Potassium Metabisulphite - to prevent oxidation?

[Otto Von Blotto]

I think you'll find it's SO2, SO4 is sulphate, not sulphur dioxide

[ChristinaS1]

5 hours ago, Norris! said:

One bit of advice, try limiting the number of changes to the process to allow for a clear understanding of the effects of the change and then you can determine if it is worth it to incorporate or not.

That is very good advice, and I know that is what I should do. The trouble is I get excited and want to try stuff right away; I just can't resist. I am too impatient! Then sometimes I have to go back and re-brew, dropping one of the changes. When will I ever learn? 

Cheers,

Christina.

Edited September 30, 2019 by ChristinaS1

[Norris!]

2 minutes ago, ChristinaS1 said:

That is very good advice, and I know that is what I should do. The trouble is I get excited and want to try stuff right away; I just can't resist. I am too impatient. Then sometimes I have to go back and re-brew, dropping one of the changes. When will I ever learn? 

Cheers,

Christina.

I think we are all the same in the that regard. The best laid plans...of mice and brewers, right. Either way, if hop fade is the biggest concern, then I would say your brews are alright and everything else is just refining, which we all do, well at least I do, constantly.

I have no doubt about your brewing skills and knowledge, that is for sure.

Cheers

Norris

[BlackSands]

On 9/30/2019 at 1:37 AM, ChristinaS1 said:

There is a distinct aroma and flavour of sulphur, similar to a lager, which is competing with the hops.

Well, I've just poured a bottle of the golden ale into a serving jug, and yes... definitely got a hit of sulphur this time.  Not sure why I didn't notice it previously.  I do think I normalise it fairly quickly though.  As I work my way through the glass of beer I'm much less aware of it.  And... if I called this golden ale a lager instead, then problem solved!   

Anyway, it is a bit of a spoiler now that my attention is focused on it.  I guess the options are: 

1. save it for stronger flavoured beers (like the NEIPA Brulosophy tested it on)  
2. reduce the dose ( 1/2 campden?) or... 
3. just forget about it  

I'll leave it out of the next batch I think but one thing I will start doing with PET bottles from now on is squeezing out the air before tightening the caps. 

Edited October 2, 2019 by BlackSands

[ben 10]

3 hours ago, BlackSands said:

just forget about it  

I have not ever had an oxidised home brew.....

[ChristinaS1]

7 hours ago, BlackSands said:

Well, I've just poured a bottle of the golden ale into a serving jug, and yes... definitely got a hit of sulphur this time.  Not sure why I didn't notice it previously.  I do think I normalise it fairly quickly though.  As I work my way through the glass of beer I'm much less aware of it.  And... if I called this golden ale a lager instead, then problem solved!   

Anyway, it is a bit of a spoiler now that my attention is focused on it.  I guess the options are: 

1. save it for stronger flavoured beers (like the NEIPA Brulosophy tested it on)  
2. reduce the dose ( 1/2 campden?) or... 
3. just forget about it  

I'll leave it out of the next batch I think but one thing I will start doing with PET bottles from now on is squeezing out the air before tightening the caps. 

Squeezing PET bottles sounds like a great idea.  Low hanging fruit. 

I have read that wine makers sometimes use a SMB solution, made with 12.5gm/L of the powdered stuff, to rinse bottles. Apparently it leaves 2-3ppm of SO2 behind and is no rinse. I might give that a try next time I have to bottle beer that won't fit in my keg. But I won't be adding a Campden tablet to the whole batch again. I don't think the part that gets kegged needs it, and that is even more true now that I am set up for doing closed transfers. 

In terms of bottling, this thread has completely changed my opinion on bulk priming. I am now a firm convert to bottle priming (for those times when I still need to bottle). Racking to a bottling bucket adds oxygen, and trying to stir a sugar solution into the primary also risks introducing oxygen. Then there is the issue of inconsistent carbonation levels with bulk priming. Even though I used a bottling bucket and added the priming solution to the bottling bucket before transfer, and stirred afterwards, I still found my carbonation levels inconsistent. In retrospect I can't believe I put up with the inconsistent carbonation levels for so many years, before trying bottle priming. 

Cheers,

Christina.

 

Edited October 2, 2019 by ChristinaS1

[BlackSands]

4 hours ago, Ben 10 said:

I have not ever had an oxidised home brew.....

I reckon some have, and wouldn't actually know.  I've definitely had a batch or two in the past get darker over time... but I never actually tasted anything taht suggesting it was oxidised.  Anyway, the main purpose of this wee trial was more about preserving hoppiness rather than oxidisation itself though the two are related.

 

9 minutes ago, ChristinaS1 said:

In terms of bottling, this thread has completely changed my opinion on bulk priming. I am now a firm convert to bottle priming (for those times when I still need to bottle). Racking to a bottling bucket adds oxygen, and trying to stir a sugar solution into the primary also risks introducing oxygen. Then there is the issue of inconsistent carbonation levels with bulk priming. Even though I used a bottling bucket and added the priming solution to the bottling bucket before transfer, and stirred afterwards, I still found my carbonation levels inconsistent. 

I do both, but I can't say I have a problem with carbonation inconsistency... even when priming in the primary as I tend to do now.   I do leave the the beer for quite a while though to allow the sugar solution to fully disperse into the beer.   After bulk priming the golden ale above it was then left for over two hours before bottling thanks to an unscheduled visitor who arrived just as I was about to start !  Normally I'd allow 30 - 60 mins.   

[ben 10]

30 minutes ago, ChristinaS1 said:

In terms of bottling, this thread has completely changed my opinion on bulk priming.

I bulk primed my Flanders and will do so with the next one. Only time I have.
And I neede to because it needs to be heavily carbed.

[ChristinaS1]

39 minutes ago, Ben 10 said:

I bulk primed my Flanders and will do so with the next one. Only time I have.
And I neede to because it needs to be heavily carbed.

So you bottled that Flanders Ben? Did you bulk prime in the primary or rack to a bottling bucket? I will be curious to hear if you end up noticing inconsistent carbonation between bottles.

Perhaps BlackSands method of waiting for 30-60 minutes would have solved my inconsistent carbonation issue, but I never even thought of that. I was always eager to get the process over with ASAP.   

As you know I racked to a bottling bucket, a process that took time and dirtied another carboy, which then had to be cleaned, which took more time, plus water. Bottle priming is more fiddly and hands on, but there is no clean up....If bulk priming in the primary, those things don't apply.

I should clarify that when I say I have completely changed my opinion on bulk priming, I am talking about bottling. I will actually continue to bulk prime some of my kegged batches. 

Cheers,

Christina.

Edited October 2, 2019 by ChristinaS1

[Otto Von Blotto]

I never had inconsistent carbonation when I bulk primed bottles. Never noticed any signs of oxidation either. Maybe the yeast scavenged it, maybe my technique didn't really introduce any to begin with, maybe a bit of both. I don't really know why, but if I did ever notice any issues I would have taken steps to prevent them occurring again. 

The only ones I did notice it in were 6 year old bottles I found in the garage last year. They had a definite sherry like flavour to them. I vaguely remember the batch when I drank the rest back after it was bottled and it didn't taste like that then. It's something you notice and remember. 

Edited October 2, 2019 by Otto Von Blotto

[ben 10]

7 hours ago, ChristinaS1 said:

So you bottled that Flanders Ben?

I did, wanted to keep Brett away from the kegs. And I did rack as the fv for the Flanders is a demijohn.
No issues with inconsistent carbonation.

[BlackSands]

11 hours ago, ChristinaS1 said:

As you know I racked to a bottling bucket, a process that took time and dirtied another carboy, which then had to be cleaned, which took more time, plus water. Bottle priming is more fiddly and hands on, but there is no clean up....If bulk priming in the primary, those things don't apply.

I do recommend you give bulk priming in the primary a go.  As mentioned elsewhere I've had great success with this and the big advantage is it avoids all the hassle you mention.  Certainly with CC'd beers and high-flocc yeast strains it really has proven to be a very effective and time-efficient way to do it.  I only wish I'd caught onto it years ago! 

11 hours ago, ChristinaS1 said:

Perhaps BlackSands method of waiting for 30-60 minutes would have solved my inconsistent carbonation issue,

Yes, I'm sure this is an important step... give the sugar plenty of time to disperse.   

[BlackSands]

On 10/2/2019 at 3:56 PM, BlackSands said:

Well, I've just poured a bottle of the golden ale into a serving jug, and yes... definitely got a hit of sulphur this time. 

I've changed my mind again!  No sulphur.  

I took a sample of my currently CCing brew to see how the clarification was progressing and I noticed the same aroma... except there's no k-met in this beer.  I think what I'm detecting is actually yeast-related, not sulphur from the k-met.   I've just poured another of the Pacific Ale and yeah... I get an initial hit of that same aroma, and now with the idea of yeast in my mind, that's what I think it is. And...  it very soon fades away, or I very quickly normalise it.   5 minutes later I can't detect it at all in the glass.  Curious.  

[BlackSands]

Well...    I'm gonna call this sodium-metabisulphite experiment a fail!

The second brew that I added k-met to at packaging was a tasty NZ Pale Ale.  It didn't appear to suffer from any hint of sulphur aromas that were an issue for @ChristinaS1 and a hint of a problem in my golden ale.  This NZPA in contrast was clean and suitably hoppy in both flavour and aroma and I've been slowly, with help, working my way through the batch.   

The idea behind adding the small dose of k-met at bottling, based on a bit of research, was to achieve several things :

• - reduce any possible oxidation that may occur
• - help preserve hop flavour and aroma
• - kill any potential spoilers - bacteria, wild yeast etc

However, the remaining third of this NZPA has just recently and very quickly turned into gushers.  Something has taken hold and continued to attenuate them dry resulting in over carbonation.  Clearly the SO2 hasn't dealt to whatever contaminant had found its way into this one!     

There was curiously however still a couple of bottles (PET) left in the batch that didn't feel super hard like the others so I poured one of those for evaluation.  It seems to be intact, the beer pours fine and generally seems to have been unaffected by whatever has got into the remainder of the batch.  However, it's clear that already the hop aroma has diminished quite a bit... pretty much consistent with my usual experience with hoppier beers.  The flavour is there... but without the 'nose' it's now much less of a beer than it was just a week or two ago.   So, again it looks like the SO2 has had no real benefit.  

It was worth a try I guess.....   

 

[ChristinaS1]

@BlackSands Thanks for the update. It was worth a try. Too bad it didn't work. 

I suppose some commercial breweries have experimented with this as well and, the fact that it isn't an industry standard may not be an accident.

Cheers,

Christina.

[Otto Von Blotto]

Yeah, it's almost as if commercial breweries know what they're doing...

It was interesting to read about but I had a suspicion it wouldn't really work that well if at all, for the simple reason that no commercial breweries do it. 

[ChristinaS1]

@BlackSands I am still drinking that beer I added SMB to. A few days ago I noticed the sulphur flavour was starting to fade, and today it is gone. Whatever caused it, time healed it. It is tasting pretty good now and still has some hop aroma. Kegged it on Sept 23, so four weeks ago. Not sure it will last beyond the five week point, which is when I usually start complaining of hop fade, so I may never know if it helped or not. 

Cheers,

Christina.

[BlackSands]

4 hours ago, Otto Von Blotto said:

Yeah, it's almost as if commercial breweries know what they're doing...

It was interesting to read about but I had a suspicion it wouldn't really work that well if at all, for the simple reason that no commercial breweries do it. 

@Otto Von Blotto Incorrect!  I understand it's actually fairly common practice in some of the bigger commercial breweries.  Here's an abstract from a 2016 paper that reviews current roles and regulation of sulphur dioxide in beer:

"Beer is an extremely complex mixture of more than 3,000 different compounds in an aqueous environment. Thus, it is perhaps not surprising that the maintenance of beer quality throughout its lifetime has been a considerable challenge for brewers. Whilst it is inevitable that chemical changes will occur in beer with the passage of time, it is the formation of flavor-active components which is of immediate concern to an overview of beer shelf life stability. Sulfur dioxide has long been recognized by brewers as the most important factor in delaying flavor staling, and prolonging the shelf life of beer. However, nowadays, sulfur dioxide and sulfites are considered allergens and concerns about the safety of their use as food additives have been on the increase. The present review is structured into three main parts. Firstly, the chemical properties of sulfur dioxide are presented, along with the toxic effects and maximum legal levels permitted according to U.S. and EU legislation. As the accurate determination of the free, bound and total sulfur dioxide in beer is essential to ensuring regulatory compliance, several methods have been developed for analyzing sulfur dioxide in beer. Thus, secondly, various types of methods are reported and compared with the officially recommended ones. Finally, the crucial role of sulfite in the control of flavor instability of beer is discussed in light of the current data. Two courses of action have been proposed, which are elucidated in detail relating firstly to the fact that sulfite inhibits beer oxidation during storage by acting as an antioxidant and, secondly, sulfite reacts with the carbonyl staling compounds in beer, and thereby masks stale flavors." - Luis F. Guido, University of Porto/Faculty of Science – Dept. of Chemistry and Biochemistry, Portugal

In the USA (and elsewhere) "contains sulphites" warning on the label is not required if less than 10ppm.

So, I guess you're correct when you say "it's almost as if commercial breweries know what they're doing"  

 

Edited October 23, 2019 by BlackSands

[BlackSands]

Just stumbled across a related Beersmith Podcast:

"...we don't want to want to go above 10, but we know if we get to say 6 or 7ppm sulphur dioxide it's better for shelf life than having 3 or 4. So, the higher you can go without going over the 10 the better it is in terms of flavour life..." -  Flavor Stability in Beer with Dr Charlie Bamforth

 

 

[Otto Von Blotto]

To be fair though, commercial beer often sits around a lot longer than home brew does before someone drinks it. 

In any case, I've personally never had any issues with beer going stale, so I've seen no point in doing anything differently to what I already do. 

[BlackSands]

2 hours ago, Otto Von Blotto said:

To be fair though, commercial beer often sits around a lot longer than home brew does before someone drinks it. 

In any case, I've personally never had any issues with beer going stale, so I've seen no point in doing anything differently to what I already do. 

Well, I don't think anyone was ever suggesting you should change what you do! 

Aside from the odd contaminant I don't think I've ever had a 'stale' beer as such (not sure what that tastes like mind you), but "hop fade" (linked to the presence of oxygen) is a very common complaint and one that bothers me and many others.  Minimising "hop-fade" and by implication reducing the presence of oxygen in the beer, was actually the main point of all this.  

 

And, according to Charlie....  apparently 110 days is the commercial target for beer stability. 

 

Edited October 23, 2019 by BlackSands

[Otto Von Blotto]

I'm not saying they were. I'm not sure if I've experienced hop fade either. I may have, or it just happens slowly enough that I don't really notice it. The kegs usually run out quicker than a batch of 65 stubbies used to though, once they go on tap they usually don't last more than a few weeks. I suppose drinking mostly at home these days has assisted in that... back in my bottling days I was usually at the pub every weekend and didn't drink much at home, so they'd last longer .

[BlackSands]

54 minutes ago, Otto Von Blotto said:

 I'm not sure if I've experienced hop fade either. I may have, or it just happens slowly enough that I don't really notice it.

I think you mentioned in the kegging thread that the kegs are chilled straight away.  Cold storage is something bottlers typically don't do.  I learnt from that Bamford podcast that cold storage is the #1 consideration when it comes to preserving beer freshness/flavour etc.  His advice was that brewers should invest in more fridges before considering doing anything else!  Of course there are practical considerations which make this option unreasonable for most.    

[Otto Von Blotto]

Sometimes they are, sometimes they sit at ambient for a few weeks or whatever before they go into the kegerator. The last pale ale did the latter, and didn't appear to lose anything over the time it lasted on tap, which admittedly wasn't that long. You could smell it from across the room when a beer was being poured.

I would love to keep my old kegerator for storing kegs but like you say it isn't practical. However, with two ferment fridges going, I'll probably be able to build a small stockpile and then I can use one of them to store kegs at different times when I don't need two batches fermenting. 

Edited October 23, 2019 by Otto Von Blotto

[BlackSands]

25 minutes ago, Otto Von Blotto said:

Sometimes they are, sometimes they sit at ambient for a few weeks or whatever before they go into the kegerator. The last pale ale did the latter, and didn't appear to lose anything over the time it lasted on tap, which admittedly wasn't that long. You could smell it from across the room when a beer was being poured.

I assume air was still purged though so headspace was full of CO2...