It has been mentioned about the "safety" of using kits by their sell by dates. It is perfectly OK to use a kit after its sell by date, but you should change the yeast. The sell by date is more to do with the yeast than the contents of the tin (after baked beans last almost forever). It is OK as long as the tin has not blown out, and there are no signs of rust. Also if the tin is badly dented (has creases in it) then you should be careful as the coating inside the tin could be damaged and this would then mean the extract is in contact with the aluminium.
So, if you local shop is flogging off out of date beer kits - go for it!!
Sell By Dates
I'd second the advise above - I've used old cans with a new yeast without any problems.
I spent many years as an engineer in a cannery, the advise given above is pretty much spot on - avoid dented cans, unless you dented it yourself and can use it immediately, and reject blown cans (with bulging ends) as this is an indication of bacterial spoilage.
A blown can has either leaked at some point allowing bacteria in, or the contents have not been correctly processed. Very slight bulging on the ends is sometimes evident when cans have been stored for a very long time, but there will be no movement - a 'blown' can will continue to expand until it literally 'blows', and they can go with quite a bang!
The only thing I'd add is when checking for rust, rust on the outside is not uncommon when the plating rubs off, this isn't a problem. Rust inside the can, however, is a problem and the can should be rejected - pay particular attention to the area of the side weld when the lacquer is thin. The contents, particularly if acidic (fruit juices), can eventually eat through the lacquer to the steel.
Also, don't store (unopened) cans in the fridge - the low temperatures can cause the latex in the seam to contract, its possible that this can cause the seam to leak, causing spoilage later.
I spent many years as an engineer in a cannery, the advise given above is pretty much spot on - avoid dented cans, unless you dented it yourself and can use it immediately, and reject blown cans (with bulging ends) as this is an indication of bacterial spoilage.
A blown can has either leaked at some point allowing bacteria in, or the contents have not been correctly processed. Very slight bulging on the ends is sometimes evident when cans have been stored for a very long time, but there will be no movement - a 'blown' can will continue to expand until it literally 'blows', and they can go with quite a bang!
The only thing I'd add is when checking for rust, rust on the outside is not uncommon when the plating rubs off, this isn't a problem. Rust inside the can, however, is a problem and the can should be rejected - pay particular attention to the area of the side weld when the lacquer is thin. The contents, particularly if acidic (fruit juices), can eventually eat through the lacquer to the steel.
Also, don't store (unopened) cans in the fridge - the low temperatures can cause the latex in the seam to contract, its possible that this can cause the seam to leak, causing spoilage later.
That's a very sensible point, a hundred year old can of beans would be perfectly safe to eat provided the contents were still sterile, but the contents would be tasteless mush.mysterio wrote:It's my personal opinion that the fresher your brewing ingredients are, the better your beer will be.
However, like DaaB says, the extract will remain good for a long time after the 'use by' date - I've used kits which were 5+ years out of date, and have made excellent beer with them. If you're only talking months, or even a couple of years, out of date, I wouldn't hesitate to use them.