First off, I can't answer your question, since I share it.
Secondly, I think this points out valid gripe with certain
blenders/producers/distributors. They really *should* datestamp their
tins. GLP gives us the precise day, which is ideal... and McClelland
gives us (if I grok their scheme) a 4-digit "batch number" + 2-digit
year. For those that don't, however, answers to the questions above, and
questions like it, help the consumer get as close as possible. We have
a few things to look at:
- the tin (sizes, shapes, metal colors, etc.)
- the tin label (design, fonts, copyright, content,
paper/plastic stock)
- importation and warning labels
- vendor's price tag/markings
One of my local B&Ms (which I trust) employs a year/month marker on
their price tags, and I was able to see (and later confirm through
label changes) that they had some tins which were several years old on
their shelves.
The problem with consumers like us compiling an authoritative list is
that we're downstream from all the potential sources of information:
blenders, producers, distributors, and vendors. Plus, I think there are
cases where variation in label or tin occurs based on the availability
to the blenders/producers/distributors. For example, if Producer X used
both silver and gold "tin bottoms" for a period of years, but later
standardized on the gold, this leaves us only with a way to wrap a known
timeframe around the silver bottoms. And even then, the silver
bottoms would take a while to clear through the warehouses,
distribution channel, shops, and so forth - which muddies the waters
even further.
So, it seems like it would be non-trivial for even a concerned consumer
to notice, understand, and date all changes that do occur with blends
they're interested in. Even people well-acquainted with, or even in,
the industry - how many of *those folks* do we expect would track things
of this nature with an eye on eventual tin dating? If there is such
information available (to Google), I've not been able to locate it.
Cheers,
Jason