Potassium Metabisulphite - to prevent oxidation?

[Worts and all]

Am I missing something here? If you don’t want air in your bottles ,for any reason, real or imagined, can’t you just fill them with beer?

[ben 10]

2 minutes ago, Worts and all said:

can’t you just fill them with beer?

No, you need to purge them with nitrogen in an oxygen free space ship.

[ben 10]

16 hours ago, Otto Von Blotto said:

I use it in my water to get rid of the chloramine

Ascorbic acid works equally as well.

[Shamus O'Sean]

53 minutes ago, Worts and all said:

Am I missing something here? If you don’t want air in your bottles ,for any reason, real or imagined, can’t you just fill them with beer?

Don't think so.  We read that leaving the couple of centimetres of airspace at the top of the bottle allows for expansion of the liquid.  If there is no space for expansion, if the liquid does require more space, bottle fracture seems likely.  Air can be compressed, but liquid, effectively, cannot.

I also wonder about the squeezing technique.  Doesn't the CO2 get into the beer due to the pressure in the bottle.  If the bottle was squeezed before capping, when the CO2 is created wouldn't it just form as a gas, rise to the top of the bottle and expand the bottle to normal shape rather than be dissolved into the beer for release when the cap is popped?  Comments learned colleagues?

[Worts and all]

5 minutes ago, Shamus O'Sean said:

Don't think so.  We read that leaving the couple of centimetres of airspace at the top of the bottle allows for expansion of the liquid.  

I also wonder about the squeezing technique.  Doesn't the CO2 get into the beer due to the pressure in the bottle.  If the bottle was squeezed before capping, when the CO2 is created wouldn't it just form as a gas, rise to the top of the bottle and expand the bottle to normal shape rather than be dissolved into the beer for release when the cap is popped?  Comments learned colleagues?

The point I was trying to make is that the whole thing is too silly for words. Yes, we all know the reason for leaving a small headspace, and someone has decided it is not a good idea. Some brewers,it seems,have too much idle time. Anyhow,I think I need a drink! Cheers!

[Otto Von Blotto]

I think you'll find there's more pressure created than just enough to put the bottle back to its normal shape. Still, I'm not convinced of any benefit to doing it. 

[James Lao]

I suppose I can't really explain why I used to shake the bottle when packaging - stupidity mainly!

I knew that that getting air into the beer was bad,  hence always filling to the bottom of the bottle  /  keg, and when kegging - purge the keg etc.

Just a bad habit of mine done on bottling night,   from the start my brewing adventure that had carried on until reading this thread!

Oh well, at least something has been learned by me from the Coopers forum - yet again.

Cheers

James

[ChristinaS1]

Hop fade is inevitable. It is part of the aging process. Bottlers are at a disadvantage because they have to wait ~2-3 weeks for carbonation. Kegging will buy you 2-3 weeks to consume the beer before hop fade sets in.

There are "oxygen absorbing" crown / pry-off caps are made of resin impregnated LDPE, and there are regular "oxygen barrier" cap liners are made of HDPE, found in cheaper pry-off caps and PET caps. The later are useless in preventing oxygenation....Oxygen absorbing caps are good for one use only. The O2 absorbing resin is activated by wetting / moisture, which can be provided by inverting the bottle once after capping. There is debate about whether O2 scavenging caps can be safely sanitized with a brief dip in Starsan or should be used un-sanitized.

The order in which hop compounds are absorbed into plastic cap liners is as follows: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With oxygen scavenging caps the process is slowed, but not halted. After 55 days (= 7.9 wks), they are at about the same level as oxygen barrier caps. I acknowledge that my re-suable Grolsch bottle caps are likely not helping me in terms of hop fade. If one must bottle, glass bottles with oxygen scavenging pry-off caps are probably the best choice. 

https://pubs.acs.org/doi/full/10.1021/acs.jafc.6b00031?mobileUi=0

Kegs don't have plastic liners, plus the head space can be purged with CO2 or nitrogen. They have the best chance of being consumed before hop fade becomes an issue. 

Cheers,

Christina.

 

Edited October 26, 2019 by ChristinaS1

[ChristinaS1]

@Norris! Given that a block of ice takes longer to melt than an ice cube, I can see why you think a high hopping dose would solve the problem of hop fade; however, I have never read anything to suggest a high starting dose slows the process; I stand to be corrected of course.

Pretty sure oxidative stability depends on 1.) minimal cold side aeration, 2.) how the beer is packaged, 3.) whether or not it is pasteurized, and 3.) if it is kept cold. Certain trace minerals can also speed up oxidation: copper, iron, manganese. Makes me wonder about those copper immersion chillers....I recently learned ground water in my area is high in manganese. Flaked oats are high in manganese, as is flaked wheat; malted versions are lower in manganese. 

Just speculating but I suppose a high starting dose does mean higher doses of things at the end of the fading sequence: linalool, α-terpineol, and geraniol. 

Cheers,

Christina.

Edited October 27, 2019 by ChristinaS1

[BlackSands]

9 hours ago, ChristinaS1 said:

Hop fade is inevitable. It is part of the aging process. Bottlers are at a disadvantage because they have to wait ~2-3 weeks for carbonation. Kegging will buy you 2-3 weeks to consume the beer before hop fade sets in.

There are "oxygen absorbing" crown / pry-off caps are made of resin impregnated LDPE, and there are regular "oxygen barrier" cap liners are made of HDPE, found in cheaper pry-off caps and PET caps. The later are useless in preventing oxygenation....Oxygen absorbing caps are good for one use only. The O2 absorbing resin is activated by wetting / moisture, which can be provided by inverting the bottle once after capping. There is debate about whether O2 scavenging caps can be safely sanitized with a brief dip in Starsan or should be used un-sanitized.

The order in which hop compounds are absorbed into plastic cap liners is as follows: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With oxygen scavenging caps the process is slowed, but not halted. After 55 days (= 7.9 wks), they are at about the same level as oxygen barrier caps. I acknowledge that my re-suable Grolsch bottle caps are likely not helping me in terms of hop fade. If one must bottle, glass bottles with oxygen scavenging pry-off caps are probably the best choice. 

https://pubs.acs.org/doi/full/10.1021/acs.jafc.6b00031?mobileUi=0

Kegs don't have plastic liners, plus the head space can be purged with CO2 or nitrogen. They have the best chance of being consumed before hop fade becomes an issue. 

Cheers,

Christina.

 

Good point about the bottlers disadvantage -  that 2 -3 week wait time is significant.   I do wonder if bottlers are in fact fighting a losing battle. It was interesting to note Prof Bamforth re-confirming cans as the package of choice for beer stability.  Trouble is, canning machines are well beyond the budgets of most homebrewers!  I'm using PET's and also swing-top glass, probably the worst two options as you suggest.   I haven't invested in crown caps and a capper, though I do have a collection of 500ml bottles.  Maybe I should, and do a PET vs Flip-Top vs standard crown cap comparison one day.  I've never seen the O2 scavenging ones in stores here though.

[ChristinaS1]

@BlackSands I did a flip-top vs crown cap comparison some time ago. I thought I could taste a difference, but it was not a blind triangle with multiple tasters. PET bottles were not part of the test, as I don't use them. 

I would be surprised if you don't have O2 scavenging caps in stores near you. Those cold activated ones that turn blue when it gets cold enough to drink are usually O2 scavenging, but not all of them have that cold activated technology.

Besides using glass crown cap bottles with O2 scavenging bottles the only other thing a bottler can do to get hop flavour to last longer is get a chest freezer to store bottled beer in. You have mentioned you don't have room for one in the house, but it could be kept outside in a climate like yours. Plus, if you ever have enough space or money for a kegging system, you'd be part way there. 

Cheers,

Christina.

 

Edited October 27, 2019 by ChristinaS1

[BlackSands]

15 hours ago, ChristinaS1 said:

Besides using glass crown cap bottles with O2 scavenging bottles the only other thing a bottler can do to get hop flavour to last longer is get a chest freezer to store bottled beer in. You have mentioned you don't have room for one in the house, but it could be kept outside in a climate like yours. Plus, if you ever have enough space or money for a kegging system, you'd be part way there. 

Nice Idea, but sadly it aint gonna happen!  The only available space was the garage, which is already where I have my fermentation fridge and other brewing gear.   Because I also have a good amount of stuff stored in there besides there's simply just no room for anything else.   And even if I did have the space, the cost of kegs, plus CO2 bottle & regulator,  fridge and fittings etc all adds up to a number that's hard for me to justify when there's other priorities to consider.   

[Otto Von Blotto]

What could possibly be more important than great tasting beer?

[Beer Baron]

18 minutes ago, Otto Von Blotto said:

What could possibly be more important than great tasting beer?

Great tasting beer + sport + BBQ!!

[ChristinaS1]

A little update on the batch I added the SMB. It is now five weeks and three days since it was kegged. I have been noticing in the past couple of days that the hops are fading, right on schedule.  The SMB did not delay it. So for me the experiment was a fail too. 

Luckily, since this batch was kegged, it is almost gone now.

Cheers,

Christina. 

[BlackSands]

On 11/1/2019 at 2:44 PM, ChristinaS1 said:

A little update on the batch I added the SMB. It is now five weeks and three days since it was kegged. I have been noticing in the past couple of days that the hops are fading, right on schedule.  The SMB did not delay it. So for me the experiment was a fail too. 

So...   is oxygen really the culprit then?   SMB plus a CO2 purged keg and the aroma still fades that quickly suggests there's perhaps more to it...    

[PaddyBrew2]

In regards to hop fade. Here’s two pics. Taken approximately 3 months apart

first pic is my very first AG brew. Mosaic and Citra IPA. Amazing aroma and taste. Very hop forward. Small bit hazy

 

next pic is the last bottle I cracked tonight of it. Clear as day. But not as hop forward as the above but still a great hop presence in terms of aroma and taste
 

 

clarity doesn’t bother me as it tasted better when hazy but only natural that the taste fades after a prolonged period even with 200 gms of hops all up. 

[ChristinaS1]

@PaddyBrew2 Thanks for that. When you say "200gm of hops all up," do you mean in the dry hop, or altogether?

What kind of bottle did you use, PET or crown cap glass?

Thanks,

Christina. 

[PaddyBrew2]

just checked the recipe, was 100 gm dry hop. used the PET bottles. interestingly enough, the clear pic above came from the one and only glass bottle as i used as it was the last drop from the FV

[James Lao]

This weekend had my few bottles that were not shaken on bottling / kegging night.

No surprises I suppose the beer is probably the best I have had out of one of my bottles.

Usually always prefer the kegged version by a mile but not sure with this one.

Doesn't look as dark either compared to previous batches.

So for me that is a definite bad brewing habit put to bed!

Cheers

James

[BlackSands]

Here's some more very recent info on this topic:

Quote

Based on my experience with this xBmt, I now feel more comfortable using higher amounts of SMB at packaging without fear of my beer developing a sulfur off-flavor. To me, this method is an easy and affordable way to reduce the risk of beer being ruined by cold-side oxidation.

 

http://brulosophy.com/2020/04/06/impact-higher-dosage-rates-of-sodium-metabisulfite-smb-have-on-beer-character-exbeeriment-results/?

 

 

[BlackSands]

And even more on this topic...

http://brulosophy.com/2020/03/23/cold-side-oxidation-impact-of-dosing-beer-with-potassium-metabisulfite-pmb-at-packaging-exbeeriment-results/

[ChristinaS1]

21 hours ago, BlackSands said:

And even more on this topic...

http://brulosophy.com/2020/03/23/cold-side-oxidation-impact-of-dosing-beer-with-potassium-metabisulfite-pmb-at-packaging-exbeeriment-results/

He has misnamed this experiment. He has not tested the effectiveness of PMS in reducing cold side-oxidation. He should have used un-purged kegs, as he did when he tested the SMB.

Perhaps he should do a head to head comparison of PMB and SMB and, if people can taste a difference, see which they prefer.

Cheers,

Christina.

 

[BlackSands]

1 hour ago, ChristinaS1 said:

He has misnamed this experiment. He has not tested the effectiveness of PMS in reducing cold side-oxidation. He should have used un-purged kegs, as he did when he tested the SMB.

Perhaps he should do a head to head comparison of PMB and SMB and, if people can taste a difference, see which they prefer.

Yes, I saw in the comments that this was also mentioned.  Seems like a fairly fundamental blunder to me!  

[Otto Von Blotto]

I'm not sure why there would be much difference in the performance between the two. It's not the sodium or potassium that removes the oxygen. Possibly some differences in flavour though