Carbon Neutral Homebrewing?

[benkbenkbenk]

I sit of an evening in my living room, and I'm pleased to hear the occasion bubble and gurgle coming from my living room cupboard, safe in the knowledge that the wee yeasties are doing there job and converting all that sugar into alcohol and carbon dioxide (but most importantly delicious beer).

But it made me think, as I looked over the cupboard with my two house plants by the fireplace, how much CO2 is coming off, and are those two house plants sufficient to soak it up and churn back out lovely breathable O2?

So, how would one go about working out the amount of CO2 released during fermentation (I would have thought this would be possible from the OG and FG readings, plus a bit of maths) and how many houseplants do you need to balance it out?

 

[hairybiker]

I would think you should also consider the transport from farm -> you, for the malt etc.
But over all you would be about 10000% LESS than some one jetting off on holiday.

 

[chrig]

Its a decent lump. I seem to recall that around half of the sugars is converted to co2 the rest becomes alcohol. You could weigh it... I tend to find that a couple of pints of home few puts my mind at ease from the worry of my carbon. Footprint

 

[mattrickl06]

Nevermind the CO2 what about the 10kg/h of methane given off after 6 pints of oatmeal stout??

 

[PD]

Just think of the reductions you have made by brewing your own and the carbon footprint you have saved re transportation, packaging etc....

 

[Dr Mike]

The CO2 given off during fermentation is just returning part of what the grain absorbed whilst growing. The rest is returned when you metabolise the alcohol after drinking. So the CO2 offset is provided by the barley farmer growing this year's crop so no need for extra houseplants.

It's the same as any carbohydrate food. You breathe out the CO2 but that is balanced by growing fresh food. It's just part of the short term Carbon Cycle, unlike burning fossil fuels where we are re-emitting CO2 into the atmosphere that was previously locked away millions of years ago.

 

[TouLouseLePlot]

I did once work out the carbon offset involved in re-using a beer bottle 4 times a year for 10 years instead of making 39 of them and shipping them here from China.

All I can remember is you should be proud of saving the planet, virtually single handed.

 

[oldjiver]

As a vegetarian homebrewer you can probably hear my methane footprint some mornings. :sick:

 

[ericmark]

All the sugar will be converted to CO2 be it by yeast or yourself but since the sugar is grown in the first place it's the same as all other food and is carbon neutral. I was however surprised when full carbon cycle was pointed out to me for burning wood.

It clearly does matter how vegetation is broken down. Also of course transport. So beet sugar produced in UK will be more carbon neutral than cane sugar which is imported.

However saying that growing in rich UK soils can release carbon from the soil which would not be in soils of other parts of the world and just as the carbon cycle for burning wood was not as simple as I first thought so the same applies to food.

In natural woodland although some of the trees will rot some will be trapped and in the end turn into oil and coal in the same way of course putting rubbish in land fill will be trapping carbon and removing it from the cycle. Yet we are told to re-cycle.

I have found Tesco shopping bags degrade and turn into dust and one has to ask when there is a push to re-use shopping bags and a levy is charged for each bag used is the supply of bio-degradeable bags good or bad? At least in Wales!

As we start to look closer at the measures introduced so we start to wonder about the real effects. Tungsten light bulbs for example produce heat as well as light and most the heat is radiated heat which does not heat the air but acts directly on the person so the air temperature can be reduced. Since heat lost from the house is dependent on air temperature during times when the heating is on using tungsten bulbs and reducing the room temperature by 2 degrees would save energy plus the tungsten bulb does not contain mercury or other nasty things so can go direct into land fill.

The list goes on so I have come to the conclusion that all this so called energy saving is all down to making money and nothing to do with saving the planet. Rushing in to change things so often means we miss some vital fact. The NiCad battery was all the rage now banned except for medical and military use because they were found bad for the planet. The NiMh it would seem also cause problems with laptops and Boeing planes going on fire. What will happen to all those used in electric cars?

So I would not worry at all about the little CO2 coming off your beer. Yeast has as much right to live as all the other live forms on the planet.

 

[Rolfster]

+ 1 for what Dr Mike said (I was going to say something similar, but he had already said it, and better than I would have put it, probably!)

 

[calumscott]

It's not all that simple... but in terms of fermentation CO2 release, yes, that's catered for (and more) by the carbon fixing of the crop in the first place.

But.

Add into the mix the fuels at the various stages of the process of getting that malt to your fermenter and things don't look so rosy...

1) Fertiliser production
2) Irrigation
3) Crop tending machinery
4) Other chemical production
5) Transport Fuel (field to store, store to maltster, maltster to warehouser, warehouser to retailer, retailer to you).
6) Malting Fuel (germination, kilning)
7) Mashing Fuel
8) Boiling Fuel
9) Brewery water usage (washing and sterilising, brew water, bottling washing and sterilising, wort cooling etc)
10) Brewing chemical production (sterilisers, water treatments etc)
11) Other ingredients e.g. hops (all the growing, drying, transport packaging etc)
12) Packaging of malt, missed that...

There's probably a whole lot more... Aside from the reuse of lots of things (like bottles) we're actually a pretty inefficient bunch compared to a big brewery.

 

[Crastney]

I would be more worried about the amount of gas used heating 20 odd litres of water for a 90 minute boil, than the CO2 produced by the yeast.

one of the reasons that I've not started brewing ale is that boiling something so large for 90 minutes seems quite a waste of fuel, and then the water rushing through the chiller coil, that all goes down the drain - what a waste of all that potable water, and running fridges, and heaters to get their brew to the right temp. etc.

I prefer to make wines and ciders and infusions, which are just left to their own devices at whatever temp they happen to be at.

Maybe if I had solar panels, and brewed using the electricity from those on a really hot sunny day, that might be ok with me.

that's my opinion on the matter anyway.

 

[benkbenkbenk]

Wow, thanks for all the in-depth replies, a wealth of information there.

What about if you consider my living room as a closed system. People often put houseplants in their room, to oxegenate the air, so could the plants balance out the CO2 coming from the homebrew?

 

[Dr Mike]

Even in a closed system, the CO2 given off by the fermentation will likely be insignificant next to that which you and yours are exhaling. Also, unlike people and animals, the fermenter is not consuming oxygen (alcoholic fermentation being anaerobic).