it more, and maybe just keep adding dregs/Brett and hope that 1.008 beer comes down more so I can confidently bottle and add priming sugar like normal.
 

goodolarchie

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Blending to package is a bit of guess-work. I have some cultures that will eventually eat through a runway tarmac and I know it will reliably get down to 1.003 or lower. The best way I could recommend you find the FG(final) of the blend is to do a small forced fermentation test - enough to get a hydrometer sample. I keep a 100ml flask and finishing gravity hydro around for this exact purpose. It's also helpful to know how fast the remaining brett and sacch will kick off. You can stopper and airlock it with a stir bar if you have a plate. It might take several days, but you'll have something very close to your answer as to what the resultant FG will be.

As to carb volumes, might be better to aim high, add whatever priming sugar you need to hit 3.3vol, and know you might come a bit short. There's nothing sadder than an undercarbed mixed ferm beer in my opinion, the presentation and effervescence is key. I just cracked my 2020 kriek and while it does okay at 2.5vols, I apparently undershot the blend+priming sugar addition despite planning for 3.8volumes, so it's missing a nice cork pop and rocky pillowy head and champagne-like prickly mouthfeel. I had my comeuppance with Belgian beers though, so I'm biased.
 

cactusgarrett

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I asked a similar question here, but didn't get much clarity.

Problem is, as Mike Tonsmeire pointed out in his blog post, the formulas are only exact if the wort for each component is identical. I bottled a saison and a blend with the saison, and ended up getting much lower carbonation in the blend because I used 4oz of priming sugar instead of 7oz as instructed by that excel tool - common sense said I should use the same amount, but the calculator said to use 4oz. I think the idea is that eventually the blend FG will come down to meet the FG of the lower component, but if they were fermented/aged with similar bugs (STA-1 pos sacc, brett, etc.) and one has already reached it's terminal gravity, I don't see how that happens.
 
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pursuit0fhoppiness

pursuit0fhoppiness

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I see what you're saying, if the same bugs/strains were used in each then one would expect them to not ferment the sweeter beer. For mine they're fairly different, plus I added various dregs to each, so I think I'll let my 1.008 beer dry out a bit more then bottle and prime to ~3.2 as usual. Just added a partial pitch of a blend of 10+ Brett strains to it so hopefully that'll take it a bit lower.
 
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pursuit0fhoppiness

pursuit0fhoppiness

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So I think I'll fill the magnum with the two beers, without priming sugar, and put an airlock on it. After a month or two (time for the bugs of the drier beer to finish off the other one), I'll add dextrose directly to the bottle and cap. Does this sound reasonable?
 

monkeymath

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I think in this particular case it's fair to assume an FG of around 1.000 for the blend:
If one was at, say 1.010 and the other at 1.006, then I'd say
"the bugs in the 06-one apparently cannot handle *all* complex sugars either, so the residual extract will depend on the composition of sugars in the wort. Maybe they cannot do anything with the rest in the 10-er and it'll stay at 1.008".
But with the lower one finishing at 1.000, I'd guess those critters will eat just about anything. (And yes, I know that 1.000 is not an absolute zero of sorts, but still...)

What are the two beers in question, anyway?
 
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pursuit0fhoppiness

pursuit0fhoppiness

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Thanks monkeymath, that does seem likely. The two beers are both pilsner/torrified wheat based golden sour beers. The 1.000 one was fermented with a mixed culture blend from Escarpment along with many dregs, and it'll get raspberries after I make this mini blend. The 1.008 one was fermented with spun up 3F Oude Geuze dregs.
 

sweetcell

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That's the one we're referring to - well, indirectly thru Tonsmeire's links. The issue is the formulas are only exact if the wort for each component is identical. It seems to return wonky results when blending two different beers.
what issues have you encountered - carbonation that wasn't inline with the spreadsheet's prediction?

i've used it twice, and both times the spreadsheet provided a good estimate of the beer's final carbonation.

did you put the lower FG beer in the first (left-most) column?
 

cactusgarrett

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I've used it countless times for barrel aged sour beer and it's nuts on for that. I haven't, however, used it for carbonating blends of different beer. In the case i mentioned earlier, I bottled 5gal of a base beer (a funky saison), as well as a 50/50 (2.5gal/2.5gal) blend of that and a different sour. The calculator stated the 5gal of the base saison alone has: 0.43 Residual CO2, and 0.43 Predict CO2 w/o Sugar -> thus needing 7.75 oz table sugar to hit 3.2 vols.

Plugging in the 50/50 blend, though, the sheet stated the combined components have 0.43 Residual CO2 and 1.71 Predict CO2 w/o Sugar -> needing 4.18 oz table sugar to hit 3.2 vols. It assumed the component with the higher FG would come down to meet the lower FG component.

To me, from a practical aspect, blending two similar beers with the same residual CO2 should yield the same "Predict CO2 w/o sugar" as only one component. Because the sheet's limitation is that you're carbonating the same beer just treated differently (aging, fruit, etc.), it's assuming the component with the higher FG will eventually come down to meet that of the lowest FG. But if they're two different beers, it's within reason to assume the higher FG won't drop any further.

In the case above, I did as the spreadsheet prescribed and used 4oz sugar instead of 8oz, and ended up undercarbed as a result.
 
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