Re-Brewing with Spent Grains?

[Elijah Hutchinson]

Hi, my name is Elijah Hutchinson and I'm new to the forum. I was wondering if anyone had ever heard of re-using spent grains (perhaps through sparging?) to brew a very low abv beer (malted grain from all-grain brews). I remember reading a while back about monks having a tradition of doing something like this. Not quite the same as a "small beer" of colonial times. Has anyone ever tried anything like this? Would you need to add a little bit of adjunct sugar like brown sugar or something? The man in this video I found also mentions it. Any input or tips would be greatly appreciated.

 

[MaxStout]

Look into partigyle brewing.

 

[Elijah Hutchinson]

Look into partigyle brewing.

Thank you. That's awesome.

 

[SleepyCreekBrews]

that's a crime, and you WILL get busted

Seriously, if you're planning on mashing again , you'll need to add some additional base malt unless you don't mash out, but either way it's likely gonna be a pale and skinny beer.

 

[Jwin]

Helps to reserve a bit of the first runnings of the first beer for the second.
I do it all the time.
You'll need a bigger tun.

 

[Elijah Hutchinson]

Thanks you guys for your help. Is it best to add some sort of adjunct to the second runnings of wort to boost the gravity or does that yield bad results in your experience?

 

[AZCoolerBrewer]

I have wanted to try partigyle brewing for a long time. My understanding is that you make two beers, a big 8% ABV or more beer and a small 4% or less beer. Of course there’s no rule how big or small you make them but from what I’ve read and some initial recipes that I worked up, that is the range they tend to end up in. The idea is to make your big beer full volume no sparge. Then sparge into a separate kettle. The thick heavy wort will become the big beer. The thin light sparged wort is your small beer. If I was to add adjuncts it would be to the big beer not the small one. I would be afraid of disrupting the delicate flavor of my small beer and turn it hot with adjuncts.

 

[stz]

Two thirds of your extract is within the first third of your run off as a rule of thumb. Traditional methods involved no sparge so they'd run off almost the whole volume then run in more water, stir and collect the whole volume again for the small beer. In effect this is just like a single batch sparge without combining the runnings so just build your recipes with that in mind. The modern definition of spent grains involving a continuous sparge is very different.

 

[Elijah Hutchinson]

I have wanted to try partigyle brewing for a long time. My understanding is that you make two beers, a big 8% ABV or more beer and a small 4% or less beer. Of course there’s no rule how big or small you make them but from what I’ve read and some initial recipes that I worked up, that is the range they tend to end up in. The idea is to make your big beer full volume no sparge. Then sparge into a separate kettle. The thick heavy wort will become the big beer. The thin light sparged wort is your small beer. If I was to add adjuncts it would be to the big beer not the small one. I would be afraid of disrupting the delicate flavor of my small beer and turn it hot with adjuncts.

Great point about the adjuncts. I'm thinking the hop addition should be pretty minimal also. Maybe just adding a small quantity of hops at the end of the boil for flavor and aroma?

 

[madscientist451]

It depends how spent your spent grains are. Sometimes I'll take a sample of my final runnings and chill it down in a ice bath then take a gravity reading. If its 1.030 or so, maybe I'll run another 2 gallons of water though the mash, recirculating a few times. Usually end up with a 1.020 wort. I'll then boil it and make an experimental batch, maybe adding some extract, maybe use some homegrown hops, or just make a weak wort with no hops for a yeast starter. I've made some decent "small brews" and drain pours as well. I recently made a "garbage beer" with seccond runnings from the mash, apple peels from a large amount of apple sauce I made, and whole leaf late addition hops from the bottom of the kettle from a previous beer.
It wasn't bad except I used too much hops and it is too bitter/too much hop flavor. Probably going to dump it, or even make another second runnings brew and blend it. Its interesting how much usable hops are thrown out if you are doing later boil/hop stand additions.

 

[daniel diggins]

I`m running an experiment with this idea in mind right now. I've brewed 8 lbs. of grain over 3.5 gallons of water. Let the grain hang over the mash bucket until all of the original wort dripped off to make sure the grain was in a state of "field capacity saturation" then sparged with an additional gallon of water and repeated the process of hanging until "field capacity saturation" to strip the grain completely of available sugars. I have then repeated the brewing process with the spent grain with an additional 3.5 gallons into a second batch, This time adding amylase enzymes and holding the grains at amylase enzyme reaction temps over several hours. I do not have a gravity meter so my process is strictly by taste of the mash to detect sugars. Tasting of the 2nd batch wort before the enzyme reaction process detected 0% sugars and a sour taste. After enzyme reaction detected about the same with very little distinguishable difference. Once brewed, the grain was again allowed to hang and drain until reaching the state of "field capacity saturation" without a second sparging and the second mash was condensed by evaporation over a low simmer in hopes of keeping a temp lower than the points of caramelization of sugars, just enough heat to create a steam, over the course of approx. 16 hours. Once the 3.5 gallons of small beer mash condensed to approx. 1 gallon the taste test yielded a wort with a higher sugar content than the original mash.

According to this crude experiment I think this yields more than 20% of the grains otherwise wasted sugar potential. Suggesting an ineffiecency of greater than 20% in my brewing process. This is probably a good place to mention the original 4 lbs. of grain was 100% malted barley.

At this point in the process the grain was considered spent and discarded. The plan now is to continue to condense the 2nd wort off into just above the dilution point of a malt syrup extract and add this wash to the 1st mash that is now working off in the fermentation chamber to increase its abv potential mid fermentation. I think this should just simulate a more efficient brewing process, based on my theory, but the data seems non existent on a similar tech. The only data set I've come across is fears of poor quality beer due to over extraction and burning of various grain congeners but I feel this should be a non issue considering the tech. of a successful malt extract industry being similar enough. However my grain bill does contain heavy peated malt, which might overextract the qualities of this specialty grain and create a "peat bomb" and overly smokey flavor. This might be a concern with specialty grains such as heavy peated or black patent malts or specialty grains along the same vane.

As far as necromancy of threads, from my search for info on this. This looks to belong here. Considering I'm referencing this thread for informational data years after it was created and not looking for a response, just reporting an experiment along this same vane. Excuse me if I`m wrong here on opinion of the etiquette of thread necromancy.

 

[daniel diggins]

Update: The 2nd mash was reduced down to 5.5 cups. 5 cups where collected. Half a cup was added back to reduce to a viscosity to something similar to Liquid malt extract. The 1/2 cup proved to reduce down to approximately 1/4 cup similar enough to a Liquid malt extract to be considered a success in producing Liquid malt extract. The sweetness and viscosity on taste and examination where consistent with a liquid malt extract. With the fluid in the pot lowered down to a smaller level it became more difficult to control temperature to prevent fear of any scorching of sugars or congeners. Taste did not reveal any evidence of scorching. Flavor was highly sweet like malt extract with a bitter off flavor I attribute to a cereal like taste and a slight hint of smokiness, not over powering, relieving the fear of over extraction of the heavy peated malt congeners. Any over extraction is within the cereal note flavor category that could produce an off flavor in a final product. I had another person sample it and it was described as "honey". This person is unfamiliar with brewing and Malt extracts.

A little math I've worked out that is the most fascinating: Considering that a half reduction of 5.5 cups would yield 2.75 cups of Liquid malt extract as a final measurement of reclaimed sugars. I have no way of testing whether this amount can truly be considered a malt extract based on sugar content beyond taste and viscosity. This measurement is converted over to 22 fluid ounces. a pound of liquid malt extract is approximately 9.5-10.6oz determined here:
https://www.homebrewtalk.com/forum/threads/how-much-volume-is-1-pound-of-extract.375047/

This would equal around 2 pounds of liquid malt extract recovered from the spent grain. Financially, that's a savings of about $6.50 if the liquid malt extract where purchased from my home brewing supply. to get the equivalent pounds of grain, 2lbs was divided by .75 to give 2.66 pounds of grain at approximately $7.50 local prices. Here's where it gets interesting, 2.66 is 33.25% of 8 lbs of the original grain bill, giving an inefficiency of 33.25% in my brewing process. this math seems to add up to the taste test of greater than 20%. But 33.25% puts 66% of the grains potential in the 1st mash if I have reached 100% efficiency. 33% is half of 66% and thus half beer if not condensed. I find that amazing the crude science and math has added up to the second run yielding exactly half or half beer. Thus the term half beer.

Extrapolating this home brewers such as myself are missing out on 2 gallons for every 4 gallon run. That's about a buy 2 get 1 free proposition on grain bills for me with 4 gallon run capacities. By either reducing the second wort down from 4 gallons to 2 gallons and running an additional 2 gallon separate fermentation of whole beer, running 4 gallons of half beer, or reducing the second wort down to liquid malt extract and using it as an addition to the next brews 2nd wort to fortify the next batches half beer into a whole beer.

The final 5 cups of diluted liquid malt extract where chilled off to temp. then added to the 1st worts fermentation to fortify it's ABV. This has several issues. 1: I lack equipment such as gravity meters to test sugar gravity or final ABV of the finished beer or any way to test the brix of the product LME against a control LME. This is an experimental recipe I have done this with so I have no way to compare it to a control batch for off flavor beyond is it drinkable? But this preliminary poke in the dark seems promising based on the crude science and sketchy math for both beer brewing,commercial malt extraction and increased efficiency of grain distilleries since the math seems to scale with production levels. I`m not sure if this is not economically viable in large productions comparing to the time, cost and space of spent grain extractions vs. costs of large scale grain purchases.

I think that's all I've got besides a final taste test of drinkable undrinkable which provides very little value considering it's a random test recipe. But will probably continue to do this on my next two runs to save up enough 2nd wort LME to compare that to an unadulterated 1st wort whole beer control.