Our Carbon Footprint

PONDERING AN ASPECT OF OUR CARBON FOOTPRINT

R. E. Evans, a well-respected Brewer and Brewing scientist of the time, wrote a paper back in 1898 from which this segment is taken.  He referred to the English Brewing Industry.

“The amount of carbon dioxide produced by the brewing industry alone in a single year is enormous, nearly all of which goes to waste. It is the most important by-product of the brewer, who is in this respect more fortunate than most manufacturers, and being a compound so largely found in nature, it is perhaps doubtful if it would pay to collect.”

“Taking an average of 36 million barrels brewed every year of an original gravity of 1055 and attenuated to normal extent, this would give about 19 lbs. of carbon dioxide per barrel, or a total of 35,357 tons, all of which is let loose into the atmosphere to be again absorbed by various plants. This amount of gas is capable of giving out a certain amount of energy if liberated under pressure. One gram of carbon dioxide, liberated at a pressure of 75 lbs, per square inch and allowed to expand to atmospheric pressure, will give 56·404 foot-pounds of energy, and will then occupy a space of (at 20° C.) 544·4 c.c. Now, as 19 lbs. equal 8664 grams, a barrel of fermenting wort will give energy amounting to 488,649·6 foot-pounds, or, expressed in another way, sufficient force to lift 218·1 tons one foot.”

“Multiplying this by the total number of barrels brewed we obtain a potential energy capable of lifting 78,516,000 tons to the height of 100 feet, which would raise 12 pyramids the size of the great Pyramid of Cheops, which weighs over 6,000,000 tons, to the height of 100 feet. This amount of power directly and actually represents part (and only a small part) of the energy derived from the heat of the sun shining down on the green leaves of the barley, &c., in various parts of the world, but vast as this seems, it becomes small compared with the enormous quantity stored up by the sun in ages past in the form of coal, for the whole of the above amount of energy would be only equivalent to the consumption of 16,350 tons of coal, reckoning 4 lbs. of coal per indicated horse-power-hour.”

This represents beer brewing alone and only in Britain.  There are many other aspects of the fermentation industries which contribute to the output of CO₂ such as wine, spirits, and bread baking.

As for me, I don’t worry about leaving a carbon footprint . . . I drive everywhere.