First Flat Bottles in Years

[yard_bird]

Hi all,
Been brewing for a while and just had my first batch of flat beer in years, though I guess I've updated my process over time.

3.5 gallons Belgian Golden Strong
10# pils
1.5# sucrose
OG: 1.080
FG: 1.005
ABV: 9.8%
IBU:36

Pitched decanted starter of wyeast 3522 at 64F, rose to 78F over the course of fermentation. Held at 78F for a couple days to finish out.

This is where things detract from typical batches: inspired by Mad Fermentationist's New Zealand saison, I added 750mls of NZ sauvignon blanc post fermentation. I then added 4 crushed potassium metabisulfite tablets dissolved in a little bit of DI water for some oxygen protection (bucket fermenter) and cold crashed to 36F for 3 days. This brings the final ABV to 10% . Maybe this is the issue, but 3522 has a 12%ABV ceiling according to wyeast. Maybe the KMS too, but I've been adding this much to my dry-hopped/pale beers for about a year now with no issue (granted all below 7%abv typically).

At bottling, I used this calculator to carbonate to about 2.3 volumes. Little low for style but I've been having some occasional overcarb as well. Based on what I've read around the internet, the beer temp should be the highest temperature the beer reached during fermentation, so I used 78F. Boil priming solution, chill, add to bottling bucket. Rack beer onto bottling bucket, gently mix as it fills, then fill bottles with bottling wand from spigot. Left in the dark at 70F for 3 weeks and a few days in the fridge. Open bottle and there's a tiny hiss and barely any CO2 in solution.

In a sick twist of fate, I brewed a 1.072 OG batch of this with the Duvel strain before I realized the original was flat. So that I don't have flat bottles this time around:
Do I need more conditioning time?
Lower ABV?
Less KMS?
Different beer temperature in priming calculator?
Bottling yeast?

The final product is nearly perfect to me as far as flavor/aroma/appearance.

 

[Skeeter686]

I thought that potassium metabisulfite suppresses yeast activity if it's present in high concentrations, and 4 tablets in a 3.5 gallon batch seems like a high concentration. I could be wrong.

 

[yard_bird]

That might be it. With the wine, the batch is about 3.75 gallons, one tab of KMS/gallon is about 75ppm. The reading I’ve done online says this is more for wild yeast since I guess brewers yeast is either more resilient or otherwise adapted.

I’ll give it another week. Next batch I’ll 1/2 the KMS.

 

[Agent]

My understanding is that something like 1/2-1 tablet of K-meta per 5 gallons is more than adequate to neutralize any O2 picked up during transfer.

 

[dmtaylor]

Yeah, go much smaller on the metabisulfite. I would have used no more than 1/2 tablet, and 1/4 tablet would have probably been sufficient. Your yeast is very tired and very angry. You might see carbonation after a few months, but you might not.

 

[mac_1103]

Your yeast is very tired and very angry.

Tangry?

 

[dmtaylor]

Fno.

 

[yard_bird]

Thanks for the thought out feedback folks, I’ll reduce the KMS this time around. Do you think using 78F for beer temp is accurate for bottling calculations? I held it there for a couple days before cold crashing, so I imagine a lot of CO2 left the beer.

 

[InspectorJon]

I have had this same question about temperature vs. dissolved CO2. If the beer is maintained in a CO2 environment and cold crashed, will it re-absorb CO2? I have come to the conclusion that it will but at a slow and perhaps unpredictable rate. At least not predictable for me. I would like a way to know how to predict that. I think it is related to time an pressure. In my case a mylar balloon wouldn't seem to account for much, if any, pressure.

 

[mashdar]

I have had this same question about temperature vs. dissolved CO2. If the beer is maintained in a CO2 environment and cold crashed, will it re-absorb CO2? I have come to the conclusion that it will but at a slow and perhaps unpredictable rate. At least not predictable for me. I would like a way to know how to predict that. I think it is related to time an pressure. In my case a mylar balloon wouldn't seem to account for much, if any, pressure.

Yes, the equilibrium moves towards higher dissolved CO2 as temperature drops. (Vapor pressure drops faster than gas pressure in headspace.) How fast depends on surface to volume ratio, but probably faster than a keg for most FV. Probably at equilibrium in a few days, I'd guess?

 

[mac_1103]

Do you think using 78F for beer temp is accurate for bottling calculations? I held it there for a couple days before cold crashing, so I imagine a lot of CO2 left the beer.

I have had this same question about temperature vs. dissolved CO2. If the beer is maintained in a CO2 environment and cold crashed, will it re-absorb CO2?

The consensus seems to be that you should use the highest temperature the beer was at in your calculations. The exception being if you crash or lager or bulk age at a lower temperature for an extended period of time (weeks or months). In that case, the beer will absorb a significant amount of CO2 (assuming that you do in fact maintain a 100% CO2 environment in the headspace). HBT's resident physics guru @doug293cz helped me out with the math for that in this thread.

edit - BTW, the beer in question in that thread is probably the best I've ever brewed, and I think the extra carbonation is part of the reason why.

 

[yard_bird]

Great contributions everyone. The CO2/temperature discussion seems sound. I only ever cold crash buckets for 2-3 days.

 

[mashdar]

Great contributions everyone. The CO2/temperature discussion seems sound. I only ever cold crash buckets for 2-3 days.

Do you use any kind of balloon or other means of storing external CO2? You may get some air sucked into the bucket when crashing. Not sure if you've noticed that or care.

 

[yard_bird]

Do you use any kind of balloon or other means of storing external CO2? You may get some air sucked into the bucket when crashing. Not sure if you've noticed that or care.

I’ve considered this in the past, but for me, using a couple tabs of KMS is easier and still effective. I use it on most of my pale/hoppy beers and they hang onto their character for about 6 months, if I hang onto them for that long. Maybe someday I’ll switch to balloons but I have 200 tabs of KMS that should last me a while.

 

[ncbrewer]

The consensus seems to be that you should use the highest temperature the beer was at in your calculations. The exception being if you crash or lager or bulk age at a lower temperature for an extended period of time (weeks or months). In that case, the beer will absorb a significant amount of CO2 (assuming that you do in fact maintain a 100% CO2 environment in the headspace). HBT's resident physics guru @doug293cz helped me out with the math for that in this thread.

The Brewers Friend priming calculator page discusses the effect cold crashing has on dissolved CO2, but they leave it unresolved. From the web page: "However, if the beer was cold crashed, or put through a diacetyl rest, or the temperature changed for some other reason... you will need to use your judgment to decide which temperature is most representative. During cold crashing, some of the CO2 in the head space will go back into the beer. If you cold crashed for a very long time this may represent a significant increase in dissolved CO2. There is a lot of online debate about this and the internet is thin on concrete answers backed by research. We are open to improving the calculator so please let us know of any sources that clarify this point." (The bold font is mine.)

 

[yard_bird]

Greetings all, wanted to provide an update.
Hydrated some CBC-1 and prepped some syringes to add to the bottles. Opened 3 room temp bottles and right away these are more carbonated than they were last I checked. Poured warm sample into a glass and there's CO2 in solution as well.

Added some CBC to a few bottles to check and added an untouched one to the fridge. Will check carbonation sometime soon.