Cross-section of the seam that holds the lid to the body of a beer can
With both the revamped Pyro and the new Roasted cans here at the brewery, we are gearing up for a week of hard core canning, which brings us to this edition of our Ask the Brewer question!
Ask the Brewer
How does the beer get into sealed cans anyway?
That is a good question. While our canning line is easily visible through the taproom window, and we have definitely had people working it while the taproom is open (do not taunt the brewhouse workers, they scare easily), it can still be hard to see (and understand) exactly what the process is.
One of the things that often surprises people is that the cans get shipped to us as open topped containers. The can body is separate from the lid, and the canning line fills and assembles them, seaming the lid onto the body. The picture above shows the cross section of a properly formed seam.
Canning beer can be broken down into 5 distinct steps that need to be performed properly to get a correctly filled, leak-proof can of beer:
- CO2 filling
- Beer filling
- Lid application
- First seam
- Second seam
Prior to being put on the canning line, each can is rinsed with a mild sanitizing solution to ensure that the beer is going into a clean container. Once placed on the canning line, the cans are moved forward in groups of three to the first operation of filling those cans with CO2. The CO2 is heavier than air, so it stays in the can, providing an oxygen free environment that maintains carbonation and inhibits flavor changes. The second step is filling the cans with beer. Again, the cans are moved forward until they are under the fill nozzles, which drop down into the bottom of each can. Beer flows from the brite tank to each of the three fill nozzles, into the cans and displaces the CO2, so that it is laying between the top of the beer and the rim of the can.
In the third step the canning line pushes the filled cans under the lid dispenser and into the seaming portion of the operations. The lid dispenser puts one lid on each can, trapping the bed of CO2 as well as the beer beneath it. The fourth and fifth steps are the actual sealing of the can, which is called double seaming. Each operation in the double seaming process needs to be precisely timed so that a tight and leak-proof seam is formed. The fourth operation consists of the curled edge of the cover getting interlocked with the flange of the can body. The fifth operation is the rolling and compression of those inter-locked edges. Correctly done, the end result is a hermetically sealed container.
Once filled and seamed, the cans are rinsed, removed from the canning line and snapped into four-pack holders. They are then placed into cases, put on pallets, and stored in our walk-in cooler for pick-up by the distributor.
Taproom Tidings
The first weekend of December continues our tradition of food on Friday and Saturday. Tollefson Family Pork Farms will be here with locally raised pork sausages accompanied by their made from scratch side offerings on both days.
We are open our regular hours, with growler and grumbler fills available all of the days we are open.
- Thirsty Thursdays are your chance for $1 off pints and $2 off growler fills (Remember, St. Paul doesn’t let us fill growlers after 8pm on Thursdays, so get here early)
- Whistler Soda has several new soda flavors, including a a caramelized pineapple and a mango soda.
- Tantalize your taste buds with a Gingerbread Custard Cupcake from Groundswell. Gingerbread with pumpkin custard and spiced whipped cream.
- Tap selection includes Pyro APA, Roasted Coffee Ale, Fused Orange Blossom Honey, Cranberry Shandy and Raj-Agni IPA, with the “brewer’s choice” of a Minnesota Mild also on tap.
Final Thoughts
If you are looking for that perfect gift for your beer loving recipient, give us a call or stop in. We have growler gift sets, shirts, hats and gift cards available in any denomination.
As always, if you have questions, drop us a note via Email, Facebook, North Pole Postal, Twitter or Google+.
Cheers!