Jeff,
During our workshops we advocate the use of 100% CO2 for those systems that temperature can be maintained at the keg and from the keg to the faucet. Normally direct draw systems only. In some cases we will even specify a blender for a direct draw. Particularly for a remote area. All other systems are specified with on site gas blending until the pressures are in the high 30's to 40's when pumps will then be recommended. Even with the pumps, we recommend propelling the kegs with an appropriate blend to take temperature out of play.
The only time 100% CO2 can be successful is when temperature can be maintained 24/7 at the keg and throughout the system. This limits it's application. Air shaft systems are notorious for temperature issues, not to mention the use of vinyl tubing. With this, we advocate the use of a gas blender, again with the application of the correct ratios, with the use of 1/4" or 5/16" ID barrier for trunk replacing the majority of vinyl. If this is not critical thinking, what is?
Think about all of the systems that Perlick has sold and installed successfully. We probably should define the word successfully. How many thousands used an air compressor? This is where we differentiate ourselves from the rest of the industry. We can design, provide, consult and install systems that dispense draught beer successfully from the keg to the glass - to strive for the lowest pour cost possible for the retailer and to encourage resale by maintaining quality.
Is there still room for improvement? Absolutely! We are aware of all the issues you present. We are also aware of the deficiencies in the industry as to knowledge transfer. This is why we are conducting numerous workshops at our facilities and at beer wholesalers across the country.
My mistake on the 70%. Although the 30% comment still stings. We don't profess to be chemists or engineers. Nor do we try to convey such detailed information so that techs can dispense beer on the moon! But we believe that today as well as in the future we will be on the leading edge as to dispensing draught beer successfully from keg to glass whether it will be a hundred systems or hopefully a few thousand.
Scott Zuhse, Instructor
Micro Matic Dispense Institute