Quality control for micro breweries

[boss429]

I just don't understand why SRM and hop profiles vary so significantly in the same beer brewed by the same brewery.

So as far as malt goes I have read this

http://morebeer.com/brewingtechniques/bmg/noonan.html

I have noticed malt profiles are commonly controlled but hop profiles are not. I wonder if the hop profiles vary generally because of human error or maybe the malt profile? Maybe the water profile affects it all as rain would change it (assuming no osmosis inverse..) Anyone have some input?

To prevent unnecessary confusion here are my following assumptions a brewery would have...

1) same grain supplier
2) same hop batch (year, grower)
3) a significant investment in QC (I'm not asking why the 2000bbl brewery or brewpub does not have QC...lol)

 

[WoodlandBrew]

Could you provide some more specifics on your initial question? It might be helpful to further answer your question. Which beer, and how far does the SRM color and IBU level vary? The little I know about how the big boys do it, from brewery tours and reading books, is that SRM is very closely monitored, and like you said, hops are purchased for a year in bulk and carefully analyses to ensure a consistent product.

 

[Beerrific]

One step in the process that has a very large impact on hop character (BUs, flavor/aroma; and SRM to perhaps a lesser extent) is the vigorousness of fermentation. If a brewery is not pitching a consistent amount of yeast, this could be an issue.

 

[ajdelange]

Obviously anything that changes from batch to batch has the potential to induce a change in the finished beer. With hops the obvious factor would be aging but another might be variations in humulone levels within a batch. How well was the lot mixed before the hop yard did the acid analysis? Water variations can have an effect on color and hops principle extraction and on the perception of hops bitterness.

Even the megabrewers who take QC to the ultimate don't get the same beer each time they brew. To make sure you get the same beer each time you buy they blend batches. I saw a video of this being done at AB. Here's a guy in an oak paneled room with about 30 bottles and glasses in front of him tasting all this and writing down instruction to blend so much of this gyle with so much of that. That man must have some palate. Among 30 samples of Bud light I doubt I could tell the difference.