Energy Use in Mead Production
Making craft mead uses a tiny fraction of the energy that craft beer uses to produce the same pint of alcohol. For people looking to reduce the carbon footprint of their beverage, mead and craft cider are both excellent choices.
In this section, we focus on Scope 1 energy inputs in three areas: Brew Day, Fermentation Cycle, and Chilling for Packaging.
Click on each term to learn about the impact of our honey sourcing, temperature stabilization, and packaging for a more robust image of the energy inputs throughout our supply chain.
In this section, we focus on Scope 1 energy inputs in three areas: Brew Day, Fermentation Cycle, and Chilling for Packaging.
Click on each term to learn about the impact of our honey sourcing, temperature stabilization, and packaging for a more robust image of the energy inputs throughout our supply chain.
A Quick Note about Beer, First
There is no real way to get around the total energy inputs for brewing beer. Mashing, boiling, chilling, and cooling all take a certain amount of thermal load.
Some meaderies perform a few of these steps (boiling, chilling, and cooling), but never all of them. In that way, it can be a bit like comparing apples and oranges. Furthermore, many breweries go out of their way to minimize their impact.
Breweries like Sierra Nevada, The Alchemist, 14th Star, and many more get a portion or all of their power from solar. Others like Hermit Thrush use renewable pellet boilers for their mashing and boiling.
Much of the energy cost associated with craft beverages is actually in other parts of the supply chain. Our temperature stabilization, for example, actually saves more energy than the entire thermal savings from brewing mead versus beer.
The reason we break out a Scope 1 for our products is that it's the area that we have the most control over, and it's easy for a lot of consumers to wrap their heads around. It also is the most germane analysis for homebrewers, so we did the work as part of our open source policy.
Some meaderies perform a few of these steps (boiling, chilling, and cooling), but never all of them. In that way, it can be a bit like comparing apples and oranges. Furthermore, many breweries go out of their way to minimize their impact.
Breweries like Sierra Nevada, The Alchemist, 14th Star, and many more get a portion or all of their power from solar. Others like Hermit Thrush use renewable pellet boilers for their mashing and boiling.
Much of the energy cost associated with craft beverages is actually in other parts of the supply chain. Our temperature stabilization, for example, actually saves more energy than the entire thermal savings from brewing mead versus beer.
The reason we break out a Scope 1 for our products is that it's the area that we have the most control over, and it's easy for a lot of consumers to wrap their heads around. It also is the most germane analysis for homebrewers, so we did the work as part of our open source policy.
What is a Scope 1 analysis?
Scope 1 means that we're looking at the energy input for the production of mead once all of the supplies have come into the meadery and before the product leaves the building. It does not include energy inputs to harvest the honey, transport the packaging, smelt the aluminum, and so on.
While those energy inputs are dealt with on other pages (see above), a Scope 1 is the only level of analysis within our means at present. For an excellent Scope 2 study for the brewing industry, please visit The Cradle to Grave Analysis by New Belgium Brewing.
While those energy inputs are dealt with on other pages (see above), a Scope 1 is the only level of analysis within our means at present. For an excellent Scope 2 study for the brewing industry, please visit The Cradle to Grave Analysis by New Belgium Brewing.
What is your production energy use?
Meadmaking requires almost no heating and minimal cooling throughout its production cycle. On brew day, we raise the temperature of our water by approximately 30 degrees Fahrenheit with an on-demand water heater so that our honey and water will mix.
By comparison, beer requires a protracted mashing period at 160°F (usually an hour), then boiling for an additional hour or more. The energy input for this process is 17 times higher than our energy input.
At this point, the beer must be returned to 75 degrees or so for fermentation to begin. This either uses water as a cooling agent which (in some cases) can be captured for additional brewing purposes, or an energy-intensive glycol cooling system. These numbers are not included in our comparison because practices vary so dramatically between breweries.
Luckily, the fact remains that the energy to heat water remains the same everywhere. (More on this later.)
To put it simply, you can produce about 16 cans of mead for 1 can of craft beer based on brew-day energy use.
By comparison, beer requires a protracted mashing period at 160°F (usually an hour), then boiling for an additional hour or more. The energy input for this process is 17 times higher than our energy input.
At this point, the beer must be returned to 75 degrees or so for fermentation to begin. This either uses water as a cooling agent which (in some cases) can be captured for additional brewing purposes, or an energy-intensive glycol cooling system. These numbers are not included in our comparison because practices vary so dramatically between breweries.
Luckily, the fact remains that the energy to heat water remains the same everywhere. (More on this later.)
To put it simply, you can produce about 16 cans of mead for 1 can of craft beer based on brew-day energy use.
What is your fermentation energy use?
This is where things get a little tricky.
Mead generates less heat during fermentation than some other fermented beverages due to the metabolic rate of the strain of yeast which we use. This means that we have a lower cooling load during production than many beers. We further support this by batching our power usage into off-peak hours, increasing the efficiency of our chilling system. To learn more about this, visit our page about heat recovery.
Some of these energy savings are offset, however, by our system of using continuous pump-over to assist the yeast in a healthy, speedy fermentation. To put it another way, the fermentation completes much more quickly thanks to continuously running pumps (which of course reduces life-span cooling loads), but the pumps themselves require energy to run.
We have the most efficient three-phase pumps you can get, but as electricians say, "on is always more expensive than off."
Mead generates less heat during fermentation than some other fermented beverages due to the metabolic rate of the strain of yeast which we use. This means that we have a lower cooling load during production than many beers. We further support this by batching our power usage into off-peak hours, increasing the efficiency of our chilling system. To learn more about this, visit our page about heat recovery.
Some of these energy savings are offset, however, by our system of using continuous pump-over to assist the yeast in a healthy, speedy fermentation. To put it another way, the fermentation completes much more quickly thanks to continuously running pumps (which of course reduces life-span cooling loads), but the pumps themselves require energy to run.
We have the most efficient three-phase pumps you can get, but as electricians say, "on is always more expensive than off."
What is your final chilling load for packaging like?
Thanks to aspects of our production (such as promoting cloudy meads), we have a very short chilling period compared to most breweries. In fact, we can chill and carbonate 2,000 gallons of mead in a single off-peak cycle (which, in Vermont, lasts from 10 PM to 6 AM). More on the impact of off peak usage in the page about heat recovery.
All carbonated beverages must be packaged cold, so eliminating this chilling phase is not an option.
The amount of power used by a glycol cooling system to chill liquids is extremely complicated to calculate. While it always takes the same amount of energy from a Newtonian perspective, the insulation of the lines, the size of the compressor, the insulation of the tanks, the outdoor air temperature, and a host of other factors come into play.
Since much of this is covered on the page about heat recovery, suffice it to say that keeping something cold for one day uses substantially less energy than keeping it cold for several days.
All carbonated beverages must be packaged cold, so eliminating this chilling phase is not an option.
The amount of power used by a glycol cooling system to chill liquids is extremely complicated to calculate. While it always takes the same amount of energy from a Newtonian perspective, the insulation of the lines, the size of the compressor, the insulation of the tanks, the outdoor air temperature, and a host of other factors come into play.
Since much of this is covered on the page about heat recovery, suffice it to say that keeping something cold for one day uses substantially less energy than keeping it cold for several days.
So what are your actual energy comparisons?
Due to the low initial energy input as well as the efficiency of our chilling, we estimate that holding everything else equal (similar packaging, similar canning line, etc.) the energy used in our facility to produce and package our mead is approximately 4% of a beer brewery.
Again, to use some simple math: We can produce an entire case of mead with the same energy used to make one can of beer.
Again, to use some simple math: We can produce an entire case of mead with the same energy used to make one can of beer.
The math behind the calculations.
The following report comes from an applied mathematics intern, named Hannah, who helped us gather data for the Drink Your Values Project. It's all her original notation, so it's not as linear as some reports might be, but it is very robust.
Initial assumptions/notes:
We're assuming a perfectly efficient system, (meaning that insulation isn't taken into account).
It takes 2.37 kW to boil off one gallon of water per hour at sea level.
The street temperature of water is assumed to be 68 degrees Fahrenheit.
Beer
Water is lost throughout the beer making process. About 1.7 gallons of water are used to make one gallon of a standard pale ale and significantly more for IPAs, closer to 2.2 gallons per gallon of final product.
For a Pale Ale, approximately 0.3 gallons are boiled off, 0.25 gallons are lost in the grain, and 0.05 gallons are lost to shrinkage. This leaves about a gallon of water, which makes up the majority of the beer’s volume.
Beer requires energy for both the mash and boil steps. First, water must be heated from the street temperature to the mash temperature, and then the temperature must be maintained. For a one-gallon batch of beer, 0.39 kW is needed for the mash step.
Then, the temperature must be raised to the boil temperature. This requires 0.1 kW for a one-gallon batch of beer.
Finally, the batch must be boiled for an hour. This requires 0.48 kW.
Assuming a well-insulated system, it takes 0.97 kW to make one gallon of Pale Ale.
Mead
The brewing process is much different for mead than it is for beer. There are no mash and boil steps. Water is heated so that the yeast will become active and ferment the sugars in the honey. No water is lost, and volume is added because of the honey, so the amount of water used is less than the amount of mead created.
One gallon of mead is about 0.85 gallons of water and 0.15 gallons of honey.
The process of mead making only requires water to be heated to 98 degrees Fahrenheit. In the Groennfell facility, it takes 0.07 kw to bring a gallon of water from 68 to 98 degrees. Thus, it takes 0.06 kW to heat the water needed to make one gallon of mead.
We're assuming a perfectly efficient system, (meaning that insulation isn't taken into account).
It takes 2.37 kW to boil off one gallon of water per hour at sea level.
The street temperature of water is assumed to be 68 degrees Fahrenheit.
Beer
Water is lost throughout the beer making process. About 1.7 gallons of water are used to make one gallon of a standard pale ale and significantly more for IPAs, closer to 2.2 gallons per gallon of final product.
For a Pale Ale, approximately 0.3 gallons are boiled off, 0.25 gallons are lost in the grain, and 0.05 gallons are lost to shrinkage. This leaves about a gallon of water, which makes up the majority of the beer’s volume.
Beer requires energy for both the mash and boil steps. First, water must be heated from the street temperature to the mash temperature, and then the temperature must be maintained. For a one-gallon batch of beer, 0.39 kW is needed for the mash step.
Then, the temperature must be raised to the boil temperature. This requires 0.1 kW for a one-gallon batch of beer.
Finally, the batch must be boiled for an hour. This requires 0.48 kW.
Assuming a well-insulated system, it takes 0.97 kW to make one gallon of Pale Ale.
Mead
The brewing process is much different for mead than it is for beer. There are no mash and boil steps. Water is heated so that the yeast will become active and ferment the sugars in the honey. No water is lost, and volume is added because of the honey, so the amount of water used is less than the amount of mead created.
One gallon of mead is about 0.85 gallons of water and 0.15 gallons of honey.
The process of mead making only requires water to be heated to 98 degrees Fahrenheit. In the Groennfell facility, it takes 0.07 kw to bring a gallon of water from 68 to 98 degrees. Thus, it takes 0.06 kW to heat the water needed to make one gallon of mead.
