room temp storage and oxidation

[aussie brewer]

Hi, i brewed a biscuit blond ale with no dry hops 2.5 months ago,it was brewed in a fermzilla and transferred to a liquid purged keg and lines, also purged the headspace about ten times to get some more o2 out. I left it at room temp (around 18 to 27C fluctuating)
I poured a glass last night and the first thing i could smell was that distinctive aroma of oxidation followed by an oxidised taste.
How long should a beer taste reasonably fresh( no perceviable oxidised flavors or aromas) while being stored at these temps? i know the colder the storage the slower the oxidation
Cheers brewers

 

[VikeMan]

Well, there are too many variables to say how long your particular beer should have remained "reasonably fresh" (which in itself is subjective), but a rule of thumb to keep in mind is that staling reactions tend to happen about twice as fast for each increase in temperature of 10C. So you can estimate that staling was happening at about 4x the rate as it would have at fridge temps.

 

[SEndorf]

I do 10 gallon batches which leaves one keg at room temperature (if not a lager) while the other is served. As long as the room temp keg is purged and under pressure, I've not experienced problems.
Can you describe "distinctive aroma of oxidation followed by an oxidised taste" ? Is it papery cardboard, or something else?

 

[aussie brewer]

I do 10 gallon batches which leaves one keg at room temperature (if not a lager) while the other is served. As long as the room temp keg is purged and under pressure, I've not experienced problems.
Can you describe "distinctive aroma of oxidation followed by an oxidised taste" ? Is it papery cardboard, or something else?

Its difficult to describe,kind of a sweetness that wasnt there before,almost total loss of hop flavour,a real monotone dull flavour. Maybe slightly metallic?

 

[brewbama]

According Charlie Bamforth you did about the worst thing you could do for your beer: Packaging it with O2 and storing it hot.

10 pulls on a PRV is not doing enough to limit post fermentation O2 picked up in transfer to the keg for long term storage.

Now, to fix this beer. You’ll need to get fermentation started again by priming the keg with a sugar solution like you would when you bottle. I may even add some dry yeast just to be sure what will work in theory actually works in reality. The yeast will consume the sugar, the O2, and (theoretically) the compounds that produce the off flavor. You’ve already got stale beer so there’s no harm in spending about five bucks and trying.

In the future: you’ll need to do everything possible to limit O2 post fermentation and store the beer cold to limit staling. I recommend at a minimum:

1. Fill the keg with no foam sanitizer as much as possible and install the lid. Top off completely by using a bottling bucket with a spigot. Run the hose from the spigot to the out post using a black beer disconnect. Ensure the keg is tilted so the gas in post is the highest point. Attach a spare grey gas QD. Open the spigot on the bottling bucket until sanitizer comes out the gas QD. The keg is now full of sanitizer.

2. Use the same hose you filled the keg with but close the spigot, detach it from the bottling bucket spigot, and place the lose end in the bottling bucket. Pressurize the keg with 2-3 psi from a CO2 tank. Leave the QD attached to the gas in post to push out the sanitizer. Install the black beer QD. Once CO2 begins to bubble in the now full bucket of sanitizer disconnect the black QD. Disconnect the gas in QD from the keg.

3. Turn the keg upside down — this is important— by turning it towards the gas in post with the gas in post at the lowest point (slightly tilted). Any remaining liquid should be puddled at the gas in port. Using a spare gas in grey QD, install the QD to allow residual sanitizer to escape. (Shortened gas in dip tube helps with getting all the residual out) When all the liquid is drained quickly pull off the QD. Do not allow all the CO2 to escape. You just purged your keg with CO2.

4. Using the same hose you used to fill and drain the keg, attach the black QD onto the liquid out post and while gas is escaping quickly attach it to the spigot of your fermenter. Tighten hose clamp. You just purged the line with CO2.

5. Attach a hose to the spare grey QD and install it on the gas in post of your purged keg. As CO2 is escaping attach it to the top of your fermenter. You just purged the line with CO2 and created a pretty darn close oxygen free closed loop.

6. Open drain on the fermenter, have a beer. Wait until beer comes out the gas in line. You might have to burp the line at the top of the FV to get things moving. I like to lay my keg on its side with the gas in post high for this. Once the FV has completely drained or beer comes out the gas in post, you now have a full keg of beer that displaced the CO2 in the keg by pushing it into the fermenter. Remove the gas in QD then the beer out QD.

7. Once full, with keg upright and level, apply a small amount of CO2 pressure to the keg and install a tap. Drain a bit of beer until you no longer hear CO2 bubbling in beer (~ a pint or so). You just created CO2 filled headspace.

For bonus points, transfer the beer as described in the steps above with a few points shy of completing fermentation. The airlock should still be bubbling a bit. Once you drain that pint in step 7. attach a spunding valve to the gas side set to ~15 psi. Let the still fermenting beer create CO2 pressure in the keg. The spunding valve will allow excess CO2 to escape. The yeast are consuming any O2 in the beer you may have picked up in transfer.

Did I mention: Store the beer cold or you’ve done all this for nothing.

Hope this helps.

 

[aussie brewer]

According Charlie Bamforth you did about the worst thing you could do for your beer: Packaging it with O2 and storing it hot.

10 pulls on a PRV is not doing enough to limit post fermentation O2 picked up in transfer to the keg for long term storage.

Now, to fix this beer. You’ll need to get fermentation started again by priming the keg with a sugar solution like you would when you bottle. I may even add some dry yeast just to be sure what will work in theory actually works in reality. The yeast will consume the sugar, the O2, and (theoretically) the compounds that produce the off flavor. You’ve already got stale beer so there’s no harm in spending about five bucks and trying.

In the future: you’ll need to do everything possible to limit O2 post fermentation and store the beer cold to limit staling. I recommend at a minimum:

1. Fill the keg with no foam sanitizer as much as possible and install the lid. Top off completely by using a bottling bucket with a spigot. Run the hose from the spigot to the out post using a black beer disconnect. Ensure the keg is tilted so the gas in post is the highest point. Attach a spare grey gas QD. Open the spigot on the bottling bucket until sanitizer comes out the gas QD. The keg is now full of sanitizer. I filled the keg full of sanitizer and the transfer line then purged both with co2? Ill purge the

2. Use the same hose you filled the keg with but close the spigot, detach it from the bottling bucket spigot, and place the lose end in the bottling bucket. Pressurize the keg with 2-3 psi from a CO2 tank. Leave the QD attached to the gas in post to push out the sanitizer. Install the black beer QD. Once CO2 begins to bubble in the now full bucket of sanitizer disconnect the black QD. Disconnect the gas in QD from the keg.

3. Turn the keg upside down — this is important— by turning it towards the gas in post with the gas in post at the lowest point (slightly tilted). Any remaining liquid should be puddled at the gas in port. Using a spare gas in grey QD, install the QD to allow residual sanitizer to escape. (Shortened gas in dip tube helps with getting all the residual out) When all the liquid is drained quickly pull off the QD. Do not allow all the CO2 to escape. You just purged your keg with CO2.

4. Using the same hose you used to fill and drain the keg, attach the black QD onto the liquid out post and while gas is escaping quickly attach it to the spigot of your fermenter. Tighten hose clamp. You just purged the line with CO2.

5. Attach a hose to the spare grey QD and install it on the gas in post of your purged keg. As CO2 is escaping attach it to the top of your fermenter. You just purged the line with CO2 and created a pretty darn close oxygen free closed loop.

6. Open drain on the fermenter, have a beer. Wait until beer comes out the gas in line. You might have to burp the line at the top of the FV to get things moving. I like to lay my keg on its side with the gas in post high for this. Once the FV has completely drained or beer comes out the gas in post, you now have a full keg of beer that displaced the CO2 in the keg by pushing it into the fermenter. Remove the gas in QD then the beer out QD.

7. Once full, with keg upright and level, apply a small amount of CO2 pressure to the keg and install a tap. Drain a bit of beer until you no longer hear CO2 bubbling in beer (~ a pint or so). You just created CO2 filled headspace.

For bonus points, transfer the beer as described in the steps above with a few points shy of completing fermentation. The airlock should still be bubbling a bit. Once you drain that pint in step 7. attach a spunding valve to the gas side set to ~15 psi. Let the still fermenting beer create CO2 pressure in the keg. The spunding valve will allow excess CO2 to escape. The yeast are consuming any O2 in the beer you may have picked up in transfer.

Did I mention: Store the beer cold or you’ve done all this for nothing.

Hope this helps.

According Charlie Bamforth you did about the worst thing you could do for your beer: Packaging it with O2 and storing it hot.

10 pulls on a PRV is not doing enough to limit post fermentation O2 picked up in transfer to the keg for long term storage.

Now, to fix this beer. You’ll need to get fermentation started again by priming the keg with a sugar solution like you would when you bottle. I may even add some dry yeast just to be sure what will work in theory actually works in reality. The yeast will consume the sugar, the O2, and (theoretically) the compounds that produce the off flavor. You’ve already got stale beer so there’s no harm in spending about five bucks and trying.

In the future: you’ll need to do everything possible to limit O2 post fermentation and store the beer cold to limit staling. I recommend at a minimum:

1. Fill the keg with no foam sanitizer as much as possible and install the lid. Top off completely by using a bottling bucket with a spigot. Run the hose from the spigot to the out post using a black beer disconnect. Ensure the keg is tilted so the gas in post is the highest point. Attach a spare grey gas QD. Open the spigot on the bottling bucket until sanitizer comes out the gas QD. The keg is now full of sanitizer.

2. Use the same hose you filled the keg with but close the spigot, detach it from the bottling bucket spigot, and place the lose end in the bottling bucket. Pressurize the keg with 2-3 psi from a CO2 tank. Leave the QD attached to the gas in post to push out the sanitizer. Install the black beer QD. Once CO2 begins to bubble in the now full bucket of sanitizer disconnect the black QD. Disconnect the gas in QD from the keg.

3. Turn the keg upside down — this is important— by turning it towards the gas in post with the gas in post at the lowest point (slightly tilted). Any remaining liquid should be puddled at the gas in port. Using a spare gas in grey QD, install the QD to allow residual sanitizer to escape. (Shortened gas in dip tube helps with getting all the residual out) When all the liquid is drained quickly pull off the QD. Do not allow all the CO2 to escape. You just purged your keg with CO2.

4. Using the same hose you used to fill and drain the keg, attach the black QD onto the liquid out post and while gas is escaping quickly attach it to the spigot of your fermenter. Tighten hose clamp. You just purged the line with CO2.

5. Attach a hose to the spare grey QD and install it on the gas in post of your purged keg. As CO2 is escaping attach it to the top of your fermenter. You just purged the line with CO2 and created a pretty darn close oxygen free closed loop.

6. Open drain on the fermenter, have a beer. Wait until beer comes out the gas in line. You might have to burp the line at the top of the FV to get things moving. I like to lay my keg on its side with the gas in post high for this. Once the FV has completely drained or beer comes out the gas in post, you now have a full keg of beer that displaced the CO2 in the keg by pushing it into the fermenter. Remove the gas in QD then the beer out QD.

7. Once full, with keg upright and level, apply a small amount of CO2 pressure to the keg and install a tap. Drain a bit of beer until you no longer hear CO2 bubbling in beer (~ a pint or so). You just created CO2 filled headspace.

For bonus points, transfer the beer as described in the steps above with a few points shy of completing fermentation. The airlock should still be bubbling a bit. Once you drain that pint in step 7. attach a spunding valve to the gas side set to ~15 psi. Let the still fermenting beer create CO2 pressure in the keg. The spunding valve will allow excess CO2 to escape. The yeast are consuming any O2 in the beer you may have picked up in transfer.

Did I mention: Store the beer cold or you’ve done all this for nothing.

Hope this helps.

Hi Brewbama, i filled the keg full of phosphoric acid solution and the transfer line then pushed it out with co2. I thought that would be enough to keep the beer from being noticably oxidised within a few months? next time ill fill the gas in tube with liquid too and the extra steps you mention!