Oxidation Blues

[Pataka]

It seems I was destined for some bad fate after my first three batches all turned out superb, even after what felt like a near miss with my third. My third, fourth, and perhaps even fifth all have what I'm fairly sure is oxidation.

Batches 1 and 2 were based on Coopers Real Ale, using the standard kit yeast. They were scaled down recipes so I could make one gallon batches, and bottled using my wine racking hose and racking cane. No bottle wand in sight. My third was Mangrove Jacks' Dark Best Bitter, made in my 5 gallon fermenter using the standard Burton Union Ale yeast that comes with the kit, bottled using the bottling wand. All three had little had no noticeable oxidation whatsoever.

My fourth batch was a Mangrove Jacks Pale Ale kit, made using the standard kit yeast, in my 5 gallon fermenter, bottled using the bottling wand. The fifth was a SMASH ale made using DME and Waimea hops, and using yeast I had harvested from the Mangrove Jacks Pale Ale and made into a starter, bottled using the wine racking equipment, just like the first two batches.

Both these two have a strong smell and aftertaste of 'something' but I couldn't pinpoint it initially. People say oxidation is a 'cardboardy' flavour. I couldn't recall that smell/taste. Then a few weeks back I was shopping in a bulk-buy supermarket with lots of cardboard boxes in one part, and thought to myself "hey, that smells like my beer tastes". It isn't mellowing as the beer ages either. I know some people say that oxidised beer gets worse as the beer ages, so you need to drink the batch fast. I can't do that. It simply isn't a nice taste, so drinking it at all isn't really something I'd enjoy. Why do it faster?

Naturally, I'm trying to work out where I'm going wrong. There have been three successful batches, made using Coopers standard yeast and Burton Union yeast. Two were bottled using a racking hose, one via a bottling wand.

There have been two unsuccessful batches, made using Mangrove Jacks standard yeast, each being bottled via methods already used successfully.

In terms of the bottles, the SMASH kit used bottles I had used previously (and sanitised, obviously) while the Pale Ale used new PET bottles, but a brand I had used before.

So far, the only variable that appears to have anything to do with it is the yeast. My sixth batch (a double-strength Coopers Real Ale) used the same yeast, but hasn't finished carbonating yet so I haven't tried it. If the yeast has any say in this, there's a good chance this batch will be cardboard as well.

Is it that certain yeasts are more sensitive to oxygen during bottling than others? What else could it be?

I've read that oxidation doesn't usually make itself known until later in the process. That being the case, I shouldn't be having it this early, so perhaps it's not oxidation but something else...

 

[joshesmusica]

what were your ferment temps like?
were you just following kit instructions as far as ferment times, or did you do gravity readings in order to ensure complete fermentation? just wondering if you tasted it throughout the process. one of the reasons i do multiple gravity readings during fermentation is so that i can taste it to see how it's going. before i bump up the temps, test. before dry hop, test. before bottling, test. if i ever develop off-flavors, i can always go back to a certain point during the ferment that they developed. that has helped me, on one brew that i had off-flavors, determine what went wrong.
i wouldn't personally rule out oxidation, because i don't know what it tastes like, or the science behind it. i just know that from my own anecdotal experience, i've splashed a lot of beers when racking and bottling before i learned about the effects of oxidation. i've never had a beer that tasted like cardboard. but then again, my beers aren't usually around long enough for those flavors to take over. so if your beers aren't very old, i would be surprised if the oxygen has ruined it so early, as i've read it takes at least a couple months for that to happen.
my first thought was actually old kit ingredients. my second thought was ferment temps and that maybe the flavor is actually some esters or phenols that you don't like.

 

[Pataka]

what were your ferment temps like?
were you just following kit instructions as far as ferment times, or did you do gravity readings in order to ensure complete fermentation? just wondering if you tasted it throughout the process. one of the reasons i do multiple gravity readings during fermentation is so that i can taste it to see how it's going. before i bump up the temps, test. before dry hop, test. before bottling, test. if i ever develop off-flavors, i can always go back to a certain point during the ferment that they developed. that has helped me, on one brew that i had off-flavors, determine what went wrong.
i wouldn't personally rule out oxidation, because i don't know what it tastes like, or the science behind it. i just know that from my own anecdotal experience, i've splashed a lot of beers when racking and bottling before i learned about the effects of oxidation. i've never had a beer that tasted like cardboard. but then again, my beers aren't usually around long enough for those flavors to take over. so if your beers aren't very old, i would be surprised if the oxygen has ruined it so early, as i've read it takes at least a couple months for that to happen.
my first thought was actually old kit ingredients. my second thought was ferment temps and that maybe the flavor is actually some esters or phenols that you don't like.

Ferment temps were actually pretty decent. Somewhere between 20 and 22 most the time. The Dark Best Bitter I made (that tastes brilliant) had a lot more issues, as it brewed over the peak of summer, where we had some days of over 30 (celsius obviously). The first two batches were made in spring, and the temps would have been the same as the two with the unpleasant taste.

Old ingredients wouldn't explain how the Mangrove Jacks Pale Ale was affected, as it was brand new.

I certainly like your idea of tasting at various stages along the way, and with a fermenter with a spigot that's most definitely possible.

At the moment, I have two possibilities. Either that yeast creates, or makes it easier to unwantingly end up with, some flavours that really don't appeal to my pallet; or the Pale Ale perhaps had an infection of some sort, and because that was the seed batch for the yeast starter I used in the SMASH ale, it was simply transferred on. Tonight I'll try one of the double strength Real Ale bottles, which were also fermented using yeast from the same source. If that has the same characteristic, then it probably narrows it down to one of those two.

 

[joshesmusica]

Ferment temps were actually pretty decent. Somewhere between 20 and 22 most the time. The Dark Best Bitter I made (that tastes brilliant) had a lot more issues, as it brewed over the peak of summer, where we had some days of over 30 (celsius obviously). The first two batches were made in spring, and the temps would have been the same as the two with the unpleasant taste.

Old ingredients wouldn't explain how the Mangrove Jacks Pale Ale was affected, as it was brand new.

I certainly like your idea of tasting at various stages along the way, and with a fermenter with a spigot that's most definitely possible.

At the moment, I have two possibilities. Either that yeast creates, or makes it easier to unwantingly end up with, some flavours that really don't appeal to my pallet; or the Pale Ale perhaps had an infection of some sort, and because that was the seed batch for the yeast starter I used in the SMASH ale, it was simply transferred on. Tonight I'll try one of the double strength Real Ale bottles, which were also fermented using yeast from the same source. If that has the same characteristic, then it probably narrows it down to one of those two.

so is that 20 and 22 ambient, or temp of the beer? i try to keep my thermometer reading on my bucket at about 18 or 19. ambients around 16 or 17. if 20-22 is your ambient temp, your actual temps in the fermenter could be 25 or higher, which is gonna produce off flavors. if your temps were above 30 definitely off flavors, and if the ambient temps were 30, you're basically begging for tons of fusel alcohols.

i would say at the lower temps the flavor is probably some esters from the yeast that you're not liking. at temps above 30 the off flavors are probably from fusels. so my first suggestion is to get those temps down.

since you mentioned the mangrove jack's kit, then that's why my second thought came into play. i don't think it's old ingredients, necessarily.

as far as sampling each i don't think you should be using the spigot, it's likely too close to the yeast cake, and probably has tons of yeast resting inside of it. at least on my fermenting buckets it's like that.

i really don't think it's an infection.

 

[okbecker]

Were these extract Kits? What is your chilling process ? Do you add tap water after boil to top up or chill with, oxygen from the tap water can lead to oxidation issues ? Do you use a secondary, if so what size and what is fill volume. To much head space can lead to oxidation issues ? What temp do you bottle condition your beers at?

Generally oxidation faults are more of a process issue than yeast or ingredient...provided your extract or grain is not stale and you are certain of the fault.

 

[m1batt1]

Were these extract Kits? What is your chilling process ? Do you add tap water after boil to top up or chill with, oxygen from the tap water can lead to oxidation issues ?

I have to disagree with you on this particular point. Everything I've read suggests after the boil that you need oxygen in your wort for the yeast to take off properly. After fermentation is when introducing oxygen is a problem.

 

[LLBeanJ]

Everything I've read suggests after the boil that you need oxygen in your wort for the yeast to take off properly. After fermentation is when introducing oxygen is a problem.

This is correct.

 

[okbecker]

Good catch on the water prior to ferment, actually its top up water used after primary ferment or with sugar when bottling... my error! Though HSA could lead to same flavors as he's describing...I know HSA is highly debatable..lol

 

[kev211]

Were these extract Kits? What is your chilling process ? Do you add tap water after boil to top up or chill with, oxygen from the tap water can lead to oxidation issues ?

Oxygen is very important prior to fermentation. Thats why we shake the carboy, use an oxygen stone or other methods of making oxygen present in the wort.

Edit: looks like you cleared up your statement. Nevermind...

To the OP, what are your bottling methods (besides the hose and wand)? What kind of bottles, bottle caps and bottle capper do you use? When I bottled, I had some oxygenation issues and noticed that some of my caps werent seating properly. Also, I think that in general when bottling its inevitable that beer is in contact with air a lot more (whether or not this can cause oxygenation is up to you, and no; this is not a "you should switch to kegging because its better statement" haha)

 

[Pataka]

I don't use a secondary. I always just leave it in primary with the blanket of CO2 while it clears, then bottle.

The temps I was referring to were ambient temps, not fermentation temps. The fermentation temps are generally more conservative, as while it hit 30 degrees over summer, it wasn't for long enough to bring the wort up to anywhere near that (thank heaven). The thing is though, the temps were worst when fermenting one beer that came out fine. However, the 'problem' yeast is a different strain, so maybe it is more temperature sensitive.

I use PET bottles with plastic caps. I did have one where the seal failed completely, which I spotted after about 6 weeks as it was the only bottle in the batch that was totally flat.

I've tried one of the Real Ale double strength brews made from the same yeast, and it has the familiar taste. It's by no means as strong, but it's definitely there. So either it's that the yeast itself isn't to my taste, or the yeast wants different fermentation temps from what I've been giving it. The Real Ale was the last batch to ferment, so will have had cooler temps. It's also the one where the unwanted flavour is the weakest. So it's pointing more and more to the latter.

I future, I intend to start buying yeast separately, rather than using the yeast that comes with the kits. Hopefully that will help.

 

[Queequeg]

Its the pet bottles. You can only use the lids about two or three times. Even if the seem to tighten and keep the CO2 in they will let O2 in.

I had a wheat beer that I bottled part in pet and part glass. All the pet tasted like card (stale) at first and sherry later. All the g
lass were fresh and crisp still at 6 months.

Either buy new screw caps or better still Switch to crown caps/glass

 

[joshesmusica]

I don't use a secondary. I always just leave it in primary with the blanket of CO2 while it clears, then bottle.

this is kinda a myth. co2 doesn't just sit there like a blanket once you open the lid. a little bit maybe, but the minute you walk by it or wave your hand around near it or basically get air moving around it, it will combine with the air eventually.

The temps I was referring to were ambient temps, not fermentation temps. The fermentation temps are generally more conservative, as while it hit 30 degrees over summer, it wasn't for long enough to bring the wort up to anywhere near that (thank heaven). The thing is though, the temps were worst when fermenting one beer that came out fine. However, the 'problem' yeast is a different strain, so maybe it is more temperature sensitive.

how do you know the temperature of the fermenting beer was lower than ambient temps? and how exactly is that possible? haha when i'm talking ambient temps, i'm talking ambient in the room where it's fermenting, not outside the house temps. what strain of yeast was it? that can also be true. for example i hear, although i've never tested it, that us-05 (or any of it's liquid equivalents) can handle temps pretty well. and of course there are the hefe strains and the saison strains that prefer it a bit warmer. but even those need some control.

I've tried one of the Real Ale double strength brews made from the same yeast, and it has the familiar taste. It's by no means as strong, but it's definitely there. So either it's that the yeast itself isn't to my taste, or the yeast wants different fermentation temps from what I've been giving it. The Real Ale was the last batch to ferment, so will have had cooler temps. It's also the one where the unwanted flavour is the weakest. So it's pointing more and more to the latter.

I future, I intend to start buying yeast separately, rather than using the yeast that comes with the kits. Hopefully that will help.

i personally never buy kits. i purchased beersmith, and get recipe ideas from here and friends that brew, and go purchase what i want. this way i also know it's fairly fresh, but also because then i get to choose specific yeast strains.

i would highly recommend finding somebody else to try your beer. you're pretty biased right now. once something like that gets in your head, it actually is very hard to not taste it. for example, i had some brews that to me tasted a bit bubble gummy. the only thing they had in common was that i added sugar to them. i had friends, and my wife (who's no expert, but has definitely tried tons of homebrew from myself and her step-dad), try these beers and even when i mentioned the fact that they had a bubble-gum flavor to me, they didn't taste it. sometimes we confirm our biases because our brain will actually trick us into tasting something, or in other words confirmation bias.

here's a guy that does tons of experiments that are pretty well respected in the homebrew community, and he does a test on perception. the results are incredible! and have always made me think twice about my own perceptions of my own homebrew (of which i am typically expecting something to be off).
http://brulosophy.com/2014/11/03/the-impact-of-expectation-on-perception-exbeeriment-results/

 

[Pataka]

Its the pet bottles. You can only use the lids about two or three times. Even if the seem to tighten and keep the CO2 in they will let O2 in.

I was thinking you possibly had it nailed as some of the bottles are on their third use now. Except then I remembered the Pale Ale was bottled in brand new PET bottles with brand new lids.

 

[Pataka]

this is kinda a myth. co2 doesn't just sit there like a blanket once you open the lid. a little bit maybe, but the minute you walk by it or wave your hand around near it or basically get air moving around it, it will combine with the air eventually.

I know what you mean. CO2 and O2 aren't like oil and water. They do actually mix when they get together. But when I have my brew sitting in primary I don't take the lid off once fermentation is slowing, and leave the airlock in place too.

how do you know the temperature of the fermenting beer was lower than ambient temps?

I was referring to the outside temps, not ambient temps in the room.

i personally never buy kits. i purchased beersmith, and get recipe ideas from here and friends that brew, and go purchase what i want. this way i also know it's fairly fresh, but also because then i get to choose specific yeast strains.

Eventually, I will go the same way. My issue at the moment is I've got no way of boiling ~5 gallons of anything, plus I figure while I'm still cutting my teeth and figuring out what I'm doing, it's probably best to stick with kits as they are less expensive mistakes if I have to dump a batch for any reason.

i would highly recommend finding somebody else to try your beer. you're pretty biased right now. once something like that gets in your head, it actually is very hard to not taste it. for example, i had some brews that to me tasted a bit bubble gummy. the only thing they had in common was that i added sugar to them. i had friends, and my wife (who's no expert, but has definitely tried tons of homebrew from myself and her step-dad), try these beers and even when i mentioned the fact that they had a bubble-gum flavor to me, they didn't taste it. sometimes we confirm our biases because our brain will actually trick us into tasting something, or in other words confirmation bias.

I know all about perception and confirmation bias from my audiophile days. It's a good idea to bring a third party into this.

 

[joshesmusica]

I was referring to the outside temps, not ambient temps in the room.

Eventually, I will go the same way. My issue at the moment is I've got no way of boiling ~5 gallons of anything, plus I figure while I'm still cutting my teeth and figuring out what I'm doing, it's probably best to stick with kits as they are less expensive mistakes if I have to dump a batch for any reason.

so what are the temps in the room you're fermenting? that's what really matters to help determine if they're too high.

i do extract still. i just build my own extract kit. basically i start with a pale or a pilsner extract base. and then steep some specialty grains to give it the color and flavor profile i'm looking for. then typically go with a dry yeast of some sort. although some will say doing a full boil with extract will help improve it some, the best things you can do for your beer are sanitation, pitching proper amount of healthy yeast, and temperature control during fermentation.
so i usually boil 12-16 liters in my 19L pot, then i top off to 25L. so if you design the recipe to be 1.055 OG at 19L and you are getting your fermentables from something that is pretty set in stone like extract or sugar, then you just boil the same as usual, then top off to 19L and you know you'll be spot on the OG listed in beersmith.
not to mention that let's say you have 15L at 1.092, and you were wanting 25L of 1.055. then you just go to the Dilution Tool that is in the software already, and it will tell you what happens if you top off 15L at 1.092 with 10 more liters of water. Which just so happens to be 25L of 1.055. This helps you determine what your OG is since after you dilute it, it's hard to get a properly mixed reading.
it's really not difficult to use, and super easy to build a recipe. for example an ipa can just have pale malt extract (which most of the time already has a bit of carapils or something in it), then just type in what hops you want to add, and when, then you customize how much abv you want and how much bitterness you want, so you get to make beer that suits your flavor profile best.

 

[Queequeg]

I still think its the bottles. The problem is ensuring a consistent seal even with new seals. Those seals that have been used three times will definitely result in oxidation. My advice is do a batch with glass bottles and crown caps.

 

[Pataka]

I like coming back to my threads as I learn new stuff about them. I tried another one of the beers I thought was oxidised today, a week after I last tried one, and the unpleasant taste seems to have subsided. I now think it's just some unwanted esters produced by that particular strain of yeast, or poor temperature control for that strain of yeast.

The reason I say this is that, the SMASH ale I made had the same taste before I even bottled it (I forgot that when I first posted) which really should rule out oxidation and/or the bottles as the source of the problem. If it's fading, I can live with that.

The moral of this story is the same as for my last concerned post and that is, if in doubt... leave it alone in the bottles.

 

[Queequeg]

When you taste a beer that is oxidised there is no doubt in your mind.

I often find us_05 has a flavour "off" flavour when young.