"Debugging" my oxidation incident

[deeve007]

Seems like my latest batch is oxidized, 3 days in fermenter and a sample tasted & smelled absolutely disgusting, not 100% sure what the "wet crdboard" taste is but I have the feeling this is probably it , leaving it for a few days just to see if anything changes...

So, putting my programmer head on I want to work out why it happened this time but not before, probably one of two changes I made to previous batches...

I've been doing split batches the past few brews due to the size of my pot, splitting everything in half, then mashing and boiling seperately, combining in fermenter.

Previous times I've done this over two days, first day using "no chill" and pouring wort straight into fermenter still hot, second day cooling wort down to pitching temps and adding, then pitching yeast. Has worked great for 3 brews.

This time I decided to do both in one longer day and then let the combined batch cool down overnight... so first batch did the same, second I cooled down a little and then added some whirlpool hops for 20 minutes, after this I added to fermenter and let both batches cool down overnight before pitching yeast. I also shook fermenter after pitching yeast to aerate, I hadn't done this before, had just sprinkled yeast on top and left it (and had worked fine).

So two main changes I can see where the issue may lie:
1) Because I cooled down wort a little to do whirlpool, but then didn't cool it down rapidly totally, this "warmish" wort may have been ripe for oxidation at the temperature it was.
2) Shaking fermenter to aerate yeast, though a brewer friend reckons it's unlikely this.

So would I be correct in thinking it's probably #1 that was the factor here?

 

[Kenmoron]

I don't think this is your traditional "wet cardboard" oxidation which is primarily oxidation of the BEER not WORT. Yeast need oxygen so you want plenty of it in there before you ferment (LODO brewers will have something to say about this, but I feel hot-side aeration shouldn't be something you worry about early on). Can you post a recipe? Is the beer still fermenting?

btw consensus is that the dried yeast you get in packets shouldn't require aeration...but I don't think it hurts.

 

[RPh_Guy]

Yeast need oxygen so you want plenty of it in there before you ferment (LODO brewers will have something to say about this

LODO brewers aerate/oxygenate the wort when pitching yeast.

 

[jjw5015]

I've never had a beer that tasted particularly good on day 3 of fermentation. I think you're a little early.

 

[verboten]

you are 3 days into fermentation. I wouldn't expect it to taste good

 

[micraftbeer]

I'm with your mindset of analyzing what's different in your process to figure out what went wrong. The thing to keep in mind is that there are other variables changing simply because it's going to be impossible to have a totally precision repeatable process at homebrew scale. So there are processes that are going to be inherently more susceptible to variation than others. So even if you didn't change your process, just due to variability of a process you can get different results batch to batch.

Based on this, here are some thoughts I have:

1. Doing a no chill batch is going to open your risk of contamination affecting your beer. There will be people with reports of how many times they've done this without an issue, but maybe they have a superb sanitation practice, and super air-tight container holding the wort while it cools down so there's no airborne stuff floating in and starting to grow before your yeast gets started. You will have less risk of contamination by getting your yeast pitched sooner. The shorter you make the time between end of boil and yeast pitch, the lower your risk of getting contamination. If you have to split your batch due to equipment size, you can still cool batch #1 and pitch half of your yeast, and then cool batch #2, add it, and pitch the other half of your yeast.

2. I have had issues with beers having a lot of dry hops developing oxidation flavors very quickly in the keg, which I have been able to eliminate by modifying my cold crash processes and keg filling practices to reduce oxygen exposure in these cases. So it could be a combination of a different recipe in this most recent batch versus your previous batches that made it more sensitive to oxygen intake in some of these other steps. Is your above results description with the exact same recipe, or different recipe?

3. You mentioned that you had this taste from the fermentor, not in the keg. So my above comments on oxygen intake during cold crash & kegging might not be relevant. But I will say that any taste I get in the fermentor I always take with a grain of salt. I've seen horrible tastes go completely away either with the very end of fermentation clean-up at the end (diacetyl rest), or just the first 2 weeks in a keg.

 

[bracconiere]

first day using "no chill" and pouring wort straight into fermenter still hot,

i still have a bad memory of doing that......

edit: and assuming you're using plastic and not glass. everyone here says plastic is O2 permeable i'd imagine hot wort would speed it up....

 

[deeve007]

i still have a bad memory of doing that......

edit: and assuming you're using plastic and not glass. everyone here says plastic is O2 permeable i'd imagine hot wort would speed it up....

As I wrote, doing it previously over 2 days, just the first wort hot, worked great.

 

[deeve007]

I will definitely be giving it until the end of the week and taste again, and maybe it will just be that I was very early tasting and it changes, it was just so horrible a taste it didn't seem normal.

Future brews I'm sticking with 10L until I get back home and can invest in a larger brew not/kettle, but I'm the kind of person that wants to understand as much as possible why something happened for future reference/adding to knowledge base. Appreciate all the input so far.

 

[bracconiere]

As I wrote, doing it previously over 2 days, just the first wort hot, worked great.

sorry...pouring hot wort in carboys still gives me chills....

 

[deeve007]

If you have to split your batch due to equipment size, you can still cool batch #1 and pitch half of your yeast, and then cool batch #2, add it, and pitch the other half of your yeast.

Ahh, good suggestion if that works fine if I do another split batch!

 

[deeve007]

sorry...

All good, any suggestion helps, gets me thinking .

 

[bracconiere]

All good, any suggestion helps, gets me thinking .

 

[deeve007]

sorry...pouring hot wort in carboys still gives me chills....

No chill method works great for many Australians and I have been overly anal about sanitation every time.

(and I know a cube would be better than fermenter but loads of reports of brewers doing the latter fine, I don't think that's the issue, at least doing it with one wort batch)

 

[Kenmoron]

LODO brewers aerate/oxygenate the wort when pitching yeast.

I know they still oxygenate pre-pitch... the full sentence being "LODO brewers will have something to say about this, but I feel hot-side aeration shouldn't be something you worry about early on."

 

[eric19312]

I think you should pitch the yeast as soon as the first part of the batch reaches pitching temperature. I'd force chill it and get it started on day 1. If timing forces you to use no chill it then I think you need a container that just holds it with near zero headspace. The cubes and jerry cans the australians use make a lot of sense. If you consider their process they take very hot wort which would have little or no oxygen and get that into an airtight container with no headspace while it is still hot. The heat from the wort assures sanitization (sure go ahead and worry about botulism but haven't heard of any no chill brewer getting sick from botulism yet) and wort doesn't start to absorb oxygen until it chills. And their wort is protected from oxygen by the package.

Also...The LODO brewers do oxygenate their wort...after the yeast is pitched.

For your second half of the ferment you can either make it next day and force chill or no chill again and add it a day later. Again you don't want this part of the ferment to pick up any oxygen after boil and want to minimize oxygen exposure to the ferment when you add it in.

 

[deeve007]

I think you should pitch the yeast as soon as the first part of the batch reaches pitching temperature. I'd force chill it and get it started on day 1. If timing forces you to use no chill it then I think you need a container that just holds it with near zero headspace. The cubes and jerry cans the australians use make a lot of sense. If you consider their process they take very hot wort which would have little or no oxygen and get that into an airtight container with no headspace while it is still hot. The heat from the wort assures sanitization (sure go ahead and worry about botulism but haven't heard of any no chill brewer getting sick from botulism yet) and wort doesn't start to absorb oxygen until it chills. And their wort is protected from oxygen by the package.

I obviously take your point, but as I wrote before when putting just the first wort into the fermenter hot there was zero issues, and from reading online others doing no chill in a fermenter (there's quite a few) they believe the heat/steam from the hot wort would kill anything of issue (fermenter obviously sanitized beforehand).

I'm more inclined to believe it's putting the luke warm second wort in where the issue may have arisen from (where I cooled down the second wort previously), as I've read that's the "danger" time for wort, and hence why you need to cool it down to pitching temps rapidly. I would obviously need to repeat and do side-by-sides to know for sure, and of course there's always the chance I just haven't perfected any of my other process steps too.

 

[eric19312]

The "danger" time/temp has to do with contamination not oxidation. This is the temperature below which heat will kill contaminating organisms - about 130F. Once you drop below this point you risk a contaminating bacterial or wild yeast taking hold. If they are in there. No chill works because you kill off all the organisms with heat while the container is sealed. No organisms, no contamination no matter how long in the "danger zone". Maybe. Again the no chill guys get it to work fine.

Oxidation is a different issue/mechanism.

 

[deeve007]

Ahh okay, thanks for that clarification, appreciated.

(and I am presuming it's oxidation causing the horrible taste/smell, I'm new to this and contamination, I may know more leaving it for a few more days and seeing what eventuates... like a school science experiment )

 

[jjw5015]

it's highly unlikely you're experiencing oxidation off flavors after only 3 days. I think you're experiencing 3 day old beer off flavors. Give it time.

 

[deeve007]

it's highly unlikely you're experiencing oxidation off flavors after only 3 days. I think you're experiencing 3 day old beer off flavors. Give it time.

If it is this (and obviously fingers crossed) it's by an extreme amount the most horrendously tasting 3 day old beer I've ever sampled from a fermenter in my short brewing experience!!

 

[MaxStout]

If it is this (and obviously fingers crossed) it's by an extreme amount the most horrendously tasting 3 day old beer I've ever sampled from a fermenter in my short brewing experience!!

I've made the mistake of tasting a few of my beers early on in fermentation out of curiosity, and let's just say it was...memorable. Never judge your beer by its flavor that early. Yeast are good about cleaning up after themselves at the end of fermentation. No worries, it'll be much better later on.

 

[bracconiere]

If it is this (and obviously fingers crossed) it's by an extreme amount the most horrendously tasting 3 day old beer I've ever sampled from a fermenter in my short brewing experience!!

i thought o2 just ruined hop flavor? maybe make it darker a bit.....nothing horrendous......

 

[deeve007]

i thought o2 just ruined hop flavor? maybe make it darker a bit.....nothing horrendous......

"Wet cardboard" was the most common descriptor I'd read/heard, no?

 

[DVCNick]

At only three days you probably still want it to be oxidized to help the yeast? As others have said... I wouldn't be tasting it that early and expecting to get any viable information.

This past weekend I tasted the post-boil OG sample for the first time just out of curiosity. As expected, it just tasted like flat sugar water... gross. Add in some early-fermentation yeast byproducts and I'm sure that disgusting is closer to the norm than the aberration.

 

[deeve007]

This past weekend I tasted the post-boil OG sample for the first time just out of curiosity. As expected, it just tasted like flat sugar water... gross. Add in some early-fermentation yeast byproducts and I'm sure that disgusting is closer to the norm than the aberration.

The 5 previous brews I've done I've always had a tiny taste both after boil (once cooled) and after a few days in fermeter (impatience ) and it's never tasted super horrible. This basically has me needing to wash my mouth out or risk throwing up...

Anyway, we'll see what it's like after a week, when I'm due to throw in some more dry hops... obviously don't want to waste more hops if it's not at least giving an indiction of being on its way to a drinkable beer...

 

[bracconiere]

This basically has me needing to wash my mouth out or risk throwing up...

sounds worse then wet cardboard.....

you said you only added whirlpool hops to the second half? maybe something there.....?

 

[deeve007]

I've never tasted wet cardboard so I have no idea...

 

[bracconiere]

I've never tasted wet cardboard so I have no idea...

it's not as bad as chewing tobacco....

 

[micraftbeer]

Anyway, we'll see what it's like after a week, when I'm due to throw in some more dry hops... obviously don't want to waste more hops if it's not at least giving an indiction of being on its way to a drinkable beer...

Don't pull the plug. Let it finish fermenting, add your dry hops, then let it condition in keg/bottles. After 2 weeks it tastes gross, dump it. But dumping it before it's done is a mistake. You won't really know if the dry hops are a waste or not until after it completely finishes and then conditions for about 2 weeks in keg/bottle. Don't throw away all the hours of time you have invested so far.

But if you get to the end and it tastes nasty, no point putting yourself through that at that point.

 

[Jako]

Seems like my latest batch is oxidized, 3 days in fermenter and a sample tasted & smelled absolutely disgusting, not 100% sure what the "wet crdboard" taste is but I have the feeling this is probably it , leaving it for a few days just to see if anything changes...

So, putting my programmer head on I want to work out why it happened this time but not before, probably one of two changes I made to previous batches...

I've been doing split batches the past few brews due to the size of my pot, splitting everything in half, then mashing and boiling seperately, combining in fermenter.

Previous times I've done this over two days, first day using "no chill" and pouring wort straight into fermenter still hot, second day cooling wort down to pitching temps and adding, then pitching yeast. Has worked great for 3 brews.

This time I decided to do both in one longer day and then let the combined batch cool down overnight... so first batch did the same, second I cooled down a little and then added some whirlpool hops for 20 minutes, after this I added to fermenter and let both batches cool down overnight before pitching yeast. I also shook fermenter after pitching yeast to aerate, I hadn't done this before, had just sprinkled yeast on top and left it (and had worked fine).

So two main changes I can see where the issue may lie:
1) Because I cooled down wort a little to do whirlpool, but then didn't cool it down rapidly totally, this "warmish" wort may have been ripe for oxidation at the temperature it was.
2) Shaking fermenter to aerate yeast, though a brewer friend reckons it's unlikely this.

So would I be correct in thinking it's probably #1 that was the factor here?

For me pulling a sample would be the start of the oxidation. over the past two years i find myself waiting longer and longer to pull a beer from a fermenter and i don't sample untill its finished in the keg or if you bottle after at least 2 weeks in a bottle.

The only time i had beers taste absolutely awful right from the start are beers that had a infection. i had a infection that lasted 4 beers once i almost quit brewing because it set me back so much. But from i remember it smelled like "old building" and it tasted like it also.

 

[deeve007]

Well whether it was oxidation, infection, or something else, after 11 days in the fermenter with no improvement time to admit defeat on this one. I even bottled one a few days ago, to see if carbonation would change things at all, but turned out just as disgusting as in the fermenter...

Maybe in the future I'll learn I didn't wait long enough, but it was just too disgusting for me to believe it could come right with a couple more weeks in fermenter/bottle, and way darker and cloudier than it should have been with the grain bill utilised...

 

[Jako]

Looks like yeast still in suspension. You could be right might be wild yeast just eating everything up.

 

[seatazzz]

Three days in, no wonder it tasted horrible to you. The yeast are still working, and they can throw off some nasty-ass flavors in the beginning, sulfur being one of them (stick an old-fashioned match head in your mouth, bout like that). Primary fermentation can take up to 7 days depending on recipe, yeast, temperature, phase of the moon, what have you; during that time the yeast are having a huge party and making a mess. After primary is finished, give them more time to clean up their mess before the parentals (read: you) come home and see what they did. The first few days of fermentation they are eating all the simple sugars they can find, and pissing alcohol and farting co2; once the easily broken down sugars are gone, they start breaking down the by-products of fermentation, basically cleaning up. This is when you will notice little or no activity in the airlock, which DOES NOT mean it is done. Give it some more time.

Will note here as well; DON'T OPEN THE FERMENTER SO MUCH. Doing so risks letting oxygen, or even worse, stray wild yeast or nasty bacteria, in to set up shop and kick your good yeast to the floor and take over. Yeast are ancient organisms and know what they're doing; let them get on with it.

 

[deeve007]

I opened the fermenter once to dry hop. I've made previous beers with a similar grain/hops profile and nothing even remotely like the "off" taste and smell this time, which one of these days I'm sure I'll have the brewing vocabulary to describe properly. Nor anything close to the colour that resulted, far darker than the grain profile would suggest

As I wrote above, pretty certain the issue is around the only things I did different from the past brews when nothing went wrong, which I'll determine for sure over my next few brews.

 

[IslandLizard]

How are you transferring the wort from the kettle to your fermenter? Using a strainer?

Is there a valve or something on your brew kettle? They can get gross on the inside providing infections to every ounce of wort passing by or through, for years to come. Same for fermenters with spigots.

 

[deeve007]

No valve on brew kettle, and have been super-anal with cleaning and sterilizing at all times.

I'm doing a cheaper recipe this time round, but back to the exact process I was using before this latest batch to see if that removes the issue I had. If it does I'll know where it likely came from, if not exactly what it was. If it doesn't then it may mean I need to get a new fermenter perhaps, that's still smelling a little funky after an initial clean of this dumped batch, I'm leaving it soaking overnight in a bleach solution to clean it as well as possible.

Anyway, as a newbie things were proceeding too smoothly almost, so another part of the learning curve all this...

 

[IslandLizard]

We don't (can't) sterilize much, if anything, in brewing; sanitizing is as good as it gets. Be thorough with both cleaning and sanitizing!

It's not uncommon for homebrewers starting to get infected beers after a few successful runs. Usually something got missed in the cleaning/sanitizing processes. So check around and look for those missed or forgotten areas. Spigots and transfer hoses can cause havoc.

You can't sanitize something that isn't clean to start with. Biofilm can start to build up quicker in more hidden and less accessible areas. Alkaline cleaners in combination with scrubbing will help to remove them. Bleach is not a cleaner, it's a sanitizer.

Wort between 60 and 130F is super prone to infections.

If you combine batches over 2 days, pitch half the yeast in #1 as soon as it has come to pitching temps. Chill #2 in a different fermenter while #1 is fermenting. As soon as #2 has come to pitching temps, pitch the other half in that.
Pitching enough cells (use a yeast calculator) and/or active (vitality) starters guarantees fast lift off. Good wort aeration at pitching time helps yeast to establish herself by faster growth, which deters anything else from getting a foothold.

You may be able to add the chilled wort from #2 to #1 after one day, but I'm not sure if that's the best strategy.
Adding wort to an established fermentation or at the trail end is fine, but during the lag phase may not be. pH, cell density, and stuff.

Brewing 2 half batches back to back should not take all that much more time as brewing one. You can mash (and lauter) #2 while #1 boils. One prep and one cleanup.

After a few days once they're both established, you could combine the contents of the fermenters if you want, but avoid air uptake, splashing, etc.!

 

[deeve007]

I'm going to be doing 10L batches for the moment, as something in the splitting process was probably the issue, and while it wouldn't be that hard to improve the process as you've outlined, I want to make smaller and more frequent batches anyway, now that I'll be using custom recipes rather than the limited available kits where I am (all 20L kits, just a couple very simple 10L ones).

Also means I can get back to focusing on perfecting the core processes I need to, rather than adding in additional processes around splitting the batch.

 

[IslandLizard]

Good idea! ^

What kind of cleaners are you using? You need to clean those infected fermenters thoroughly. Then bleach bomb them, and/or leave out in direct sunlight for UV sanitation.

What kind of yeast are you using?