FrEwing

High Density Polyethylene containers & Taste

15 posts in this topic

Hi All again, I'm trying to keep my startup costs low and have had contact with a number of folks selling High Density Polyethylene containers and tanks. The costs are much lower than stainless but I'm concerned about the long term effect of spirits on the material and the flavor profile of my liqueurs. I'm interested to hear any experiences anyone has with these containers and if the material had any effect on flavor over time? I had contact with one fellow who is using them to store gin and vodka and has had seen no change in the flavor of his spirits. Any other feed back would be appreciated.

Thanks Again

Dick G

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Hi Dick,

I am attaching a chemical resistance sheet for tanks from Chem-Tainer. It lists reagents (acids, alcohols, etc) and the container material as well as fitting materials. I know many wineries use HDPE, although for fermenting. I also believe most GNS is shipped in totes made out of HDPE.

Hope this helps you (and anyone else looking).

Todd

Chemical resistance for tanks.pdf

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Good chart but all it really say is that HDPE/PP tanks will not lose serviceability due to contact with ethanol. Says nothing about flavor transfer to the spirit.

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Thanks todd, This chart is very useful. I found whiskey on page 4. Apparantly HDPE is compatible with spirits which makes more more compfortable consideering these tanks. Like all good whiskeys, liqueurs develope complexity of flavor with aging. My concern is how this material effects flavor over time. I would love hearing from any folks who have used or are using HDPE for storage of their spirits and if they have any experience with flavor changes or not.

Todd thanks again.

Dick G

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Good chart but all it really say is that HDPE/PP tanks will not lose serviceability due to contact with ethanol. Says nothing about flavor transfer to the spirit.

Thanks for the comment J'ESP.

Dick G

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HDPE without plasticizers should not affect the flavor of anything. But even the densest HDPE may have some porosity at the surface, and this provides sites where trace amounts of other materials may be absorbed. So, the concern would be if residual flavors from long term storage of one product could later impart something to the next product. If only pure ethanol water mixtures are there, likely no problem. Or if the same product is repeatedly stored, likely no problem. But keeping the HDPE clean is also important, because if a contaminant layer can form on the HDPE, then that layer determines the properties of the container. This all presumes the highest grade HDPE is used. Same for PP. Exposure to extreme caustics or acids could degrade the surface of the materials enough over time to increase their porosity or ability to absorb traces of other materials, which might be considered when using them for cleaning.

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Hi All again, I'm trying to keep my startup costs low and have had contact with a number of folks selling High Density Polyethylene containers and tanks. The costs are much lower than stainless but I'm concerned about the long term effect of spirits on the material and the flavor profile of my liqueurs. I'm interested to hear any experiences anyone has with these containers and if the material had any effect on flavor over time? I had contact with one fellow who is using them to store gin and vodka and has had seen no change in the flavor of his spirits. Any other feed back would be appreciated.

Thanks Again

Dick G

Assuming its food grade PE containers your talking about. If the spirit is less than 50% ABV then I think you will have no taint problems. Your real issue will be the PE container taking up components from the spirit, especially if its Gin. You can never get the Juniper smell out of PE it seems.

I did read there is an issue with Ethanol (>80%ABV) washing out the plasticizers in PE and causing them to become brittle, hence liable to crack, in my opinion the chemistry of plastics does not support this.

I am not sure with the laws in the US, but in Australia we must have all our tanks and vessels volume calibrated (to ensure accurate excise controls), and this is impossible with a semi-rigid masterial such as PE. The more you put into the tank, it is likely to balloon out at the base, effecting the dip versus volume charts. Hence plastic tanks are specifically prohibited here.

rich..

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You guys are really helpful. I'm getting so much good information and an education about things I would only learn about with experience. So far today I've had a long conversation with a GNS supplier re: plasticizers and some uses of HDPE UN approved containers and totes, and then I come back to the forum and learn as they say, more of the rest of the story. The headsup on reuse and retention of flavors in the surface impurities of the material was very concerning. I will be making a few different natural fruit based flavored liqueurs. Not being able to reuse a tote or drum for fear of flavor contamination seems to point me toward stainless as the best alternative. Expensive initially but more than likely the least expensive approach over time. Thank you again for all your insights and advice. If anyone has any additional info, please pass it along I don't want to end this discussion, it is very enlighening. I hope it helps others as well.

Thanks

Dick G

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No question about it, HDPE will absorb flavors, but if you have a container for each product, you'll not have cross carryover.

In other words, you make-up a batch of really stinky fennel infusion for something. Later, try putting vodka in that thing, and it will have a fennel flavor...but if you use it for fennel again, you'll be a happy guy. Guess how we know that.

Same deal with black stains from nocino - they'll make a mess of your angelica, but they're fine for nocino.

Bottom line is that HDPE is so inexpensive that it's difficult to justify stainless.

I'm also not convinced that stainless is either flavor free or stain free, or free of carryover...or easy to clean.

The guys moving the really big stuff are starting to use mild steel containers with some sort of ceramic coating inside. I guess that's a problem if you're in the 80,000 gallon league. Really big totes are becoming unavailable in stainless.

Try HDPE, you'll be surprised.

Good luck,

Will

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I've had some discussion with a large supplier of neutral spirits; their product is shipped in HDPE drums at 95% ABV.

Will, I'm intrigued by your comment re: stainless possibly not being flavor free. Is this based on your experience? If so, did it vary by stainless grade?

As I'm sure many of you know, there are many different types of stainless, so I'd like to narrow down any critique of stainless to particular grades.

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Jedd,

I doubt that the inside of stainless drums is without porosity. I doubt that it's highly polished. In that case, it stands to reason that a kind of deposition of flavor components into porosity in HDPE happens also with stainless. Also, in the case of nocino in a tight-head stainless drum, I wonder what cleaning protocol would assure removal of those black stains since you can't reach in there and scrub.

Our concern about stainless has to do with a tinny effect we think we detect when using stainless (316, i think) for proofing very neutral vodka. We don't get that from the HDPE.

In either case, this is also the only time carryover is a problem. I think that an HDPE barrel used for a fennel infusion would not contribute enough flavor to wormwood or anise infusion later to be detectable because the wormwood or anise would be so strong. It's only when doing something very neutral that it's noticeable.

...and I think it might be that the aroma from the drum might be more noticeable than what actually gets into the product (you can smell it when you open the drum, but you might not taste it in the product).

Good luck,

Will

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Hi Gang. last week after I got all those great responces , I recalled a school chum I ran into during our class reunion earlier this month. He's a PhD Chemist invloved with a company in NJ, teaching at a local college and doing consulting work. I copied the responces I had gotten up to my question up to Rich Morgan's reply and attached it to an email to George Maass, asking the same questions about HDPE tanks and his ideas. The following is his reply. Hope it adds to everyones data base and understanding of the material.

Dick G

Hi Dick,

This is a coincidence. Just yesterday, I put your business card on the top of my computer & said to myself, I must write to Dick today. We use stainless tanks in our business (refer to www.purestcolloids.com) , but that is mostly because we have to have FDA approval.

I read some of the responses to your letters & I agree for the most part. I believe, if you use a good quality HDPE, you will not have to worry about resin leeching into your product. You probably will, however, notice as we have that, after a period of time, your product will be absorbed by the walls of the HDPE container. After a period of time, this can be absorbed back into your product, so you would have to try this to find out if this makes any noticeable difference.

Because of the difference in price, if I were you, I would buy a small HDPE tank and try it with your strongest product. Expose the tank to some heat and sunlight, too, to see if anything happens. We use a lot of HDPE containers in the lab and all of our products are bottled in HDPE. We must have about 50 stainless tanks in production, ranging from 50 to 600 gal.

It was great to see you again & feel free to ask me about anything I may know anytime. I, too, would like to stay in touch.

Best wishes,

George

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Assuming its food grade PE containers your talking about. If the spirit is less than 50% ABV then I think you will have no taint problems. Your real issue will be the PE container taking up components from the spirit, especially if its Gin. You can never get the Juniper smell out of PE it seems.

I did read there is an issue with Ethanol (>80%ABV) washing out the plasticizers in PE and causing them to become brittle, hence liable to crack, in my opinion the chemistry of plastics does not support this.

I am not sure with the laws in the US, but in Australia we must have all our tanks and vessels volume calibrated (to ensure accurate excise controls), and this is impossible with a semi-rigid masterial such as PE. The more you put into the tank, it is likely to balloon out at the base, effecting the dip versus volume charts. Hence plastic tanks are specifically prohibited here.

rich..

I store less than 30%abv in HDPE. Any at higher % is ready for barreling or botteling so it does not stay in plastic for long just in case it picks up a taste. I will watch this thread to see if anyone KNOWS if HDPE causes taste problems.

Rich, I am down south of you over the water. I got my manufacturing licence late last year. Excise wanted me to pay Weights and Measures to calibrate my still, fermenter and any storage vessels. After quite a few emails with cut and pastes of relevent sections of The Act, and a few phone calls I finally convinced them that I did not have to get any volumetric calibrations done. It can all be measured much more accurately by mass.

I have "trade scales" that have to be recalibrated each year, hydrometers with certificate of accuracy, and thermometers with a statement of accuracy. I am at liberty to use plastic storage containers if I wish!

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Does anyone store high proof spirits in HDPE? We are considering some tanks for very short term storage - a week or less - but with high proof spirits - 95% ABV. Safe? Flavor transfer risk? I see Jedd Haas's post which indicates its probably OK but wanted to check and see if anyone is doing it.

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