For those of you that are thinking of using a beer can as a pot, please read this information compiled by Dlarson.
The entire thread related to the lining in beer can pots can be accessed by clicking on the little white box on the left side of Dlarson's name.
Re: Plastic Lined Beer Cans as Pots
by dlarson on Fri Dec 05, 2008 4:28 pm
OK, here's what I know.
Pretty much any beer can is going to have an interior coating over the aluminum (pg. 26).
Preliminary Industry Characterization:
Metal Can Manufacturing--Surface Coating wrote:Waterborne coatings contain a polymer or resin base, water, and organic solvent. The
organic polymers found in water-based coatings include alkyds, polyesters, vinyl acetates,
acrylics, and epoxies, which can be dissolved, dispersed, or emulsified. The water acts as the
main carrier or dispersant, while the organic solvent aids in wetting, viscosity control, and
pigment dispersion.
...
Beverage can manufacturers use waterborne coatings extensively. Waterborne coatings
are used for 2-piece beverage can base coats, overvarnishes, inside sprays, and rim coats.
The interior coating of a beer can is not developed to withstand boiling water at 212 degrees (pg. 29).
Preliminary Industry Characterization:
Metal Can Manufacturing--Surface Coating wrote:In general, coatings must exhibit resistance to chemicals, flexibility, and adhesion to
the metal surface. Coatings for beer and certain beverage cans must be able to survive an
aqueous pasteurization cycle of 20-30 minutes at temperatures ranging from 140F to 160F
Heating plastics promotes leaching of toxins into the food.
Studies have shown when cans are heated in the manufacturing process, BPA leaches out of the linings. Foods are first sealed in cans and heated to kill bacteria in the food. Cans are heated to temperatures between 116 C and 121 C, and the length of time varies according to the type of food.
...
Note: This testing also included two beer cans and found they leached between 8 and 9 parts per billion of BPA. As well, a can of apple juice leached 18 parts per billion.
Ziploc freezer bags do not leach toxins so freezer bag cooking is OK (FAQs Page). And since Ziploc may be biased, here's a second resource stating that Polyethylene bags are safe.
My conclusion is that boiling water in just about any aluminum can is unsafe. If the makeup of the internal coating of Heineken 24oz cans can be determined and the coating is of safe materials that's great. But until then it is logical to assume that there is no difference between the Heineken 24oz cans and most other aluminum cans.
Freezer bag cooking, in contrast, is safe until proven otherwise.
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epilektric