Interesting German Brewing PDF

[Bassman2003]

I am considering using a bit of lager yeast in every keg to have some sort of oxygen scrubbing going on. Maybe that would help with the CO2 bring O2 in the mix?

Sort of like bottle conditioning but with a keg.

 

[schematix]

For sake of discussion, let's assume my CO2 is <99.9% pure, what could be done to protect the beer? More sulfites? Will the DO content of the beer keep rising the longer its connect to the gas tank?

 

[schematix]

I am considering using a bit of lager yeast in every keg to have some sort of oxygen scrubbing going on. Maybe that would help with the CO2 bring O2 in the mix?

Sort of like bottle conditioning but with a keg.

Yeast only scavenge during active fermentation. So you'd have to have fermentable sugars for it to consume. So i'd say this idea isn't practical.

 

[Bassman2003]

Well, I guess a little sugar would be needed like the bottling process. Seems easy enough.

 

[rabeb25]

For sake of discussion, let's assume my CO2 is <99.9% pure, what could be done to protect the beer? More sulfites? Will the DO content of the beer keep rising the longer its connect to the gas tank?

Try to use a more sulfury German lager strain(never saw what you used) and ferment colder to trap the sulfur.

 

[schematix]

Try to use a more sulfury German lager strain(never saw what you used) and ferment colder to trap the sulfur.

I made the Helles with 2035 (gasp - i know it wasn't what the pdf called for, but it's what i had).... and it was sulfury as hell. Stunk like rotten eggs for a month.

I am going to use 835 for my next several brews. Do you consider this to be a sulfury strain?

 

[rabeb25]

I have never used 835, so I can't comment.

 

[PlinyTheMiddleAged]

So, here's a crazy idea for those that are thinking that CO2 purity may be causing their kegged beers to stale. What if you loaded a canister with oxygen scavenging packets (the food safe kind used for long term storage) and then flowed the CO2 through the canister on its way to the keg?

Here's a link to the O2 absorbers - it's basically instant rust; you add the O2.

Oxy-Sorb Oxygen Absorbers for Food Storage, 100cc, 100-Pack https://www.amazon.com/dp/B0028AG8RO/?tag=skimlinks_replacement-20

Thoughts?

 

[Magnus314]

It's easy enough to natural carb in the keg with added sugars or malt extract, but i have never gotten a clear lager this way, even with extended lagering after carbing.

 

[TheHairyHop]

I think that carbing is less of an issue than serving is. is it possible to put a a gallon or two of wort in a keg with yeast and spunding valve set to a high psi, and then use the resulting gas to serve?

 

[schematix]

So, here's a crazy idea for those that are thinking that CO2 purity may be causing their kegged beers to stale. What if you loaded a canister with oxygen scavenging packets (the food safe kind used for long term storage) and then flowed the CO2 through the canister on its way to the keg?

Here's a link to the O2 absorbers - it's basically instant rust; you add the O2.

Oxy-Sorb Oxygen Absorbers for Food Storage, 100cc, 100-Pack https://www.amazon.com/dp/B0028AG8RO/?tag=skimlinks_replacement-20

Thoughts?

I don't think the concept here is crazy at all. The question to me is whether or not there is an effective and cost efficient product that can do this. I could definitely envision packing a canister full of whatever compound is in those packets (or whatever else) and putting it inline with the co2 stream. Hopefully more info to come on this idea.

 

[schematix]

I think that carbing is less of an issue than serving is. is it possible to put a a gallon or two of wort in a keg with yeast and spunding valve set to a high psi, and then use the resulting gas to serve?

Agree - it's easy to carbonate and keep the keg LODO... it's the introduction of external (non-pure) CO2 that is the issue.

I thought about exactly the situation that you describe but i think to capture a sufficient volume of gas would require a lot of pressure, and probably more than the yeast would be able to handle (>50 psi). I think you could probably spund to like 40 psi and then regulate down, but that keg couldn't be chilled and even though you might get to push 1 or two kegs with it. That's a lot of extra kegs hanging around just for serving gas.

 

[rabeb25]

Can you source somewhere else? I have no problems with my co2 (I get mine from a local gas supplier).

 

[schematix]

Can you source somewhere else? I have no problems with my co2 (I get mine from a local gas supplier).

I could, but how would I know it's not from the same root source that I'm already getting?

 

[Bassman2003]

It's easy enough to natural carb in the keg with added sugars or malt extract, but i have never gotten a clear lager this way, even with extended lagering after carbing.

Good point as the keg is the final stage. Tough problem at the homebrew level.

 

[techbrau]

With the right yeast and fermentation schedule you can get clear lager via spunding. The trick is to choose a strain that attenuates well and then flocculates nicely once the sugar is all gone. Wlp835 and WY2206 are good choices.

It's also a good idea to carry as little yeast as possible into the lagering keg. I ferment at 48-50F nowadays until I have about 2% fermentable extract left. Then I drop by 1-2 f per day until I hit about 45f and there's 1% fermentable extract left. The temp drop will knock a lot of yeast out of suspension and you can rack relatively clear beer into the lager keg. Let the remaining yeast in the lager keg ferment to FG with a spunding valve attached (you'll need slightly higher pressure than 0.8 bar at 45 f) then move to a keezer at 38-42f. You should have clear beer in another 2ish weeks, putting the whole process 4-5 weeks grain to glass.

 

[Bilsch]

I'm not sure how i could quantitatively test the oxygen content of the CO2 though.

This what I would do if you had a DO meter. Prepare via boiling a 5 gal batch of DO water. When cool enough ~180f gently transfer to purged keg. Seal, purge again and seat the cap with a few pounds CO2. Cool keg to room temp and afix a picnic tap. Run a sample out and test for DO content. Record this value. Now chill keg to just above freezing and force carbonate it. Then along the way pull more samples looking for the uptake in O2 if any.

 

[Edelst0ff]

The beer was then held another week at 46F until SG was reached, at which point i started to drop 2F per day until reaching 37F.

Reading this reminds me of my bad experiences where I dropped the temperature too fast during the conditioning phase. There is a high likelihood of thermal shock on the now fragile yeast.

My experience was that it eventually recovered, but then I use a strain that produces a lot of Sulphur: Wissenschaftliche Station 838 (for e.g. WLP 838)

Going on a witch-hunt with CO2 may be futile and time-consuming. Maybe a more careful secondary fermentation would be the remedy?

I cannot guarantee it, but it is something to look into and far less labour intensive than chasing CO2 supplies. (FYI you could consider a 60/40 mix instead of pure CO2 - which is how good pubs push lager out).

Attached are a picture with a sample conditioning schedule from Narziss, Abriss der Bierbrauerei, where you can see the very slow temperature as the beer matures.

The other is how Augustiner serves the Oktoberfest bier from the old barrels with Bavarian "Anstich" (tap?). No gas involved - but then the barrel is emptied the same day.

In my online notes there is is also a example
of the conditioning schedule which illustrates the gradual slow drop.

Hope this helps you with your woes.

 

[KeyWestBrewing]

Someone did all the math on this ITT within the last couple months based on the purity that's reported from the supplier IIRC. I believe the conclusion was force carbing could possibly raise levels over the proposed threshold.
However at the temperature the beer is at during that phase those reactions should take longer than a week. I don't have it at the moment but there's been info from studies posted covering the time it takes for the beer to get oxidized at different temps. You have a bit of a grace period but I think when that clock starts depends when you surpass certain levels. Either way something here isn't clicking to me.

 

[schematix]

I cannot guarantee it, but it is something to look into and far less labour intensive than chasing CO2 supplies. (FYI you could consider a 60/40 mix instead of pure CO2 - which is how good pubs push lager out).

Is there something about a 60/40 blend that is inherently more pure than standard CO2?

 

[doug293cz]

...

I cannot guarantee it, but it is something to look into and far less labour intensive than chasing CO2 supplies. (FYI you could consider a 60/40 mix instead of pure CO2 - which is how good pubs push lager out).

...

Using beer gas (N2/CO2 mix) won't help at all. Equilibrium carbonation level is determined by temperature and CO2 partial pressure. If you reduce the CO2 partial pressure, the carb will go down over time. If you are killing a keg in a day or two, this probably won't matter. But, if you want to serve a keg over a few weeks, you have to maintain the CO2 partial pressure at the equilibrium value for the carb level. If you switch to beer gas, you have to increase the total pressure in order to keep the CO2 partial pressure constant. For example, if you are using 10 psig of pure CO2, that constitutes a CO2 partial pressure of 24.7 psi (absolute pressure = gauge pressure + atmospheric pressure [14.7 psi @ sea level].) If you were to use 60/40 N2/CO2 beer gas instead of pure CO2, the total pressure would have to be 24.7 psia + 24.7 psia * 60/40 = 61.7 psia, or 47 psig. You would get the same amount of O2 in the keg from the "contaminated" CO2 either way. In addition, you would also get additional O2 depending on the O2 contamination level of the N2 supply.

The reason commercial establishments use beer gas to serve lagers is to compensate for long lines, and elevation increases from the storage area, Longer lines and elevation increases force a higher serving pressure in order to maintain the desired pour rates. If you used pure CO2 at the higher serving pressures, the carb level would increase over time.

Brew on

 

[doug293cz]

Is there something about a 60/40 blend that is inherently more pure than standard CO2?

No, see my previous post.

Brew on

 

[Edelst0ff]

My impression was that it is not necessary to carbonate the beer that much once it's connected to the serving lines.

I am not qualified to give you any indication as to the purity of any of the ingredients used, Nitrogen or CO2. But that's what is generally employed by the trade.

Mind you, the pressure they need to use to push it through are much higher than the ones needed for simple dispensing from zero level, so that may be the reason. It may be to avoid over-carbonating the beer.

On the other hand there could be other benefits, but that is speculative.

Without measurements and analysis it's a stab in the dark anyways. I sometimes thought that my Co2 was at fault whereas it effectively was my process.

Up to you. But I hope the awareness of possible thermal shock during conditioning may help you trouble shoot this.

 

[Edelst0ff]

No, see my previous post.

Brew on

Indeed!

Thanks for the trouble explaining this succinctly!

 

[Edelst0ff]

Isn't it interesting that these messages aren't in chronological order?

 

[doug293cz]

Isn't it interesting that these messages aren't in chronological order?

Nothing nefarious going on here. I was writing a response to one of your suggestions when @schematix posted, and it turned out that my response to you happened to answer schematix's question, which I didn't see until after I posted.

Brew on

 

[Bilsch]

I could definitely envision packing a canister full of whatever compound is in those packets (or whatever else) and putting it inline with the co2 stream. Hopefully more info to come on this idea.

I'd be nervous about the iron and its oxide that could come along with the gas stream.

 

[ParanoidAndroid]

Have a question about oxygen and BIAB...

I know BIAB is frowned upon because of squeezing the bag right after the mash. I lose a ton of efficiency points if I don't squeeze (went from 1.036 to 1.045 after squeeze yesterday on an Oat Stout). Could one raise the bag slowly to where it doesn't drip and heat the wort at the same time. Then once the wort starts to boil, start squeezing. Would the boil drive off oxygen once the squeezed wort hits the drained wort?

 

[TexasWine]

Have a question about oxygen and BIAB...

I know BIAB is frowned upon because of squeezing the bag right after the mash. I lose a ton of efficiency points if I don't squeeze (went from 1.036 to 1.045 after squeeze yesterday on an Oat Stout). Could one raise the bag slowly to where it doesn't drip and heat the wort at the same time. Then once the wort starts to boil, start squeezing. Would the boil drive off oxygen once the squeezed wort hits the drained wort?

Something seems odd here. Your pre boil gravity shouldn't increase with squeezing, right?

 

[ParanoidAndroid]

Something seems odd here. Your pre boil gravity shouldn't increase with squeezing, right?

Both gravities were preboil.

1.036 by lifting the bag and gravity draining
1.045 after draining stopped then squeezing the bag, but before wort starts to boil