When discussing the Olde Mecklenburg Brewery’s upgraded back-of-house equipment, everyone tends to focus on the same stuff: all things steel. To be fair, it’s nigh impossible for the biergarten crowd to overlook the upgraded 60-barrel brewhouse looming through its glass-walled enclosure, and a plethora of fermenters and conditioning tanks tower over tour-takers.
Hiding behind all the glitz and glamour of stainless steel, there’s a largely overlooked and criminally unsung piece of equipment that’s been unceremoniously chugging away since the brewery relocated in August 2014. In an industry that is almost synonymous with carbon dioxide production, this system allows OMB to lower their emissions by capturing nitrogen right out of the air we breathe.
Beer has three main enemies: heat, light, and oxygen. OMB’s mantra of “always cold, never old” is a way of life for the delivery and sales staff, and their diligence addresses that first item rather well. Keeping their beer in kegs, or brown bottles with high-walled six-pack-holders, covers the second.
So, let’s talk gas. (I’ll keep this high-level, or we’ll be here all day.)
When beer is exposed to oxygen, it degrades in an unpleasant way. Imagine buying a six-pack, opening a bottle, and then tearing off a piece of the cardboard packaging and chewing on it instead of drinking the actual beer.
When a brewer transfers beer from a fermenter to a conditioning tank, it can’t simply be pumped over lest it come into contact with oxygen. Instead, it’s “pushed” over with a gas (usually carbon dioxide). Likewise, the awaiting conditioning tank must be devoid of damaging oxygen, so that destination tank is similarly purged (also usually with carbon dioxide).
Doesn’t seem environmentally friendly, does it? Also, consider that the carbon dioxide itself comes from tanks that must be refilled, with additional gas being trucked over regularly which further adds to the carbon cost.
That’s where OMB’s nitrogen-capturing system comes in. Thanks to a series of membranes, the unit essentially inhales surrounding air, and retains only compressed Nitrogen at a 99.995% purity rate.
Considering our air is mostly nitrogen (78% by volume), there’s an abundance to use. Nitrogen gas also doesn’t damage or otherwise influence the beer during transit between tanks, making it ideal for the task. When the transfer is complete, the gas is simply vented back into the very air where it came from. Mission accomplished.
Head brewer Carey Savoy’s done the math. By simply using nitrogen gas to push beer between the fermenters and lager tanks, it’s saving the brewery $5,300 a year, adding up to 16 tons of CO2.
Anyone who’s visited OMB, and either parked in the largely-forested lot or sat underneath the large biergarten trees, can see that the brewery has their surrounding environment in mind. Less visibly, all 12-ounce bottles that they fill are sourced from Wilson, NC, versus out-of-state, which further diminishes the brewery’s carbon footprint.
Olde Mecklenburg’s nitrogen-capturing system might not be much to look at; it’s just an awkward boxy unit with a pair of compressed air tanks attached. But this isn’t a system built for fashion, but pure function. It does a commendable job of allowing the brewery to cleanly and efficiently transfer beer while minimizing carbon dioxide emissions, and OMB couldn’t be more pleased with the results.