[howie]

Wow, I didn’t know any micro brewer in the US had a mash filter. Alaskan also states that they are the first and there is a reason for that. For one, those filters are more expensive than mash tuns and more complicated to maintain. From what I read, and it may only apply to older models, there is more tannin extraction with the pulverized grist that commonly used with these systems.

In the Brewing Network discussion, they do mention that it was expensive, but they are saving something like 400,000lbs of grain a year and a million gallons of water per year as a result of the increased efficiency of this machine.  I'm guessing it would pay for itself VERY quickly with those kind of savings.

As others have said, they did it primarily to save in the cost and hassle of drying their grains after brewing.  They don't have anywhere locally to dispose of them, so they have to ship them off of the island.

Finally, they did address the tannin extraction/flavor issue. They basically said they did extensive testing with a demo model of the machine, and no one could tell any difference in the finished beer.

Sounds pretty awesome to me.

[dean]

I can't see a homebrewer doing it but for a brewery... if it saves them money and they can re-use something, why not?   

[Kaiser]

Despite their good efficiency, mash filters have not caught on in the industry. It may have to do with the increased tannin and lipid extraction that worries some brewers even if they may not be able to tell the difference. From what I read a modern mash filter can gain your about 1-2 % over a state of the art lauter tun. Using the 2% number I estimate that Alaskan uses about 20 million pounds of grain per year. If it takes about 10 lb to per gallon of their average beer that equates to an output of about 66,000 bbl per year which seems about right.

Kai

[Kaiser]

Back to the carbon thing. Given the current focus on carbon trading it seems that breweries might be able to generate some additional income by capturing and storing the excess CO2 from the brewing process. If they find an effective way to sequester it somewhere where it is not released into the atmosphere  they can start selling carbon offsets. Might not be worthwhile for most micros, but the big boys create enough CO2 for this to be a worthwhile exploration.

Kai

[MrNate]

The point I was trying to make is that even if you buy CO2 you are not adding any CO2 to the atmosphere since that CO2 has either been taken out of the atmosphere or is the byproduct of some other process (e.g. combustion) which was not allowed to go into the atmosphere yet. As I see it reclaiming CO2 in a brewery has only an economical benefit, but there is nothing wrong with that.

Kai

Kai has a good point here.

[rabid_dingo]

One question on the CO2 reclamation and purging tanks and what not....

Even if you manage to use the CO2 to pressurize the beer. Would it not be released into the atmosphere the moment
consumers open the beer at home? The idea that it would be pumped underground would be the only way that it would
actually be prevented from reaching the atmosphere. The idea that it was used in a later process in brewing only
re-allocates the release to a later time...No?  I would rather hear of breweries trying to calculate the amount of CO2 that
is consumed by plants and ensuring that that many plants were planted or growing on the property...

There are many many good ideas for the Green movement, but one has to take into consideration the actual footprint
of the idea before it can actually be considered green. Such as buying a used car is greener that buying a NEW hybrid.
Less impact to the environment if one keeps a car from going to a landfill as scraps from the metals that were harvested
prior to recycling the car as opposed to building a new car from all new material...

 

[BrewArk]

The ONLY way to be sure the CO₂ didn't seep out and make it's way to the atmosphere is to convert it into something else (carbohydrate & oxygen, or carbonate).

But that too would be difficult for a brewery.

As far as pressing the mash goes, I usually run out to the gravity I want, then put the rest into the compost.  The compost pile needs some water added from time to time anyway.

[brewboy]

Such as buying a used car is greener that buying a NEW hybrid.Less impact to the environment if one keeps a car from going to a landfill as scraps from the metals that were harvestedprior to recycling the car as opposed to building a new car from all new material.

I know this isn't the right forum, but that is right on target and what I was saying (actually yelling) the entire time the "Cash for clunkers" program was going on. Building new cars, causes pollution. Fixing up old cars makes more sense in so many ways.

And to keep it beer related, old cars can carry grain, hops, and yeast just as well as new ones. 

[abraxas]

As far as pressing the mash goes, I usually run out to the gravity I want, then put the rest into the compost.  The compost pile needs some water added from time to time anyway.

I need to watch the water in my basement compost bin or I tend to get some mold.  The air exchange is limited to prevent it from drying out too much between additions...

[Kaiser]

If you think about it, it could also be argued that Alaskan has a larger carbon footprint than most other brewers because the have to ship in all their raw materials (except water) and ship out most of their beer and their spent grain.

Kai

[MDixon]

Kai - I'm pretty sure I saw a plate and frame filter at one of the breweries in American Beer. For some reason I am thinking it was Long Trail.

While searching to see if it was LT (I still think it was), I noticed Full Sail uses one:
http://www.wendmag.com/greenery/2009/06/sustainable-craft-brewing/

I suspect it is much like breweries brewing with biodiesel, many more do it than we know.

[daubon]

On this topic I've pondered the idea of building a centrifuge to remove more liquid from the mash.  I figure that if this could be done one would need less sparge water and get better efficiency.  What do you guys think?  I may give this idea a try with our salad spinner to see what happens.

Thanks
Pepe

[Kaiser]

That’s a nice article. Thanks for pointing us to it.

I think the industry is definitely moving into the right direction but something should not be overlooked: the bigger a brewery is the more efficient it can brew beer. This was touched upon in the article but let me explain this a little more. If you are able to brew beer 24/7 you can easily use the heat you reclaim during chilling of one batch to heat the strike or sparge water for a subsequent batch. You can even reuse heat coming off the boil kettle by condensing or compressing the steam. But this only works if you brew all the time. Most small breweries neither have the equipment to do that nor do they have the fermentation capacity to handle the large amount of wort that is produced. They also lack the capital to afford the more sophisticated systems necessary and as a result a lot of energy is wasted by not efficiently using the hot water from the wort chiller or the need to run with 8-10% evaporation in the kettle.

When it comes to energy and water use per unit of beer produced, home brew is arguably the worst due to the simple equipment and constraints we are working with. It starts with the use of R/O water continues with 10+% boil off using fairly inefficient heat transfer between burner and kettle and finishes with the use of an immersion chiller to cool the wort.

What offsets this inefficiency that many small brewers have is the fact that they raise awareness of the importance of going green. Over time that will become part of the natural thinking of people and together with increased prices of energy and waste disposal it should bring down our overall dependency on fossil fuels.

Kai

[dbeechum]

If you are able to brew beer 24/7 you can easily use the heat

This was one of the two most impressive facts that I ran into when I toured the ABI plant in Van Nuys last year. Everywhere they can, they're capturing and redirecting heat. They take it from the chiller, the steam stacks, etc. Anything to save a few more joules and reduce water consumption.

The other was the fact that the brewing staff for the whole plant (which runs 24/7 and produces 250,000 barrels per month) was 6 folks per shift. 2 in the brewhouse, 2 in fermentation and 2 in packaging. Oh the electronic toys they have to make that happen.