Decreasing oxygen permeability in HDPE2 container

I plan on doing a Flanders red and AmandaK's extract lambic using two 13 gallon hdpe2 barrel. Has anyone tried saran wrapping the whole barrel with just the airlock sticking out to reduce oxygen permeability?

Would it be better to do a 12.5 gallon batch to reduce headspace? To prevent a nasty blow out and losing a gallon of wort, let 10 gallons ferment first.
When fermentation dies down, add in another 2.5 gallons.

pic of barrels

I don't think adding more plastic is going to reduce the O2 exposure. The oxygen flows through the plastic itself IIUC. Stainless or glass would be the only option. The larger the volume the less the exposure rate matters, but it is still significantly higher than glass or very large wood barrels. I'm fairly happy with glass carboy with silicone stopper so far, but I've not kept anything longer than 8 months. The only year plus beer I kept in a corny keg.

I'm sure glass would be better but I'm clumsy and cheap. These were $18 a piece. Glass carboys would be about $40 each.

I don't know much about the physics of oxygen flow through materials, but maybe doing something like submerging it in water as much as you can would work? You could even deoxygenate the water by boiling it first.

Submerging in water sounds good but it's just going to take up more space than I really want to. I'll also have to buy some trashcans big enough for these.

There is a considerable amount of oxygen in water. Standard municipal water is outside the upper limit of what the dissolved oxygen meter I use at work is calibrated to look at. In tap water you should be able to source a table that shows relative ppm oxygen to water temp. Now I understand you are clumsy and cheap. I know they are smaller but better bottles rock. I hardly even get a pellicle to form when I do sours in them. You either have to deal with your permeability issue or pony up some moola. The reason I say that is because to make a difference on these two fermentors, you will eat up your savings over a better bottle or two by trying to make what you have something its not.

Are you suggesting that better bottles have lower O2 diffusion rate than HDPE? I've not seen a source for that result.

ne0t0ky0 said:

Are you suggesting that better bottles have lower O2 diffusion rate than HDPE? I've not seen a source for that result.

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http://www.faybutler.com/pdf_files/HowHoseMaterialsAffectGas3.pdf

This is a chart that keeps popping up

I'm going to try using these barrels without opening them during the fermentation. More oxygen is introduced when the removing the stopper and sampling than would permeate through in a few years. I'll wait till I find a good deal on large carboys to switch over.

Has anyone used these on a lambic? What were your results like?

Oldsock

Buckets really aren't THAT permeable, the big issue is their seals which tend to be hit or miss (especially if you are frequently opening them).

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The seals on these buckets look better than standard bucket fermenters. I think I'll put some sealant between the cap and the bucket to enhance the seal. Then leave it sealed for a year before I check on it

Better Bottles are PET which is less oxygen permeable than HDPE. The huge screw top on the lid is probably going to cause a lot more oxygen transfer than any other common beer storage out there.

ne0t0ky0 said:

Are you suggesting that better bottles have lower O2 diffusion rate than HDPE? I've not seen a source for that result.

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I am saying exactly that. Better bottle has published results of o2 diffusion testing, you don't see claims from anyone else do you?

So other than glass or stainless, I think better bottles are a great option. I use them and stainless.

I love my better bottles but I only have four and tying them up for a whole year isn't the best option for me right now.

Do what I did. Fill them all with sours then you HAVE to buy more

Brewing_on_the_Internet said:

I love my better bottles but I only have four and tying them up for a whole year isn't the best option for me right now.

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Well short of some spray on enamel/epoxy coating I think you're out of luck decreasing the O2 permeability. They appear similar to my Speidel 60L fermentors which are crazy with oxygen permeation compared to my 10gal kegs I use as fermentors. In a better bottle with better bottle stopper my sours don't look like they're doing anything interesting. My stainless, well is rather opaque, so I don't know what's going on at any given time, except I have opened them to not find a pellicle. Glass with the cheapie one size fits most stoppers allow for some pellicles to form from the permeability of the cheapie plastic stopper. I also have a barrel that is 15gal that I coated in a 50/50 beeswax and caranuba wax mixture. I left on head unwaxed and waxed all the staves. This just finished aging an imperial stout and now has a sour imperial stout.

I wouldn't worry that much but the worst that will happen is you get a little stronger acetic acid character because with a little oxygen brett will produce some acetic acid. I think it's a misconception that everyone is getting acetobacter/gluconobacter in their beers giving them acetic character. I believe its a function of small volumes, oxygen and brett. If you had gluconobacter or acetobacter you'd have a mother growing in there, and I haven't seen anyone pulling a mother out of anything. If you've ever handled a vinegar mother they feel so gross.

smokinghole said:

Well short of some spray on enamel/epoxy coating I think you're out of luck decreasing the O2 permeability

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Epoxy coating on the outside looks like it could work pretty well

http://www2.dupont.com/Powder/en_US/assets/downloads/literature/1_Internal_&_External_Coatings_for_Water_Transportation_Pipelines.pdf

smokinghole said:

I think it's a misconception that everyone is getting acetobacter/gluconobacter in their beers giving them acetic character. I believe its a function of small volumes, oxygen and brett.

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I can't speak from experiance but I've read on the Mad Fermentationist that "acetobacter needs lots of oxygen to convert ethanol to acetic acid"

http://www.themadfermentationist.com/2008/05/with-re-re-release-of-wyeasts-roeselare.html

I actually like the strong vinegar taste in Rodenback grand cru. For the lambic it's not supposed to be there so I'm trying to find ways to minimize it with the equipment I have.

How does the sour imperial stout taste? Do the dark malt flavors combine well with sour?

Brewing_on_the_Internet said:

http://www.faybutler.com/pdf_files/HowHoseMaterialsAffectGas3.pdf

This is a chart that keeps popping up

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Can't help but notice that "Saran" (10th line down in that table) has the lowest permeability @0.005. Now also keep in mind the actual working thickness of the "film" for each poly listed. Saran (wrap) being very, very thin compared to, say your HDPE container or a typical PET one. So to compare one layer of Saran wrap with your HDPE tank walls, there is a factor in the order of 200-500 involved, just by guessing.

Added:
I just read the whole AmandaK's Lambic thread, and she claims the plastic fermentor is key to her success, definitely during primary fermentation, the first month or so. Do you intend to keep the beer in your plastic barrels for aging too, without racking at all?

If you read carefully it's a chart about hose materials. So the saran (poly trifluoro chlororeythele) is a hose not an extremely thin sheet from your kitchen. It's interesting to see that chart because a PET hose is almost 10x more resistant to oxygen permeation.

I've made vinegar on purpose and it either takes forever or you just need to leave it with a cloth over the top almost. It takes open exchange with the air almost, so your quote from Mike jives with my experience as well.

The imperial stout is light on the roast. I went crystal heavy (caraaroma, and caramunich) then a little roasted barley, with the remainder of my black/roasted grains being a high proportion of midnight wheat. So far the flavors are working well. I had to wait to drink Tart of Darkness before I decided to brew the beer. I liked it enough but didn't feel Tart of Darkness was much of a stout, it came off as a black IPA to me. Just enough grain to give it color with out much flavor to back up the color. So I decided to up the roast in a smoother fashion.

IslandLizard said:

Added:
I just read the whole AmandaK's Lambic thread, and she claims the plastic fermentor is key to her success, definitely during primary fermentation, the first month or so. Do you intend to keep the beer in your plastic barrels for aging too, without racking at all?

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That's a great post. The lambic I'm planning is the same extract recipe she used.

I was planning on keeping it in the plastic barrels the whole time. I figure if I don't open them for a year it'll be exposed less oxygen then if I were to transferring to a secondary.

smokinghole said:

I am saying exactly that. Better bottle has published results of o2 diffusion testing, you don't see claims from anyone else do you?

So other than glass or stainless, I think better bottles are a great option. I use them and stainless.

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The study in question:

http://www.better-bottle.com/pdf/CarboyPermeabilityStudy.pdf

My reading of that would put a better bottle in line with a glass carboy; it still move a tiny amount, but as mentioned in the study, opening/closing of the bottle will introduce far more. For practical purposes I'd say it's equivalent w.r.t O2 diffusion to that of glass.

Awesome!