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Old 03-21-2007, 06:18 PM   #1
casebrew
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Here's an intreresting link I found : <shttp://www.alphap.com/basics/compare.html>

With an interesting chart.

Check the right hand column, "recycle numbers". The O2 column is oxygen transmisiliby, lower is better.

Some stuff I noticed: #7 bottles pass only 1/2 as much as #1 bottles. So #7 is TWICE AS GOOD FOR BEER, as far as staling goes. #2, as in bucket fermenters, pass 53 times as much oxygen as a #1 bottle. So #7 plastic would be 100 times better than a plastic bucket. I'll repeat that:

#7 PLASTIC IS BETTER THAN #1 PLASTIC.

#7 PLASTIC IS 100 TIMES BETTER THAN A PLASTIC BUCKET.

So, if a plastic #2 bucket is just fine, then it just don't matter, does it?


Note also the CO2 transmissability column, that each of those plastics pass CO2 at 4 to 7 times the speed of oxygen. SO:

YOUR BEER WILL GO FLAT, BEFORE IT GOES STALE, IN ANY KIND OF PLASTIC.

I did some googling on the #1 carboys. All the sales literature seems to compare them to glass. Nothing to compare them to the mass market water jugs. No "Our jugs are better than #7 jugs because ______"
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Old 03-21-2007, 06:19 PM   #2
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Don't forget to take thickness into account. Does O2 permeability decrease linearly or exponentially with an increase in thickness?

I don't know the answer to that, but I know enough to ask the question...
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Old 03-21-2007, 06:37 PM   #3
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Here's the problem.

Recycle Code 7 means "other" plastic.

Quote:
Plastic ID Code "7" is for the other plastics except above mentioned 6 groups.
Source: http://www.kenplas.com/topic/recyclelogo/

Alternatively,

Quote:
Properties: varies according to constituent resins
Statistic: In 1999 there was minimal usage of resins in the 'other' category in plastic bottles.


Description: The category of "Other" includes any resin not specifically numbered 1, 2, 3, 4, 5, or 6, or combinations of one or more of these resins.

Packaging applications: Three and five gallon water bottles, certain food product bottles

Recycled products: Plastic lumber, custom-made products
Source: http://www.earthodyssey.com/symbols.html

Now, your website states that Polylactide is Recycle Code 7 - that DOES NOT mean that all Recycle Code 7 is Polylactide. It simply means that Polylactide is not one of the other six that can be recycled.

So, if you buy a bottle that is Code 7, it COULD be Polylactide; if it is, you're in luck.

It also could be pretty much anything else, which would put you SOL.
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Old 03-21-2007, 06:37 PM   #4
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Very interesting since #7 is listed as "Other" how would you know that you are getting PLA plastic or something else?

Maybe it is I don't know.
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Old 03-21-2007, 06:44 PM   #5
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Well, you'd order PLA plastic from your manufacturer---- the recycle code isn't there to help you spec out your purchase, really. It's there to aid in recycling efforts.
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Old 03-21-2007, 07:00 PM   #6
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I guess all those guy brewing in #7 have been just flat out lucky then? All of them?

Anybody got some examples of water bottles labeled #7, that are known to be somthing other than Polylactide? Anybody? Beuller?

But again, anydamn stuff is better than the ubiquitous #2 bucket.
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So far, I've had more experience thinking than I've had brewing....you don't think they are mutually exclusive, do you?

72 batches so far,
48 wine, mostly Loquat, peach, plum, prickly pear
23 beers and ciders
1 sauerkraut
1 Tequila, from a prickly pear wine experiment that didn't work. I call it "Prickly Heat"

 
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Old 03-21-2007, 07:02 PM   #7
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Do what you want to do - but your link proves nothing.
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Old 03-21-2007, 07:02 PM   #8
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I'm just happy that better bottles and fermentation buckets are 100% recyclable.

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Old 03-21-2007, 07:03 PM   #9
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Quote:
Originally Posted by casebrew
But again, anydamn stuff is better than the ubiquitous #2 bucket.
Meh, the bucket seems to work fine for a primary. If it ain't broke, don't fix it and all that...
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Old 03-21-2007, 07:13 PM   #10
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Quote:
Originally Posted by casebrew
I guess all those guy brewing in #7 have been just flat out lucky then? All of them?

Anybody got some examples of water bottles labeled #7, that are known to be somthing other than Polylactide? Anybody? Beuller?

But again, anydamn stuff is better than the ubiquitous #2 bucket.
I've aged two in plastic bottles and I didn't particularly care for either batch. I'm not 100% sure it's due to the bottle but evidence points. I'm doing a final test where I split my melomel into two vessels (out of necessity). I'll post the differences.
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