drying spent grains

[redlodge.sam]

we currently feed our spent mash to pigs. the pigs like the mash better when it is dry. any ideas on how to inexpensively dry spent mash?

thanks,
sam

[Diamond Knot]

Sam,

No kidding............I have a few questions.......
What's the size of your Brewery? 10Bbl? 15 Bbl? 50 Bbl?
What heats the kettle? Direct Fire Gas? Steam?

"The most inexpensive" method is to scavenge heat from the various heat sources in your brewhouse (hot water heater, brew kettle) and duct that dry heat under a false bottom with the grain on top. This is how our hops are dried, by the way.

However, the grain needs to be spread thin (about 3" - 5" thick) so that air will pass through, and have this hot air blown up through it. You could dry grains while you are boiling, and fan the heat up through a screen under the grains. You could also run hot water heater natural gas exhaust ducts up into the heat collector as well.

All of this is pretty exotic, and it depends on the size and waste energy output of your Brewery.

[redlodge.sam]

brian,

i have a 15 bbl direct fire brewhouse.

do you propose that i some how get the mash up to the exhaust stacks for drying? or can i capture the exhaust heat and bring it down to the floor where we shovel the mash into steel tubs?

thanks for the reply
sam

[Diamond Knot]

Sam,

It's ironic how topics come up. We were just talking about your situation in our Brewery with the thoughts of drying the mash for use in foods.

Thinking about it, I'm not sure you could cost effectively dry the mash in your facility. My thought is that you would have to tumble it as well and that would take time. I think that just passing hot air through teh spent grain bed probably wouldn't work as it does in hop drying...........the hops are a lot lighter, dryer to begin with, and allows for more air movement.

Somehow one would have to tumble the grains to expose more surface area to the hot air. However, scavenging heat off the brewkettle hot exhaust would be the best source. Hopefully, your burner is properly set and not producing a carbonizing flame. You could re-route the Clas B venting through a tumbler/dryer............it's hard to tell how without seeing your lay-out and process. However, tumbling 800 - 1100 lbs (dry.......wet weight?) of mash is no small feet. Routing the Class B venting and still maintaining an upward slope to the most conventient location for the dryer as well as not getting burrned on the venting could be design challenges.

[rudge75]

Just a side question if you don't mind:

How much are you getting from the farmers for your spent grain?

[redlodge.sam]

rudge75: we raise our own pigs north of town. in the past i've given it too cattle ranchers just to get it off my hands. its not all that hot a comodity around here.

diamond Knot: i've considered what you're talking about before, but it seems like it may turn into a never ending hassle setting it up. unfortunately (or maybe fortunately) ive got too many things to do to set up a dryer/tumbler system. thanks for teh insight though.

sam

[Sir Brewsalot]

I'm not an expert in the dietary preferences of pigs, but maybe it just needs to be a little drier, and not completely dry? (These animals do eat "slop", don't they?)

How about leaving the grain in the tun to drain overnight? Or, if that's too stinky, drill out the bottom of your spent grain receptacle (55gal drums in my case) and allow them to drain that way? Or maybe install a crude false bottom in it?

Scott

[damoller]

Can you not just turn on the steam to the jackets in the mash tun to dry? Should be dry in a short time

[Cargill Malt]

Unfortunately we don't have too much to add to this discussion as grain drying at this scale is not something we have a lot of experience with. The real experts in grain drying are the guys up at Alaskan Brewing Company. They've been drying all of their grain for years. If anybody knows somebody up there I'm sure they could be enlightening.

My gut feel is that if you have to add some apparatus for drying the grain the cost/effort/space required will kill the project. Some intermediate step like the draining spent grain buckets would probably be most feasible as long as BOD load in your waste water isn't a deal breaker.

Cargill

[banjo]

Here in Oregon we grow a lot of mint. And for years no one seemed to know what to do with the spent mint after pressing or the mint straw that had to be collected from the fields each year. Finally, not too many years ago, two markets were discovered and expanded for these previously worthless byproducts. Today I pay $13 for a yard of mint compost made from the spent mint (superior to bark for landscaping because it actually puts nutrients back into the soil, and it smells good too), and the mint straw is now bundled, sold, and shipped to Japan. Is it possible there is another market out there that could be developed to make a profit from spent grain?

[kerks28]

I was a brewer at Alaskan until very recently and I have to say that they did it right. Alaskan dries almost 24/7 and it takes a fair amount of fuel. They start the drier with diesel and then once it is hot (700F) they start adding dry grain to continue the fire. They utilize the heat off this 1500F fire through the use of a fan that pulls the hot air through a huge drum with many chambers in it. The wet grain is added to the drum and once it passes through (takes about 30 min) it is down to almost no moisture. Then we ship it back down south. You can see this is just one reason why it is expensive to brew in AK.
I imagine one could try to make a makeshift drum out of a 55 gallon drum and have a fan sucking hot air through it (from some sort of fire) and have the grain added at intervals into the drum. Although I imagine unless you had a burn chamber the heat loss would be too great. I don't think it would be economical in anyway to look at purchasing a grain dryer though. Sorry not much help.

[Ziggy-san]

I give about 200# of spent grain a week (not nearly as much as y'all) to a friend of mine who has pigs and horses. We cart it over and dry it on his roof by spreading it out about 2" thick on a tarp. He rakes it once and its dry in a day. If you have enough space (and brew-monke... sorry, assistants) it'd be cheaper than an air dryer.

[Gael]

We've been feeding our pigs spent grain for 6 years. Not only do we not dry it, we add spent yeast, ends of old kegs, fruit from our fruit beers, and anything else that lies around long enough. They like it wet, the wetter the better. What they reallydon't like is processed feed - especially hog pellets. Mind you, our pigs are on pasture, which may change their attitude to real food. As another note, we also feed wet grains to dairy cows and sheep, and they all eat them wet just fine. The only things we've noticed is that if the grains start to get stinky, only the pigs will eat them, and most of the animals prefer less roasted malts. So (I hate to change this to a farming list, but...) maybe you should vary the pigs diet a bit more, put them on pasture and add some other brewery by-products to the mix! They are a bit like humans, needing variety or they get bored and picky.

By the way, spent grain also composts beautifully, as long as it's turned regularly and preferably mixed with other, drier materials. Trub, for example, or uneaten hay/straw...

Nice to know that someone else is farming and brewing!

Rebecca

[banjo]

I've done a little research on another possible use for spent grains.
The fact that Alaskan brewing actually uses dried spent grain as a hog fuel to heat their drying system got me thinking. There are a lot of different factories out there that use hog fuels (wood chips, etc.) to heat their boliers or whatnot. Alaskan says they had the BTU value of their dried spent grain evaluated and gave me the following numbers - Brewers Dried Grain with 10% moisture has a net BTU value of 5,000 BTU/pound.
This is very close to the BTU value for wood chips. Perhaps it would be worthwhile checking with local manufacturers to see if they would be willing to buy your spent grains or at least haul them off for free.

[Cargill Malt]

Did they mention how many BTU's it takes to dry the grain in the first place? This would determine if burning the stuff makes sense from an energy standpoint.

There was a talk at the CBC the last time it was in Seattle looking at various ways to deal with brewery waste in an efficient manner. They suggested growing mushrooms in the spent grain. Apparently this not only gives the mushrooms a good growth medium, it also makes the spent grain more suitable for animal feed as it is broken down further in the process.

So if you have a mushroom farm around perhaps you could ask them if they were interested.

Cargill

[Ziggy-san]

I've used spent grain to grow mushrooms on a small scale and it is an AWESOME medium for fungi.

Hell, if you can't find a local mushroom farm, start growing them yourself! Gourmet mushrooms are a tidy business, and you've already got the means to sterilize the media (mashtun & BK no?). If you have a pub attached, thats even better!

Here are some sites that might be useful:

Cultivation & Information:
http://www.attra.org/attra-pub/mushroom.html http://counties.cce.cornell.edu/clinton/ag/forestry/mushrooms/Growing%20Gourmet%20Mushrooms%20bw.pdf

Potential customer for media:
http://www.fungi.com/front/intro/index.html

List of Farms:
http://www.mushroomcompany.com/farms/index.html

[Foodlink]

Dear Ziggy-san,

Just a small question: What mushrooms are you cultivating? Thanks.

Kind regards,

[Ziggy-san]

I've grown Oyster mushrooms, Portobellos\Criminis, Chantrelles and Champignons.

I've heard that its good for Cepes, Blewits, Boletus etc. but I haven't been able to secure any spores or mycaelium to see for myself. I imagine that you could use it with Shitakes and Maitakes (Hen of the Woods).

I've contemplated mixing it in with compost in the ground to establish some morel mycaelium, but as yet I don't have a good location.

[Foodlink]

Dear Ziggy-san,

Thanks very much for your reply. One more question: Have you ever tried H202 (hydrogene peroxite) to sterilze the medium ? If yes have you got experiences and can you elaborate on the use. Thanks very much.

"Using hydrogen peroxide instead of conventional pasteurization is a relatively recent innovation. A manual on this method and more information is available at www.mycomasters.com."

Best regards

[Ziggy-san]

Nah, I haven't given H2O2 a go. No real reason other than vague fears about it interfering with the capacity of the fungi to digest proteins.

For me, steam\heat sterilization is easy as I already have the mashtun and boil kettles established.

All I do is throw some straw in with the spent grain, add a couple of cups of old yeast as nutrient, sterilize the mix, cool it, innoculate it, and stuff it into sanitized small-medium garbage bags with holes poked through. Keep em in a dark, humidity and temp controlled area until the mycaelium is well established and then give them small, diffuse light for about two weeks.

Voila, fresh mushrooms with VERY low inputs!

Ziggy

[imabrewer]

To answer the question in an earlier post, we use about 4300 BTU's to dry one pound of spent wet grain at 75% moisture. Scott described our process already (Hi Scott). We use about half of the dried spent grains we produce to refuel our burner for some additional drying heat, but the burner still requires oil in addition to the dried grains to produce enough heat for the drying process and also to help the grains burn without smoke. The grain does burn very similar to wood chips and has about the same amount of waste ash as wood which is another waste stream we have to deal with. The dried grains which are below 10% have a BTU value of about 10,000 to 12,500 BTU per pound when burned. The system is not cheap to buy or operate and if you can send your malt to someone without drying I would highly encourage it, it is an added cost that is not easy to justify. We only do it because we can not get rid of the grain locally and have to ship it out.
Curtis
Alaskan Brewing

[banjo]

Drinking beer is good for the planet

Now there is another reason to enjoy that glass of cool beer on a hot summer evening. Enjoy a drink with an environmentally clean conscience - beer bran, a by-product of brewing beer from barley, can be used to clean polluted waters, New Scientist Magazine posted on August 5th, 2006.

Researchers at Kobe Pharmace-utical University in Japan have demonstrated that the bran adsorbs hazardous organic compounds including benzene and trichloroethylene (TCE) from chemical and industrial wastewater. The US National Academy of Sciences reported last week that there is growing evidence that TCE, used in adhesives and paint, can cause cancer. The Environmental Protection Agency is carrying out a new risk assessment of the chemical.

Companies commonly use filters made from activated carbon to remove pollutants from water. The dry, porous material has a large surface area, allowing it to trap large quantities of impurities. However, it is expensive and energy-consuming to produce, as it is made by heating coal to around 900 °C, says Atsuko Adachi.

[BelgianBrewer]

It's amazing that I am #22 posting a reply in order to make someone's pigs happy! :eek:

One comment on feeding yeast and spent grains to animals. In general the yeast has to be pasteurized before being fed to animals. Especially cattle does not support live yeast and there have been situations where cattle died from it.

I just wanted to add this... so this was a post on cattle... not pigs!

BelgianBrewer
www.sbmbrew.com

[Brewinfo]

I wonder if feeding the recovered hops after the brewing process could have the same beneficial effect...

RESEARCHERS INVESTIGATE HOPS FOR POULTRY
UNITED STATES: University of Arkansas scientists find the herb – normally used in beer production – is an effective substitute for antibiotic growth promoters.

University of Arkansas poultry scientists Dr. Susan Watkins and Dr. Park Waldroup have reported that hops, an herb used to impart a bitter taste in beer, can be an effective substitute for growth-promoting antibiotics in broilers.

Working with Lloyd Rigby, a hops chemist from Yakima, Wash., and John Segal, a leading grower of hops in Grandview, Wash., Watkins and Waldroup conducted a feeding trial in which broiler diets containing either ground hops or a growth-promoting antibiotic were compared. According to the results of study, the ground hops improved early growth rate of broiler chicks and reduced the overall feed needed to produce a pound of gain. Although the response from the addition of hops was not as great as that obtained from the antibiotic treatment, it was significantly greater than that of birds fed the control diet.

“Over the past several years, we have been exploring a number of alternative products for replacing antibiotics in broiler diets, including many herbs, spices, organic acids, and other similar products,” Waldroup said. “This is the first product we have found that resulted in performance improvement of this magnitude.”

Waldroup added that additional work is needed to determine how consistent the response to hops might be under more stringent growth conditions and any effects on the broiler meat.

“Many herbs and spices flavor poultry meat, and the fact that hops lend bitterness to beer might mean that it could possibly impart some off-flavors to poultry meat,” Waldroup explained. “We recognize hops primarily for their role in the brewing industry, and that is precisely the reason we felt that they might be beneficial in poultry feeds. They serve as an antimicrobial to keep beer from spoiling, and there are a number of U.S. patents relating to the use of hops as an antimicrobial for several food products.”

[Iso-Alpha]

I know we have talked about drying grain, pigs and mushrooms up to this point. but..
I really need some info about spent grain silos.

What type (stainless, steel, bolt together)works better?
pros, cons?
Know anyone wanting to get rid of an old grain silo?

We curently use hoppers and a farm truck and would love to keep the hoppers out of the brewery (flies).

Thanks for the help,

Walter

[banjo]

Not quite the same but relevant!

Brewer hops onto green power bandwagon
May 2, 2007
http://www.theage.com.au/news/National/Brewer-hops-onto-green-power-bandwagon/2007/05/02/1177788207202.html

A breakthrough project which turns beer wastewater into electricity has won a $140,000 grant from the Queensland government.
The project, a joint initiative between the University of Queensland's Advanced Wastewater Management Centre (AWMC) and Foster's, is believed to be the first of its kind in the world.
The technology works by creating a microbial fuel cell, which feeds continuously on the organics in the brewery wastewater, turning it into watts.
The process also produces clean water and renewable, or non-polluting, carbon dioxide.
AWMC director Professor Jurg Keller said there has been a shift in focus in wastewater management over the past few years from simply treating waste to recovering valuable resources such as water, energy and nutrients.
"Technology that can do this should be supported, therefore the decision by the Queensland government to support this project is a very important signal, both to universities and industry," Prof Keller said.
The team's work is also backed by a $1.3 million Australian Research Council grant in addition to on-site and financial support from Foster's.
A patent is pending for the technology, which is designed for small to medium operations and could be used across a number of food, beverage and manufacturing industries.
The Queensland government grant was made under the Sustainable Energy Innovation Fund.
© 2007 AAP

[Moonlight]

This is old news...I believe Sierra Nevada has been doing this for a year or so.

[ausbrewer1]

Drying is only a good option is you are prepared to go to all the trouble of drying/packaging/selling directly, would be best to contract that out.

Wet spent grains are quite suitable for pigs/cows as a high protein feed, but dont have any vitamins so should not be solely used. You could try adding some yeast that you no longer require to the mix.

[ausbrewer1]

This is old news...I believe Sierra Nevada has been doing this for a year or so.

Apparently microbial and biogas technology are two different things entirely, but I agree there are some distinct similarities.

[Brewinfo]

Very interesting and new twist on the problem...

http://www.rockymountainnews.com/news/2007/dec/14/beer-waste-brewing-fish-food/
Beer waste brewing fish food
Entrepreneurs bet water can become useful high protein
By Roger Fillion, Rocky Mountain News (Contact)
Friday, December 14, 2007

The popular Fat Tire Amber Ale has been heralded for its "toasty malty" flavor.
But the New Belgium Brewing Co. beer has another characteristic: It's a key ingredient in an environmentally friendly form of fish food.
Three Colorado entrepreneurs are wagering hundreds of thousands of dollars to convert the wastewater from New Belgium's brewing operations into a high-protein ingredient to feed farm-raised fish.
The trio and their Idaho Springs startup hope to usher in change to the booming business of fish farming, or aquaculture. Fish farming has taken off as the world's catch of wild fish has hit a plateau. Global fish consumption, meanwhile, is climbing.
Farm-raised species such as salmon and tilapia rely on other fish such as anchovies and menhaden, which are ground into fish meal.
"We can't support the growth of the aquaculture business using fish to feed fish," said Randy Swenson, CEO of Oberon FMR Inc. "The business we're in is fish meal replacement."
Global fish meal production has been relatively flat at around 6 million to 7 million metric tons a year in recent years. Aquaculture output, by contrast, has been climbing at an annual clip of 5-plus percent, to more than 48 million metric tons in 2005.
Oberon is teamed with the Colorado School of Mines and New Belgium to brew up its "fish meal replacement" at a pilot production plant at New Belgium in Fort Collins.
The pilot facility will feed and convert the protein-laden bacteria already swarming in New Belgium's brewing wastewater. The goal: to change that bacteria into a protein-rich biomass.
The resulting Jell-O-like goop will be dried into granules and added to fish feed, reducing the need for fish meal in the feed.
"You're taking what was previously a waste and turning it into fish food," said John Spear, assistant professor of environmental science and engineering at the Colorado School of Mines.
Spear noted the process could be duplicated with wastewater flowing from other food-related plants such as those making soy milk or jam.
Mines and Oberon landed a $1.1 million grant from the National Science Foundation in 2006 to help bankroll the effort and to try out the protein ingredient in Bangladesh, a key aquaculture country.
The NSF said the project aims to cut the "environmental impacts of a major and growing global economic activity" - aquaculture. The process, it added, "could be implemented in many countries around the world."
And while environmental alarm bells have been sounded over fish farming, Renee Sharp, senior analyst at the nonprofit Environmental Working Group, likes the idea of Oberon's product.
"It sounds potentially very interesting and potentially very helpful," Sharp said.
Forty-three percent of fish that people eat worldwide come from aquaculture, according to a 2006 report from the Food and Agriculture Organization of the United Nations. That's up from 9 percent in 1980.
The level of fish caught in the wild, by contrast, has been flat. The FAO said that leveling-off, combined with a growing world population and increasing per-capita demand for fish, "spells trouble."
The organization raised questions about whether aquaculture can fill the gap, in part because of doubts about future fish meal supplies.
Enter Oberon. Founded in 2001, Oberon was the pet project of two Mines graduate students: Seth Terry and Andy Logan. Swenson, the CEO, joined in 2005.
A $900,000 round of venture capital financing last summer from two funds - including one backed by Colorado Internet millionaire Jared Polis - helped Oberon in its bid to commercialize its technology.
"We thought they had a great package as a startup company," said David Tze, managing director of New York-based Aquacopia Venture Partners, which invested $566,000.
Tze said Oberon's product is different from those being developed by other companies, such as Norway's Aker BioMarine and Florida's Neptune Industries Inc.
"None of the other products are based on material that is ultimately thrown away," Tze said.
At New Belgium on a recent sunny morning, workers cut pipe and scaled a ladder to prepare a 9,200-gallon plastic tank for use as Oberon's production plant.
"We're going to be retrofitting what was a water tank into a biological reactor," said Oberon cofounder Seth Terry, vice president of operations.
New Belgium's wastewater lines will feed the tank.
"We'll house the population of bacteria in this tank," Terry added. "The key is controlling the conditions under which the bacteria are growing."
Using a proprietary process, the bacteria will be nurtured to promote the growth of more protein-laden bacteria. The protein-rich biomass that results will be separated out in a nearby 2,500-gallon tank and dried into granules in a dryer.
Oberon plans to start producing up to 100 pounds of the granules a day by February. The company wants to ramp up that output to 500 pounds a day by the third quarter 2008 and eventually build a much bigger facility.
In addition to the planned feeding trial in Bangladesh, Oberon expects to ship the product to fish-feed producers that will add the protein ingredient to their feed.
"This is test material," Terry said. "It will not go into any finished product at this point."
Company executives want to begin commercial sales as early as next summer.
For New Belgium, the Oberon facility represents an environmentally friendly way to process its wastewater. The brewer is known for its green initiatives.
"We were pretty much interested from the first conversations we had with Seth and his crew," said Brandon Weaver, in charge of New Belgium's water treatment.
Oberon FMR Inc.
* Headquarters: Idaho Springs
* Product: High-protein ingredient to feed farm-raised fish in an environmentally sustainable way
* Key input: Wastewater from New Belgium Brewing Co.'s brewery facilities
* Production: Up to 100 pounds of protein granules a day by February. Oberon wants to ramp up to 500 pounds a day by third quarter 2008.
* Key partner: Colorado School of Mines
* Funding sources: National Science Foundation and venture capital financing