Saison - pellicle or yeast rafts?

[Mook]

To be honest, this isn’t the first time I’ve been worried about an infection, but this might be the one that actually is.

Saison fermented with WLP565, “open” fermentation with a piece of foil covering the grommet on my bucket lid, as suggested by Drew Beecham for this particular yeast strain to avoid the stall. Left for 3 weeks, ended at 1.007, cold crashed for 24 hours. Used an 8 gallon bucket for a 5 gallon batch because that was all I had on hand at the time. Replaced the foil with an airlock before cold crashing.

I went to keg yesterday and noticed more “stuff” than usual floating on the surface. Typically I’ll see some hop residue, maybe even a thin film that I attribute to hop oils, and a few clear bubbles. This time, there’s a bit more going on. First time using this yeast, and it seems that saisons are maybe more prone to yeast rafts?

However there are one or two spots that have white-ish bubbles, which are my main concern. I kegged anyway, avoiding the white bubbles. Sample tasted tart, but it’s an uncarbed saison at this point so it’s hard to say if it’s normal or not, but it didn’t taste “bad.”

I’m going to drink it but wondering what you guys think, if I should change my process at all next time, ditch the bucket, etc. Thoughts?

 

[brownni5]

Hard to tell from the photos.

If it is a pellicle, off flavors take a while to develop, especially if it's kegged and cold, so your beer is likely ok. Might want to check out the Pellicle photo coll collection thread in the Lambic and Wild beer forum to compare.

 

[TwistedGray]

You need better photos, but I think it's just yeast. With a pellicle you will get much larger bubbles than what is showing. Give it time to see if any changes develop, but pretty sure it's yeast.

 

[Mook]

You need better photos, but I think it's just yeast. With a pellicle you will get much larger bubbles than what is showing. Give it time to see if any changes develop, but pretty sure it's yeast.

Sorry for bad pics, here is a closeup of the troubling bubbles.

I did a fair bit of googling and found nothing that quite looks like this. Agree that pellicles look much more developed, but other yeast raft pictures look much more benign than mine...

 

[Miraculix]

That clearly is a pellicle, plus some yeast rafts. If you're lucky, the beer might be ok young but quickly get worse with time. You might find out that the beer has zero foam stability and that the general flavour is not as expected.

I dealt with exactly the same look multiple times and found out that it most certainly is because of oxygen exposure.

The beer won't be completely ruined but it will be way beyond what it could have been. I guess your bucket is not tight enough (mine wasn't...). One trick is to bottle as soon as possible, so that there is not much time for the bacteria to develop, but you need to have some experience so that you don't create bottle bombs by bottling too early.

 

[brownni5]

That clearly is a pellicle, plus some yeast rafts. If you're lucky, the beer might be ok young but quickly get worse with time. You might find out that the beer has zero foam stability and that the general flavour is not as expected.

I dealt with exactly the same look multiple times and found out that it most certainly is because of oxygen exposure.

The beer won't be completely ruined but it will be way beyond what it could have been. I guess your bucket is not tight enough (mine wasn't...). One trick is to bottle as soon as possible, so that there is not much time for the bacteria to develop, but you need to have some experience so that you don't create bottle bombs by bottling too early.

Some mis-information here, and as someone who strives for pellicle production (ok, maybe not, but I do a lot of mixed ferments), I feel it necessary to dispell them.

1. As stated above, I don't see a remarkable pellicle, but neither do I see evidence to the contrary.

2. Pellicles are caused by exposure to oxygen in the presence of possibly wild yeast or bacteria. Oxygen exposure itself does not cause infections by either yeast or bacteria.

3. Infections can lead to over-attenuation if wild yeast is present. If only bacteria is present, then it will not attenuate further, at least not significantly so. Generally, pellicles are attributed to wild yeast, but bacteria can form them (we think), so there's really no way to know what is responsible for any one pellicle. Further, many wild yeast are alcohol-intolerant, crapping out around 5% ABV or lower. When we find one that isn't, we get excited!

4. An infection will not necessarily lead to bad flavor or reduced head-retention. All depends on what infected the beer/wort. Too much acid production can ruin head retention, but wild yeasts typically don't produce much acid. Bacteria (Acetobacter, Lactobacillus, and Pediociccus) are the big bacteria producers. In the presence of hops, these bacteria generally take a long time (months/years) to produce noticable acid. Acetobacter is the "worst" of these - it's the bacteria responsible for making vinegar. Nobody wants 5 gallons of malt vinegar on tap.

How soon after pitching did you notice this? Had you opened the bucket lid a bunch after primary was done? Very little is understood about pellicles, but they generally take a little while after the introduction of oxygen to develop.

 

[Mook]

Some mis-information here, and as someone who strives for pellicle production (ok, maybe not, but I do a lot of mixed ferments), I feel it necessary to dispell them.

1. As stated above, I don't see a remarkable pellicle, but neither do I see evidence to the contrary.

2. Pellicles are caused by exposure to oxygen in the presence of possibly wild yeast or bacteria. Oxygen exposure itself does not cause infections by either yeast or bacteria.

3. Infections can lead to over-attenuation if wild yeast is present. If only bacteria is present, then it will not attenuate further, at least not significantly so. Generally, pellicles are attributed to wild yeast, but bacteria can form them (we think), so there's really no way to know what is responsible for any one pellicle. Further, many wild yeast are alcohol-intolerant, crapping out around 5% ABV or lower. When we find one that isn't, we get excited!

4. An infection will not necessarily lead to bad flavor or reduced head-retention. All depends on what infected the beer/wort. Too much acid production can ruin head retention, but wild yeasts typically don't produce much acid. Bacteria (Acetobacter, Lactobacillus, and Pediociccus) are the big bacteria producers. In the presence of hops, these bacteria generally take a long time (months/years) to produce noticable acid. Acetobacter is the "worst" of these - it's the bacteria responsible for making vinegar. Nobody wants 5 gallons of malt vinegar on tap.

How soon after pitching did you notice this? Had you opened the bucket lid a bunch after primary was done? Very little is understood about pellicles, but they generally take a little while after the introduction of oxygen to develop.

Thanks for the detailed write up!

I pitched 3.5 weeks ago, fermented at 65 for 4 days, let free rise to room temp (70) for a week, then slowly ramped to 80 using a heat wrap and left for another week or so. During the entire process, I left the sanitized foil on without an airlock, thinking that the positive co2 pressure would keep yeast and bacteria out. However, when I cold crashed, I put a sanitized airlock on and crashed for 24 hours. I never removed the lid, no secondary.

One other thing to note is the 3 gallons of headspace (only had an 8 gallon bucket available at the time for a 5 gallon batch). Could this be the cause? Or the foil without an airlock?

 

[RPh_Guy]

All of the photos clearly show a pellicle with 100% certainty.

@Miraculix and @brownni5 gave you pretty accurate info, so I won't rehash much of that.
Keeping it cold in the keg should generally suppress further microbial activity.

Headspace doesn't directly cause a contamination, only exposure to wild microbes. Air is filled with microbes which is why we generally keep the vessel sealed.

Instead of "open" fermentation, I would recommend using yeast nutrients (Wyeast nutrient dissolved in hot water and added directly to the fermenter), and aerating it thoroughly before pitching and again between 6 and 12 hours after pitching. I also recommend against cold crashing. Lowering the temperature causes a negative pressure that pulls in air, which does the beer no favors.

For cleaning I recommend a warm/hot PBW soak and then an acid rinse. Disassemble everything for cleaning.

Cheers

 

[Dog House Brew]

I do not see anything IMO. I’ve used 565 a lot and it looks similar to my results. I don’t think your fermenter size would cause issues. I use 8 gallon fermenters frequently for 5 gallon batches. As long as you use good sanitation, there should be no issues. Only issue I ever had was mixing StarSan with my tap water. It didn’t last and I had my only infection.

 

[RPh_Guy]

Those photos are not normal, so if yours looks the same, then you have contamination issues.

A lot of people mistake early pellicle formation for "yeast rafts".

 

[Dog House Brew]

Missed the first pic w the syphon.
Those bubbles are not normal.

 

[Miraculix]

Some mis-information here, and as someone who strives for pellicle production (ok, maybe not, but I do a lot of mixed ferments), I feel it necessary to dispell them.

1. As stated above, I don't see a remarkable pellicle, but neither do I see evidence to the contrary.

2. Pellicles are caused by exposure to oxygen in the presence of possibly wild yeast or bacteria. Oxygen exposure itself does not cause infections by either yeast or bacteria.

3. Infections can lead to over-attenuation if wild yeast is present. If only bacteria is present, then it will not attenuate further, at least not significantly so. Generally, pellicles are attributed to wild yeast, but bacteria can form them (we think), so there's really no way to know what is responsible for any one pellicle. Further, many wild yeast are alcohol-intolerant, crapping out around 5% ABV or lower. When we find one that isn't, we get excited!

4. An infection will not necessarily lead to bad flavor or reduced head-retention. All depends on what infected the beer/wort. Too much acid production can ruin head retention, but wild yeasts typically don't produce much acid. Bacteria (Acetobacter, Lactobacillus, and Pediociccus) are the big bacteria producers. In the presence of hops, these bacteria generally take a long time (months/years) to produce noticable acid. Acetobacter is the "worst" of these - it's the bacteria responsible for making vinegar. Nobody wants 5 gallons of malt vinegar on tap.

How soon after pitching did you notice this? Had you opened the bucket lid a bunch after primary was done? Very little is understood about pellicles, but they generally take a little while after the introduction of oxygen to develop.

Where is the misinformation in my post? What did you need to "dispell"?

 

[Mook]

Thanks all, this was very helpful. It seems like I do in fact have my first infected batch.

I tasted the somewhat carbed beer last night and it actually tastes great (so far). I will just have to drink quickly.

I also reached out to Drew directly, and he noted that he will usually replace with foil once the krausen falls.

 

[OnePlate]

That clearly is a pellicle, plus some yeast rafts. If you're lucky, the beer might be ok young but quickly get worse with time. You might find out that the beer has zero foam stability and that the general flavour is not as expected.

I dealt with exactly the same look multiple times and found out that it most certainly is because of oxygen exposure.

The beer won't be completely ruined but it will be way beyond what it could have been. I guess your bucket is not tight enough (mine wasn't...). One trick is to bottle as soon as possible, so that there is not much time for the bacteria to develop, but you need to have some experience so that you don't create bottle bombs by bottling too early.

I've bottled a couple beers with the "broken ice floe" look and they turned out ok since in the bottle there wasn't any O2 exposure. I let a small batch go un-bottled too long once and it turned to acetone and was sour enough to almost blow the top of my head off. I plated that one and there were big white bacterial colonies mixed in with the yeast and it actually discolored the agar from the pH change.

 

[Miraculix]

I've bottled a couple beers with the "broken ice floe" look and they turned out ok since in the bottle there wasn't any O2 exposure. I let a small batch go un-bottled too long once and it turned to acetone and was sour enough to almost blow the top of my head off. I plated that one and there were big white bacterial colonies mixed in with the yeast and it actually discolored the agar from the pH change.

I also had the feeling once that those guys are kind of producing vinegar like flavor over time. Took long for me as well when bottled, but they continued munching.

The first thing that was gone was taste and foam, actually, the expected taste was never there. The foam was also never there, gone long before any hint of sourness was detectable.

I somewhere read that those guys also like to chew proteins, which would explain the lack of foam.

 

[brew703]

All of the photos clearly show a pellicle with 100% certainty.

@Miraculix and @brownni5 gave you pretty accurate info, so I won't rehash much of that.
Keeping it cold in the keg should generally suppress further microbial activity.

Headspace doesn't directly cause a contamination, only exposure to wild microbes. Air is filled with microbes which is why we generally keep the vessel sealed.

Instead of "open" fermentation, I would recommend using yeast nutrients (Wyeast nutrient dissolved in hot water and added directly to the fermenter), and aerating it thoroughly before pitching and again between 6 and 12 hours after pitching. I also recommend against cold crashing. Lowering the temperature causes a negative pressure that pulls in air, which does the beer no favors.

For cleaning I recommend a warm/hot PBW soak and then an acid rinse. Disassemble everything for cleaning.

Cheers

Just curious why you say not to cold crash? Do you just transfer at fermentation temps and whatever hop debris is in the fermenter?
I use a mylar balloon with co2 and never had an issue. No oxidation or infections yet (knock on wood).

 

[RPh_Guy]

Just curious why you say not to cold crash?

I'm all about reducing oxygen exposure. "Spunding" into a purged vessel with a closed transfer is the ultimate way to do that on the cold side. Some logistical issues may need to be solved in order to do that, and it may or may not be worthwhile depending on your taste and brewing goals.

The OP wasn't using any method of preventing suckback during a cold crash, so there's pretty significant oxygen exposure that occured and should be prevented in the future (in my opinion).

 

[brew703]

I'm all about reducing oxygen exposure. "Spunding" into a purged vessel with a closed transfer is the ultimate way to do that on the cold side. Some logistical issues may need to be solved in order to do that, and it may or may not be worthwhile depending on your taste and brewing goals.

The OP wasn't using any method of preventing suckback during a cold crash, so there's pretty significant oxygen exposure that occured and should be prevented in the future (in my opinion).

I agree. Everyone doesn't have the ability to focus on low oxygen brewing, and I am one. I do try and prevent as much exposure as I can, such as purging my keg and doing closed transfer but oxygen still gets in when I dry hop.
I use a SSBT brew bucket so there is really no way of preventing some oxygen intake. So for, with my processes, I have not had any issues (cold side) but I know there will always be room for improvement. Down the line I would like to make some changes but for now I'm good with what I do.

 

[Alex4mula]

I'm going to agree with the ones who said it is nothing. I had that couple of times and never developed into anything. But it does scare some. Both times it came at 3-4 weeks. Cold crashed and tasted great.

 

[RPh_Guy]

I'm going to agree with the ones who said it is nothing. I had that couple of times and never developed into anything.

It's definitely a pellicle, so wild microbes are present.
A contamination doesn't always develop into something. Many times there won't be any noticeable off-flavor(s) or changes in pellicle characteristics.

 

[Miraculix]

It's definitely a pellicle, so wild microbes are present.
A contamination doesn't always develop into something. Many times there won't be any noticeable off-flavor(s) or changes in pellicle characteristics.

..... And it's also hard to taste the difference to the same batch without contamination, if there is not an exact replica of it present. As you said, sometimes it's a subtle difference and how should one know it's there? Little bit less hop character? Little bit higher attenuation? pH shifted a tiny bit? That's hard to recognise....

 

[Mook]

..... And it's also hard to taste the difference to the same batch without contamination, if there is not an exact replica of it present. As you said, sometimes it's a subtle difference and how should one know it's there? Little bit less hop character? Little bit higher attenuation? pH shifted a tiny bit? That's hard to recognise....

Quick update - the beer does taste great, maybe not as good as it could have been but still very tasty. I have shared with people who don’t realize there was any contamination until I mention afterwards, although maybe the saison character hides it.

One other thing to note is the color - I calculated this at a 5 SRM and it looks more like an 8-10. More evidence of oxidation from not replacing the foil.