Brewing at Exceptional Altitudes? - revisited

Hey,

ran across an older thread when doing some research.

I can provide some insight on brewing at altitude ... our brewery is located in Leadville, CO @ 10156' above sea level! And there definitely are some challenges that come with altitude, all related to the reduced pressures in the environment.

1. Boil temp is 196F ... we have to formulate all recipes for a reduced boil-off rate, meaning less liquid during sparge. However, there are other factors affecting boil-off as well (surface area, volatility of boil).
2. Hops isomerisation will be quite a bit lower than sea level (~60%) however our brewing experience before opening was in Denver (~85% vs sea level). So, we need roughly 25% more boil time ... we run a 30 minute whirlpool with heat off, which seems to do the trick.
3. Because of the reduced pressure the break is much more volatile and needs to be managed. At first we were running a traditional 60 min boil and dropping hops @ 60. However Tim Matthews from Oskar Blues came through and helped us modify so that we run a 75 min boil and drop at 60. This allows us to get through the break and keep our hops in the beer and not stuck to the sides of the boil kettle.
4. And again in fermentation, pressure causes us some challenges ... when the yeast kicks in we get much more aggressive blow-off so we have to be careful about not overloading the fermenters or we will push the yeast out of the tank and into the blow-off bucket.
5. The last big challenge surrounds carbonation ... the general rule is to add 1 psi for every 2K feet in elevation change. Meaning we have to add 5 psi to the typical temperature-pressure chart. For most beer this means 13 - 15 PSI in the 32 - 34F range. That is manageable, however we serve our beer at 44F taking the pressure requirements to 18 PSI or a bit higher. Since bright tanks are typically rated to 15 PSI we serve only out of kegs currently and are working with an equipment maker to build us some 2 bar (29 psi) serving tanks.

Now you have all the secrets

Chris
www.periodicbrewing.com