Contamination from Dry Hops?

[Gavin C]

This is somewhat confusing as that would indicate carbon dioxide which should have killed the mold, right?
.

The bubble does not indicate CO2 I'm afraid. Temperature/pressure changes air will burp out from time to time.

CO2 being present doesn't exclude the chance of infection.

Edit: A beer fermenting as result of bacteria will result in CO2 being produced. Plenty of microbes to do that.

Lovely clear looking beer.

Thanks for the update.

 

[unionrdr]

Well, as I currently understand it from the more science-oriented folks on here, the O2 doesn't " layer" above the Co2, as was previously thought. The o2 is absorbed by the Co2. But there is a point of no return, it seems. That point where there's enough o2 absorbed to allow any few nasties floating around to be fruitful & multiply. That seems to be, perhaps, the point you reached?

 

[ffaoe]

Never had an infection from dry hopping, although I think the source you get your hops from might have something to do with it.

The reason I say this is when I bought a pound of Azacca hops from Hops Direct I found a big, flat, brown thing in my hops that looked like a flat, dry piece of ****. I have no idea what it really was but I'd say there's at 60% chance a flat, dry piece of **** made it into my hop bag. I think these hops came directly from the farm and obviously quality control wasn't the best. Needless to say I never dry hopped with that bag. I can easily imagine a small piece of the mysterious brown substance being carried into the beer by being inside or on top of the hops.

On the other hand I've gotten leaf hops in smaller bags from Hop Union that seem like they have high quality control. These guys actually take measures to scrub the oxygen from your bag, etc. I would dry hop with something like that any day of the week. Additionally, the pellet hops I buy from Yakima Valley Hops are of great quality. I have never had a problem dry hopping with them.

I had something similar happen recently with a half pound of Citra hops from Fresh Hops. Towards the bottom of the bag I found a clump of what looked like a small piece of sh**. I pulled it apart and it was a long, thin, black, almost rubber looking thing. It had no smell to it but I ended up throwing away about one ounce of the surrounding hops. Who knows what it really was, it could have been a piece of ****, or just something that sheered off processing equipment.
I've never had an infection from dry hopping, but I'm only going to be using these hops for the boil.

 

[Gavin C]

Well, as I currently understand it from the more science-oriented folks on here, the O2 doesn't " layer" above the Co2, as was previously thought. The o2 is absorbed by the Co2. But there is a point of no return, it seems. That point where there's enough o2 absorbed to allow any few nasties floating around to be fruitful & multiply. That seems to be, perhaps, the point you reached?

Gasses just mix. Nothing more complex than that. It was never previously thought otherwise. Seems to be a common misconception among brewers unfortunately.

Its lucky for us that this is indeed the case. If CO2 did form a blanket the lower 0.2% of our atmosphere would be pure CO2 and none of us would be alive to talk about beer, hops or much of anything.

 

[joshesmusica]

Gasses just mix. Nothing more complex than that. It was never previously thought otherwise. Seems to be a common misconception among brewers unfortunately.

Its lucky for us that this is indeed the case. If CO2 did form a blanket the lower 0.2% of our atmosphere would be pure CO2 and none of us would be alive to talk about beer, hops or much of anything.

You sure? You don't think that our ancient, ancient ancestors would've evolved into something that took in co2 rather than o2?

 

[JonM]

I'll add my two cents here since I recently used a secondary for the first time in a long time. ( I needed the fermenter empty and didn't have available kegs, and this is a recipe that needs long term aging.)

Anyway, I filled the secondary to the tip-top with starsan and then, using a racking cane, carboy cap, and co2, pushed all the starsan out, making a sanitized vessel that is filled with nothing but co2.

Then I hooked the co2 up to a second carboy cap/racking cane setup in the fermenter, and pushed the beer out with co2 and into the secondary (through the same racking cane that had evacuated the starsan) allowing the co2 to escape through one of the little ports on the carboy cap. Overkill? Probably. But little to no risk of oxidation and minimal risk of infection.

It's been a month or more and the top of the beer is clear.

 

[unionrdr]

Gasses just mix. Nothing more complex than that. It was never previously thought otherwise. Seems to be a common misconception among brewers unfortunately.

Its lucky for us that this is indeed the case. If CO2 did form a blanket the lower 0.2% of our atmosphere would be pure CO2 and none of us would be alive to talk about beer, hops or much of anything.

I have read it on here over the years. But they do mix,...just to the point where the o2 mixed in can start to have an effect. That's the way it seems, anyway? And trees, etc absorb Co2 for photosynthesis & give off o2, so it all balances out. But in the limited environment of the fermenter, secondary, whatever, it's a bit different story.

 

[joshesmusica]

I'll add my two cents here since I recently used a secondary for the first time in a long time. ( I needed the fermenter empty and didn't have available kegs, and this is a recipe that needs long term aging.)

Anyway, I filled the secondary to the tip-top with starsan and then, using a racking cane, carboy cap, and co2, pushed all the starsan out, making a sanitized vessel that is filled with nothing but co2.

Then I hooked the co2 up to a second carboy cap/racking cane setup in the fermenter, and pushed the beer out with co2 and into the secondary (through the same racking cane that had evacuated the starsan) allowing the co2 to escape through one of the little ports on the carboy cap. Overkill? Probably. But little to no risk of oxidation and minimal risk of infection.

It's been a month or more and the top of the beer is clear.

Pressurized transfer sounds awesome! I wish I had that ability!

I had the same thing happen with my Pumpkin Ale, that I needed the larger primary. Except I didn't have enough to fill it to the top. So I just racked onto some fermentables (recipe called for dark brown sugar, so I just add another 100 grams). Been 2 weeks in the secondary, plan on bottling tomorrow.

 

[watermelon83]

These are super common images on HBT and elsewhere

Another secondary with massive headspace and an infection.

The problem is not the hops it's all the lovely air in the secondary vessel that you racked the beer to. Plenty for the microbes.

Secondaries should have as little headspace as possible to reduce oxygen availability and surface area for the ever-present airborne microbes.

Forget the idea of a CO2 blanket. It doesn't exist and the increased partial pressures of CO2 in the fermentor is gone the instant you rack the beer.

This looks infected for sure. You should post these great pictures in the post your infection thread. Aside from the orientation they are really sharp. Thanks for posting them. Sorry for your loss.

Do you have any proof of the highlighted portion, it goes against what I would consider to be reasonable sense. I just want to know it's not.

Edit: the pressure thing is obviously silly, but pure C02 is still heavier then normal breathing air. Every time I've racked the secondary kicks airlocks bubbles for awhile.

 

[watermelon83]

Honestly, I think that is a simple wet mold. If the hops had been saturated in beer it would not have happened. Since the mold had food below and a dry environment above the beer line to grow, it did.

 

[Gavin C]

Do you have any proof of the highlighted portion, it goes against what I would consider to be reasonable sense. I just want to know it's not.

Edit: the pressure thing is obviously silly, but pure C02 is still heavier then normal breathing air. Every time I've racked the secondary kicks airlocks bubbles for awhile.

Rack to a secondary or add anything to a liquid with dissolved CO2 and you will cause some CO2 to come out of suspension. The result is bubbles in your airlock. All that's happened is CO2 is coming out of suspension assuming your not adding anything to create a true second fermentation.

The non-existence of a CO2 blanket or a gas blanket of any kind in the known universe is quite plain. For proof look no further than yourself. You and all mammalian air-berating life exists. If a CO2 blanket formed the lower 0.2% of our atmosphere would be CO2 and we would not be alive.

Denser gasses do not form layers in this manner.

Rack your beer to an air-filled vessel and you have beer and air above it. Purging with CO2 will of course minimize this but all gasses are constantly mixing. They simply don't behave in this manner for any sort of appreciable time-frame.

There is a good youtube video of a tin-foil boat floating on a heavy gas, something hexafluoride if memory serves. Usually it gets posted the minute anyone disputes the absence of the magical blanket.

It's quite hard to post evidence of a negative. It's simply not something that exists. Keeping a fermentor sealed with an airlock allows the headspace to be filled with CO2 as a result of fermentation. A closed system almost. The gasses are still diffusing through the bung, the starsan etc, but it's very slow.

Open the system, rack the beer and this is gone. Sure you kick some out of suspension and the bubbles will make you feel good. That's OK. The increase in partial pressures of CO2 is going to be negligible though. Hence the need for small headspace and the design of beer and wine bottles we all come to view as normal.

A secondary vessel for long-term storage is just that. A great big bottle. Fill it like you fill any beer bottle. All the way to the neck.

The kinetic theory of gasses is not new. Purging vessels with inert gasses, minimizing headspace and keeping vessels as tightly sealed as feasible are the way we brewers offset the effects.

https://en.wikipedia.org/wiki/Kinetic_theory

 

[joshesmusica]

Rack to a secondary or add anything to a liquid with dissolved CO2 and you will cause some CO2 to come out of suspension. The result is bubbles in your airlock. All that's happened is CO2 is coming out of suspension assuming your not adding anything to create a true second fermentation.



The non-existence of a CO2 blanket or a gas blanket of any kind in the known universe is quite plain. For proof look no further than yourself. You and all mammalian air-berating life exists. If a CO2 blanket formed the lower 0.2% of our atmosphere would be CO2 and we would not be alive.



Denser gasses do not form layers in this manner.



Rack your beer to an air-filled vessel and you have beer and air above it. Purging with CO2 will of course minimize this but all gasses are constantly mixing. They simply don't behave in this manner for any sort of appreciable time-frame.



There is a good youtube video of a tin-foil boat floating on a heavy gas, something hexafluoride if memory serves. Usually it gets posted the minute anyone disputes the absence of the magical blanket.



It's quite hard to post evidence of a negative. It's simply not something that exists. Keeping a fermentor sealed with an airlock allows the headspace to be filled with CO2 as a result of fermentation. A closed system almost. The gasses are still diffusing through the bung, the stars etc, but it's very slow.

Not to mention that in the closed system of the primary, the yeast will consume all of the oxygen present. According to the book about yeast by jamil and Chris white, all of the oxygen in the wort will be consumed within 30 mins of inoculation! I'm assuming any oxygen in the headspace early on is consumed just as quickly, especially with a krausen exposed to that headspace.

 

[Gavin C]

I'm assuming any oxygen in the headspace early on is consumed just as quickly, especially with a krausen exposed to that headspace.

I think it's more a case of the partial pressure of oxygen being diluted lower and lower. With CO2 production the concentration of CO2 increases and the resulting CO2 richening gas is burped out the airlock. As fermentation proceeds the partial oxygen pressure will become negligably low with the partial CO2 pressure approaching but never reaching 100%.

There very well may be oxygen absorption initially, (not a bad thing of course at that point) but I would suggest it's not the main player.

 

[unionrdr]

That's the question, then, isn't it? How much o2 is absorbed/mixed into the Co2? Then how much is " burped off" after that percentage of absorption is reached? And how long does it actually take, since, at this point, nasties can get the air/o2 they need to reproduce?

 

[Gavin C]

Almost all of the O2 in the headspace of the FV (assuming no leaks) will be eliminated. No doubt about that. The partial pressure of 02 will be close to zero without ever getting there.

O2 absorption won't occur as it can't go against the concentration gradient of dissolved O2 in the beer intentionally added by the brewer.

This is an entirely irrelevant point IMO and not an issue.

 

[SatanPrinceOfDarkness]

There's a Facebook group and website called Milk The Funk that is pretty expert at identifying things like this. To my eye, that white stuff looks a bit like a Brett pellicle I have going, except that yours is broken up by the hops. Is the white stuff a very light, almost feathery layer? Pellicles form to keep oxygen out of wort when microorganisms want it that way. Supposedly they go away on their own eventually (well after the beer has been funked of course). It's usually recommended that you wait to transfer until the pellicle goes away. Plus, if it is mold it will only become more apparent.

 

[m00ps]

Not to keep straying too far off topic but I though we were breathing like ~80% nitrogen......

 

[unionrdr]

I don't think it's irrelevant, as gases do mix to a point. Just wondered how long, etc, since some more scientific types brought it up some time ago now.

 

[ncbrewer]

Do you have any proof of the highlighted portion, it goes against what I would consider to be reasonable sense. I just want to know it's not.

Edit: the pressure thing is obviously silly, but pure C02 is still heavier then normal breathing air. Every time I've racked the secondary kicks airlocks bubbles for awhile.

This video is really interesting: [ame]https://www.youtube.com/watch?v=_oLPBnhOCjM[/ame]
It shows that the denser gas doesn't stay on the bottom.

 

[unionrdr]

So I assume I should've said diffusion? They do mix, but at different rates, depending on the gravity of the gasses. Assuming the gravities of o2 & Co2 to be similar to the first experiment, than they do mix, or diffuse into each other over several minutes time.

 

[watermelon83]

Thx ncbrewer!

 

[danbme]

So the beer is done. I am worried it might get people sick as one friend did say it gave him the ****s. I have had some but have not gotten ill. I plan on drinking more for research purposes.

Will a steri-pen kill the bad stuff and allow us to drink this beer?

 

[unionrdr]

What gave him the Hershey squirts was the live yeast in the beer. Home brew has that effect until your system gets used to it.

 

[joshesmusica]

Any unfiltered beer or bottle-refermented (conditioned) beer will have yeast still in suspension, not just home brew.

Those that aren't used to it (aka the BMC crowd) will definitely experience some of that. Though I will say, even if your system is "used" to it, drink a few in a night, and you're still likely to get a little.

 

[unionrdr]

I've found that allowing hop sacks to float, no matter how much boiling & sanitizer soakings, can get funky. When I dry hop & dry pepper my Hellfire IIPA soon, I'm going to use one of my new 2 gallon bags with a sanitized shot glass to sink it. I think keeping it away from mixed Co2/o2 in the headspace will help...