“Not CAN you can wine, MAY you can wine!”
The grammar police can be infuriating, especially when the “error” has little impact on understanding. Who cares if you confuse “can” and “may” or end a sentence with a preposition (“Who did I give my canned wine to?”) or use a little hyperbole (“This canned cider is literally the best cider I have ever tasted!”) if the meaning is still clear?
In wine production and other areas of food science and technology, however, precision in word choice and phrasing is critical to prevent quality issues. Pity the poor intern who confuses “sulfur” (for powdery mildew) and “sulfites” (the preservative) because of poorly written instructions, or who added 1% w/w tartaric acid instead of 1 g/L tartaric acid – it happens!
Canned wine – what’s in your liner?
For wine or cider in aluminum beverage cans, the use of precise terminology is especially important when selecting the appropriate can liner. The liner is a 1-10 micron layer of polymer that coats the can interior to maintain quality and prevent package failure. A typical table wine or cider stored in an unlined aluminum can would start leaking within weeks due to aluminum corrosion and would also take on an intense odor of rotten eggs due to reaction of sulfites with aluminum to produce hydrogen sulfide (H2S). Recent research by our groups at Cornell University has shown that the choice of can liner material is critical to slow these processes and ensure adequate shelf life (Montgomery et al., 2023; Sheehan et al., 2024). In our experiences, we have found three acceptable liner materials for sulfited beverages in cans [1].
- Bisphenol A (BPA) epoxy [2]
- valPure® V70, a BPA – non intent (BPA-NI) epoxy
- aTULC, a much thicker laminated polyester
These materials will result in low (<10 µg/L) H2S accumulation after ~6 mo storage at room temperature (Montgomery et al., 2023). These values will be around the sensory threshold of ~1 µg/L, and comparable to typical values observed in glass-packaged wines. By comparison, wines canned with unacceptable liner materials like acrylic or thinner forms of polyester may accumulate > 10 µg/L H2S in less than one week!
OK, we need the right liner. Seems easy. What’s the problem?
In brief, beverage can liner terminology is a mess. The industry jargon and terminology around beverage can liners are so convoluted that it’s challenging to know if a particular liner will work for your product. A summary of key terms used in the industry to describe liners is shown in the table below. Many of these terms (e.g. “Gen II”, “BPA-NI”, “Hard-to-Hold”) are ambiguous and describe multiple types of can liner materials, including materials unsuited for sulfited beverages. This problem is exacerbated because many wine and cider makers don’t buy directly from can manufacturers – it is common practice to purchase from can suppliers who may also do the artwork and/or packaging. These suppliers do not always use terminology in a manner consistent with can manufacturers.
