How to Culture Bell's House Yeast: culturing yeast from a commercial bottle

Bell's Brewery (in Kalamazoo, MI) is one of Michigan's largest and most successful breweries. Their two flagship beers, Oberon and Two Hearted Ale, are two of the highest rated beers in the country. Bells uses a proprietary yeast strain for their ales that is not available for homebrewers. In my opinion, Bell's Brewery produces very simple beers, but their house yeast creates an interesting, unique final product. So, in order to use their yeast in my homebrews, I need to go straight to the source.  Fortunately for homebrewers, Bell's does not filter their ales, therefore making it possible for to culture their yeast from their bottles.


Ingredients:

• 4 bottles of Bell's Oberon (Bell's Pale Ale, Bell's Brown Ale, or any Bell's ale will work too)
• 1000 mL Flask
• 2000 mL Flask
• 1 lbs. Light DME
• Stir Plate

Directions:

**There are many ways to sanitize brewing equipment. Therefore, I will not go into detail on sanitation. All equipment must be sanitized during this process. Infected yeast starter = infected beer.

1600 mL yeast starter,
48 hours into fermentation

1. Buy Bell's Oberon and let it sit in the refrigerator for 2+ weeks. Wait until the beer looks clear and there is an obvious layer of sediment on the bottom of each bottle.
2. Make a yeast starter. 400 mL of water + 22 grams of DME will give you a gravity around 1.020. Boil for 10-15 minutes, cover with sanitized tin foil, and cool it down in an ice bath until wort is under 70 degrees F.
3. Pour out the majority of the beer in the four Bell's Oberon bottles, only leaving the bottom sediment.
4. Pour the dregs (bottom sediment) of four Bell's Oberon into the 400 mL starter and cover with sanitized tin foil.
5. Leave on stir plate for 48 hours.
6. Make a second yeast starter. 1200 mL of water + 142 grams of DME will give you a gravity around 1.045. Boil for 10-15 minutes, cover with sanitized tin foil, and cool it down in an ice bath until wort is under 70 degrees F.
7. Add original 400 mL starter with yeast to the 1200 mL starter. This should bring the gravity down to just under 1.040, for the entire 1600 mL. Place on stir plate for 4-5 days. 
8. Place yeast starter in a refrigerator for 7 days. Once the yeast has dropped to the bottom of the flask, decant the beer and store in a 250mL flask, mason jar, or any sanitized container for future brewing.
9. This process will give you approximately 50 mL of healthy yeast. You can use MrMalty.com's pitching rate calculator to figure out what size yeast starter you will need for your beer.

Resources:
How to: Culture Bell's house yeast - Bell's Homebrew Blog
Yeast Culturing from Bottles: Techniques - BYO
Yeast From Commercial Beers - John Palmer