Microbrew Variation

I've had the AleSmith Speedway Stout on several occasions out of the bottle and on tap. Each time it seems to be a little different. They've all been fantastic, but just different. This weekend I went to AleSmith and had some directly from their own shop and it had MUCH more coffee than other times I've had it.

I'm just curious what causes beers to vary so much? Is it time? Hazards of the distribution chain? Slight variation in the recipe to refine it?

AleSmith is obviously an excellent brewery and I'm sure they're doing everything they can to create the same beer every time. It's just been surprising that their best beer has been somewhat inconsistent.

Some breweries are constantly making changes in their recipes and even if they don't, the ingredients change a bit. It's easier for the big companies to be consistent because they can afford to test each shipment. Widmer uses a finely tuned mix of hops in most of their ales, which is one reason they are hard to duplicate at home.

Storage conditions matter, shipping conditions, length of storage.

Then there's the bottle vs. keg factor. I'd expect coffee to be much more pronounced in a fresh keg.

The Swanson Effect in the food industry is the art of slightly changing your recipe so people don't get bored. They think they are eating the same item, but it isn't exactly the same on purpose.

Eventually, you get to the point where you can identify what changes were made in a batch.