I bought a can of Coopers Real Ale and started it yesterday with 1.5lbs of Muntons Plain DME and 1lb of corn sugar. I did not know it was past the Best By date till after I had the can half open. I went ahead and finished putting the kit together, also I used the dry yeast it came with. It took off in about 6 hours of the pitch and is going well with nice foam filling the bucket now. I think it will turn out fine, but was checking what everyone else thought about using an old can. The date was for 02/04/2011 on the can and the day of brew was 04/30/2011 so it is not to far past date. Next time I buy a can of LME I will look at the bottom of it first.