This is where I will try to post, as often as I can, on beer topics that are related to my beer, the beer I drink, and my beer education.

Tuesday, March 21, 2006

Day 37, Trip to AB-Fairfield plant

We spent the morning discussing the stages of beer from "green beer" to packaging; which includes maturation, clarification, stabilization and carbonation.
The afternoon was devoted to our fieldtrip to the AB-Fairfield plant. The brewhouse was rather interesting, we were able to check out their brew kettles (700 barrel volume), mash tuns, rice cookers, and their new, enormous lauter tun (it took up half the space of the entire room). I was pleased to learn some of their strong environmental processes. Apparently they recycle or re-use over 98.7% of their waste and by-products. Their packaging plant was very impressive, producing 900 bottles per minute per line and 1500 cans per minute. Everything was a bit of a blur.
Krausening, which we learned about this morning, is a very interesting process. AB does this with beech wood chips. The beer goes through the primary fermentation stage in normal fashion. The secondary fermentation is performed in horizontal cylindrical tanks (I believe there were 120 x 1,750 barrel tanks). Inside these tanks the green beer is combined with 10 to 20% freshly fermenting wort and the tanks are filled up.
Since the AB yeast is a high producer of diacetyl, it is extremely important to allow the diacetyl reduction reactions to take place here in order to remove the diacetyl compounds. The main point of the beech wood chips is to provide more surface area for the yeast to flocculate onto. Coors also krausens their beer, but the process is slightly modified to avoid the use of the beech wood chips. The chips, as I saw today, are highly labor intensive, but AB currently views them as their only reasonable option to attain their goals. I had previously imagined the chips as tiny little things, about 1 cm x 1.5cm x .25cm. In reality, I was only right about the thickness being about .25cm, because they appear to be long strips of beech wood bark (though it is not predominately bark).

2 Comments:

Blogger Deez Nutz said...

mmmmm.... beachwood aged

8:41 AM

 
Blogger Andy said...

I would love to see how the big boys do it - I can imagine there's more to learn from them than most places, too. Just... less applicable. :)

10:02 PM

 

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