Author Topic: Pressing the Mash  (Read 3618 times)

Offline abraxas

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Pressing the Mash
« on: March 11, 2010, 07:17:26 AM »
I have read online that pressing a mash is a bad idea because it can result in excessive tannin extraction from the grain.  Has this held up?  I have read a few conflicting opinions on this.

I know some commercial breweries press and then filter their mash between sparges http://www.alaskanbeer.com/our-brewery/sustainable-brewing/brewhouse-innovation.html

The downside to this seems like pressing the mash would result in messing up the natural filtration system that is the grain bed.

I am starting to think up a new rig, if I could press my mash I would think I would be able to design a two pot no-sparge rims system that would get decent enough efficiency.

Online Kaiser

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Re: Pressing the Mash
« Reply #1 on: March 11, 2010, 07:30:47 AM »
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.

Though I think that it may be possible for a home brewer to build a system that presses the mash it will be more complicated and more trouble than a conventional lauter system. In a mash filter you have a very large filter membrane area which results in a very thin (few cm) grain bed. I doubt that you will be getting good results by pressing the grain bed against the false bottom of a conventional lauter system.

Kai

Offline dean

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Re: Pressing the Mash
« Reply #2 on: March 11, 2010, 07:38:13 AM »
From what I could gather, the reason they do it is to save fuel/energy before they dry the spent grains prior to shipping them to farmers and ranchers.  They also are the first or only microbrewer to capture Co2.  Sounds like they are being very eco-friendly.

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Re: Pressing the Mash
« Reply #3 on: March 11, 2010, 07:49:57 AM »
Here is something else I found on their site that struck me as being a bit of BS:

Quote
CO2 recovery system

In 1998, Alaskan Brewing became the first craft brewery in the United States to install and operate a carbon dioxide (CO2) reclamation system. The system captures and cleans carbon dioxide, a natural byproduct of the brewing process, and uses it to package the beer and purge oxygen from holding tanks, saving money and the environment. This system prevents approximately 783,000 pounds of CO2, a greenhouse gas that contributes to global warming, from being released into the atmosphere each year. That is equivalent to preventing the emissions from using more than 40,000 gallons of gasoline annually.

Either way the CO2 will get in the atmosphere. Brewing produces CO2 and unless they capture it and put it underground it will get in the atmosphere. And it is not such that the external CO2, which they may have been using before, was made just for making CO2. It was either the byproduct of some other process or captured from the air and bottled.

I do believe that we have to reduce our CO2 footprint but I disapprove of statements that make the layman believe that they are actually reducing the release of CO2 to the atmosphere. It is however a good idea for a brewery to reclaim their CO2 just from an economical point of view.

Kai


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Re: Pressing the Mash
« Reply #4 on: March 11, 2010, 07:52:26 AM »
From what I could gather, the reason they do it is to save fuel/energy before they dry the spent grains prior to shipping them to farmers and ranchers.  They also are the first or only microbrewer to capture Co2.  Sounds like they are being very eco-friendly.

Yes the fact that the stabilize their grain before shipment made a compelling argument for a mash filter since the spent grain from those is already drier than convertional lauter tun spent grain. But that should not be reason why home brewers want to go that route.

As for the CO2, see my last post since I consider this a BS statement. What would reduce their carbon footprint is the use of a low evaporation boil system (Merlin for example) and/or extensive energy recycling in the brewery. Using the wort chiller to heat mash and sparge water, recapturing the heat from the steam coming off the boil and more.

Kai
« Last Edit: March 11, 2010, 07:56:56 AM by Kaiser »

Offline abraxas

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Re: Pressing the Mash
« Reply #5 on: March 11, 2010, 08:17:26 AM »
I press my grain anyways since I move it to my basement compost system but I generally discard the liquid as I have assumed it is too high in tannins.  I guess I will have to investigate this further next time.

Online hopfenundmalz

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Re: Pressing the Mash
« Reply #6 on: March 11, 2010, 08:47:14 AM »
I don't know who was first, but Sierra Nevada also captures the CO2, removes the esters and alcohol that comes out as vapor, and uses the CO2 in the brewery. 

Jeff Rankert
Ann Arbor Brewers Guild, AHA Member, BJCP Certified
Home-brewing, not just a hobby, it is a lifestyle!

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Re: Pressing the Mash
« Reply #7 on: March 11, 2010, 08:48:15 AM »
The problem of pressing grains is not necessarily tannins but unconverted starches. The latter can be released from the grain and may not be converted by the time you heat the wort to a boil. That can be checked with an iodine test though.

Kai

Offline Thirsty_Monk

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Re: Pressing the Mash
« Reply #8 on: March 11, 2010, 01:09:29 PM »
Brewing Network just had a show with Alaskan Brewing Co. and they talk about mash press.
You can listen it here:
http://thebrewingnetwork.com/shows/611

audio file is here:
http://www.thebrewingnetwork.com/membersarchive/dwnldarchive03-07-10.mp3
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Offline medicineman

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Re: Pressing the Mash
« Reply #9 on: March 11, 2010, 06:15:32 PM »
The point is that they reclaim and use the CO2 produced from fermentation rather than using new CO2 for packaging.  They do save CO2 by doing this.  It all ends up in the atmosphere but they aren't using as much.

Online Kaiser

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Re: Pressing the Mash
« Reply #10 on: March 11, 2010, 08:21:53 PM »
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

Offline dean

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Re: Pressing the Mash
« Reply #11 on: March 12, 2010, 04:48:37 AM »
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, have you been watching the history channel, I love watching scientist prove and disprove each other.... global warming.   ::)   :D  They just did a show on N.America's Ice Age, it was quite interesting.   ;)  A friend of mine was also talking about how some people still want to tax farmers for cattle farts being a major contributor to global warming also... I guess dinosaurs and whatnot didn't fart, they were ladies.   :D   ;)

Maybe a change in the topic, I don't know but has anyone tried brewing with snow?  The same friend I was talking about mentioned to me that snow has nitrogen in it... I suppose it would probably escape during the boil though?  I was thinking yeast need the FAN.
« Last Edit: March 12, 2010, 04:55:18 AM by dean »

Online Kaiser

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Re: Pressing the Mash
« Reply #12 on: March 12, 2010, 07:14:37 AM »
Kai, have you been watching the history channel, I love watching scientist prove and disprove each other.... global warming.   ::)

Don't get me wrong. I believe that global warming is fact and that we are mostly to blame for it. I just don't like it when prople jump on the band wagon of "carbon foot print reduction" when they are not actually reducing the carbon footprint. I leave it at that since this is not the pub.

Quote
Maybe a change in the topic, I don't know but has anyone tried brewing with snow?  The same friend I was talking about mentioned to me that snow has nitrogen in it... I suppose it would probably escape during the boil though?  I was thinking yeast need the FAN.

Brewing with snow is the same as brewing with rain water. Though it is very soft water it also contains all the pollutants you find in the air and as a result is gererally considered unsuiatble for brewing. It also takes quite a bit of energy to melt the snow.

Kai

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Re: Pressing the Mash
« Reply #13 on: March 12, 2010, 07:16:06 AM »
Kai, have you been watching the history channel, I love watching scientist prove and disprove each other.... global warming.   ::)

Don't get me wrong. I believe that global warming is fact and that we are mostly to blame for it. I just don't like it when prople jump on the band wagon of "carbon foot print reduction" when they are not actually reducing the carbon footprint. I leave it at that since this is not the pub.

I have similar comments to a past Zymurgy article about brewing green where some of the reduction of energy needed for brewing beer came from brewing less beer.

Quote
Maybe a change in the topic, I don't know but has anyone tried brewing with snow?  The same friend I was talking about mentioned to me that snow has nitrogen in it... I suppose it would probably escape during the boil though?  I was thinking yeast need the FAN.

Brewing with snow is the same as brewing with rain water. Though it is very soft water it also contains all the pollutants you find in the air and as a result is gererally considered unsuiatble for brewing. It also takes quite a bit of energy to melt the snow.

Kai

Offline dean

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Re: Pressing the Mash
« Reply #14 on: March 12, 2010, 07:34:14 AM »


Brewing with snow is the same as brewing with rain water. Though it is very soft water it also contains all the pollutants you find in the air and as a result is gererally considered unsuiatble for brewing. It also takes quite a bit of energy to melt the snow.

Kai

I don't doubt what you're saying but my friend knows quite a bit also being a farmer, according to him nitrogen is picked up in the stratosphere or one of the atmospheric layers at lower temperatures and stays with the snowflakes compared to the warmer temperatures of rain water.   ???  He says snow reduces the amount of nitrogen needed for fertilizer, winters having heavy snows produce a more nitrogen rich soil saving him money.