The Firkin Checklist

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  • Clean the firkin with PBW or other caustic.
  • Rinse the firkin.
  • Sanitize the firkin.
  • Insert the keystone bung into the keystone bunghole.
  • Syphon beer from your primary into the large bunghole (the one in the center).
  • If the beer has little to no residual sugar, about 6.5 ounces of dextrose corn sugar will lightly carbonate a 10.8 US gallon firkin.
  • Fill the cask all the way and remember to use a fining of your choice (gelatin or isinglass work well).
  • If a dry-hop bag is added to the cask, try to add a large, sanitized piece of stainless steel to the bag to make it sink a bit and not clog the top bung later.
  • Seal the cask with the large plastic bung.
  • High-gravity beers can condition at 55-65 degrees F for weeks or months.
  • A 5% ABV ale should be ready to soft spile in 7-10 days or less.
  • When you think the beer has conditioned and built up some carbonation, set it up level and horizontally on its wooden platform (stillage) with the large, center bung up. Keep the cask in horizontal stillage for a few days as close to 50-55 degrees F as you can.
  • One to two days before serving, hammer in a dry SOFT spile through the middle depression on the large, center bung of the cask. Beer and gas should escape through the soft spile. This is done to check the amount of carbonation and allow excess gas to be vented slowly (so not to dredge up sediment).
  • When the venting slows, wipe off the soft spile. When it takes three seconds or longer for beer to flow back through the spile, this means the cask is probably ready for a hard spile.
  • With ALL spiles, leave the top one-third of the spile showing out of the bung so you will be able to grab the spile with pliers when it’s time to remove it.
  • If you have plenty of time, sometimes it works just as well to skip the soft spile and go ahead and hammer in a hard, wooden spile 3-4 days before serving.
  • Wooden hard spiles will SLOWLY vent excess gas over 1-2 days. Replace hard spiles that become really soaked through.).
  • Remove the soft spile SLOWLY with a set of pliers. If you feel pressure begin to push up the spile, be ready with your mallet and another soft spile. Hop bags and yeast can sometimes clog the soft spile and make it look like the carbon dioxide is done venting. Often you will have a stream of beer come out when the soft spile is removed.  If so, quickly hammer in another soft spile and keep watching the venting – you may have to use 2-3 soft spiles (or more) to get to the correct level of carbonation. It always helps to have a towel ready.
  • When you remove the soft spile and only get a puff of gas (little to no beer venting from the cask), hammer in a hard spile (again, only two-thirds of the way in so you can pull it out later). Some hard spiles will still vent a tiny amount over time – this is OK – if the hard spile gets really soaked, pull out the hard spile and replace it with another.
  • Hammer in your sanitized serving tap (into the middle of the sealed, smaller bung at the end of the cask) a few hours before you are ready to start serving. Be sure the tap is closed when you hammer it in and the hard spile is in place.
  • If you must move the cask a short distance from the stillage area to the serving area, do so very gently, keep it level, and then give the cask a few hours to settle. NEVER shake, roll, up-right or jostle a cask before serving.
  • The cask should really be kept around 50-55 degrees F for the entire serving time. Cask ale served at room temperature does NOT last long and is NOT usually very pleasant.
  • When you are ready to serve, pour some beer into a glass to test the internal pressure of the cask. When the beer flows very slowly into the glass, remove the hard spile with pliers, place a damp towel over the top of the cask (to cover the empty spile hole and keep the cask cool), and start serving from the tap.  Never draw beer through the tap with a spile in the cask.
  • Please remember that putting filtered bright beer with CO2 into a cask doesn’t constitute cask ale. All cask ales should be placed into casks unfiltered with a little residual sugar and yeast to naturally carbonate the beer in the cask. All cask ales should have sediment. If a cask is rolled out, immediately tapped, and pours clear, it is not real cask ale.
  • Give cask ales plenty of time to drop bright and form the sediment layer. Don’t rush things.
  • Use good finings – isinglass, gelatin, etc., and condition casks at cool temperatures (50-60 degrees F). Warm conditioning temps make for exploding casks. Cask ales can’t be shipped in warm months on non-refrigerated trucks.
  • Cask ale can’t be delivered and served the same day. Please never do this. A cask should have at least 24-48 hours in very cool horizontal stillage position before being served. If you cask arrives the day of tapping, immediately set the cask in cool stillage position, and put the tapping off until the next day or next week. This is better than serving murky beer.
  • Casks should never be up-righted or jostled prior to serving. Stable stillage position is important.
  • Don’t soft spile just a few minutes before trying to serve. This often is not enough time. Vigorous soft spiling also dredges up sediment and makes the beer cloudy.
  • Remove both bungs and clean the firkin for the next time.
  • Return the firkin to: ________________________________________________


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