Mashing Corn

stillwagon

Has anyone used rice hulls to avoid a stuck mash? What do you use to buffer the pH in your corn mashes to avoid a crash in pH during fermentation? I am doing 250 - 500 gallon batches, corn, barley malt and rye malt. PH crashes during fermentation and it is almost a glue like consistency. So I am thinking about using rice hulls to loosen it up, and buffering with calcium chloride, calcium hydroxide, gypsum, or chalk to stop the pH crash. I am just looking for others experiences.

Duck0fDeath

Did you use beta glucanase? I have heard that this stops the "glue" from forming during mashing.

nvnovrts

+1 on DoD, You might want to look at enzymes. What is the water to grain ratio? Any decent brew supply shop will have pH stabilizer 5.2 or some such name. Add this in when you are doing your acid/ph adjustments pre pitching. Sounds like you might be facing issues with conversion. Rice Hulls are mostly used for pressing off some really slimy white grapes, it gives the juice a pathway to flow through. In a mash it seems you would just be adding more solids.

Law_Of_Ohms

try steam flaked oats, theres heaps of husks and helps me with sparging.

crozdog

@stillwagon, sounds like your mash regime needs reviewing. As others have said enzymes do help. Have a read of this thread on AD - especially Jaybirds process on page 2.....

Duck0fDeath

15lbs corn 4lbs rice hulls and 5lbs malted wheat for a 10 gallon batch... for a 500 gallon batch you need much more haha

stillwagon

We ran a 60/40/10 corn/barley/rye at a local micro-brewery that was willing to do the mashing and fermenting just to see if it was me or the mash. It gummed up all their equipment during the sparge. So that is why I am wondering about the rice hulls. That is the one thing I/we did not do, and everything I have read since then, suggests them to avoid a stuck sparge. This was a 300 gallon batch/300lbs of grain. We ended up with about 200 gallons of wash @ about 8% maybe a little less.

We had to add calcium chloride, chalk, and gypsum to balance out the water according to their calculator, which accounts for their water which is filtered and everything is stripped out. They said I would probably need to increase these buffers to ferment on the grain to offset the effect of the tannins and proteins would have being present during fermentation. They always sparge as they are beer makers, and have no experience using corn. They had never had such a gelatinous mash as that was with the corn.

This is why I wanted to throw it out to you guys, should any of you have had experience with corn mashes of any significant volume. I have had 5 gallon test batches work out fine. 300 - 500 gallon batches are a different animal.

crozdog

@stillwagon are you cooking it? can you provide detail on your mash process & the one used by the brewery?

I would recommend enzymes and trying to gradually scale up from a 5 gal smaller batches eg 50 then 100 etc .

try putting the numbers through a brewing program to check your efficiency.

stillwagon

In both cases we preheated the water to about 180 and then mixed in the corn, let it rest to soften up, then cooled it to about 160 to add the malt. That brought the temp down to about 145. We kept it there for a couple of hours for the starch conversion. Then at the brewery we tried to sparge. It was very difficult due to the glue like consistency. They had never experienced this with their barley mashes.

Once it was sparged and in the fermenter it was cooled to about 80 degrees and pitched the yeast.

All the water was adjusted for ph prior to mashing. We got a good conversion, just a poor yield because of the stuck mash. It fermented out in about 4 days.

When did my large batch I added no buffers the ph crashed and I got about a 1% yield. The fermentation stopped due to the low ph. I got a good conversion of starches in both batches.

grim

What kind of corn - precooked or cracked - if cracked, how fine are you re-grinding, if at all?

Lautering a corn mash is incredibly frustrating and depending on your overall percentage of corn, starts to become damn near impossible to do effectively. This is the reason you see so many bourbons fermented and distilled on-grain.

How long were you resting at ~180? If you are using cracked/ground, I'd be surprised if your efficiency wasn't very low (this makes me think you are using pre-gelatinized corn).

What is your starting water pH, what is your pH immediately prior to pitching yeast, and what pH level are you considering a crash? What you are describing is atypical, and if you are having such a big problem with water chemistry, those guys can't possibly be making decent beer. If they can make beer, the water is fine to mash, the water chemistry requirements are essentially identical, don't add any amendments or make any adjustments that they don't.

stillwagon

The only problem we had at the brewery was with the sparge. PH was adjusted for prior to mashing and went like clockwork through fermentation.

I was the one experiencing the pH issues but that was because I wasn't conditioning the water as they had with calcium chloride, chalk and gypsum. Starting pH for me was 6.8. I considered it a crash when it registered below a pH of 3.

The corn is a flaked maize sold by Briess. We didn't grind it at all. It became gelatinous in their mash tun and mine. That is why I am going to try the rice hulls. This was also recommended to me by another brewmaster. So I am hoping that deals with the stuck mashes.

I am considering building a jacketed boiler for my still, at least for the grain washes. I have no problem running the rum with the internal elements.

grim

I still don't think it is the water, not that low. Assuming their pH meters were calibrated - pH of 3.0 is very low - I don't believe yeast alone could possibly push down to a 3.0, sounds like you might have had some friends along for the ride (probably lacto). A pH of 3 would have been noticeably sour, did you happen to smell or taste the ferment? What did you guys do to unstick the mash in this big batch? Did unsterilized mash paddles go back in? Hands? Fingers? For just a taste? :)

What was your yeast pitch? A 200g/7bbl yeast pitch is pretty darn big, did they repitch from a previous fermentation? Or leave the cake in the fermenter and pitch on it? If you under-pitched, yeast might have been outcompeted early on. Surprised you decided to scale this big on a test run, heck, you are talking about what, like $200-250 in yeast alone here! I feel for you since this was a very expensive test when you factor in the grains.

The Briess flakes are pre-gelatinized, so no cereal cook needed, so your temps and yields are probably fine.

If you want to continue down the lauter path using the existing equipment, you'll probably need to change your recipe. If you want to experiment with a recipe that may work, push the flaked corn to the minimum, 51%, and increase the barley to compensate (not the rye, you'll create a whole other problem), as well as adding in the rice hulls. Guessing Briess wouldn't probably recommend any more than 20-30% as total mash volume in a brewing situation. Even with these changes, corn mashes will never lauter like straight malt mashes.

You had plenty of diastatic potential with your grain bill, so I don't expect that the run-of-the-mill enzymes would have any impact here. Alpha/Beta amylase - don't bother. Besides, reducing your malt percentage is just going to make more of a mess.

Batch sizing is important. Just because you can squish out 5 gallons using a paint strainer bag doesn't mean that you can lauter it (unless you want to spend your day squishing - I'd keel over dead halfway though, I'm sure). You can mix a 10g mash with a wooden paddle, in a 100g mash, you break the paddle!

grim

FYI - Corn has little in the way of beta-glucans compared to rye and wheat. If you decide to push the rye percentage upwards, adding beta-gluconase enzymes may help a bit, but I still wouldn't expect miracles.

Realize though, that your recipe, if fermented on grain, should be working just fine without much additional tinkering.

stillwagon

I would prefer to ferment on the grain. I would also prefer to just dump the whole mess into the still but that will require a steam jacketed still and an agitator, so this will be down the road a bit financially.

I have a brewmaster that is going to come in and work out a process with me on my equipment. He feels confident that it can be done. So I am going to leave it in his hands for now and continue producing rum. That I have down and consistent.

Thank you for your thoughts and suggestions. I will keep them in my notes as we move forward.

Duck0fDeath

The term Glue comes from Glucanase :)

Lloyd

Wrong! It comes from trying to ferment cooked rice =))

Law_Of_Ohms

How about fermenting on the grain and using a wine press for the bits left over?

crozdog

@stillwagon - keep us in the loop on progress please. I reckon you do need rice hulls & lots of em. I had a similar experience 2 weekends ago with 10kg briess flaked maize, 4 kg malted barley & 2 kg malted rye. Even though I cooked it & used enzymes (got good efficiency) but it didn't want to lauter - grrrr.

I have read that using 1/4 of your grain weight in rich hulls works. Give that a try

nvnovrts

@Law_Of_Ohms said: How about fermenting on the grain and using a wine press for the bits left over?

that is a good idea.

punkin

Except people who have tried it say it doesn't work:

@zymurgybob said: I've used the wine press with a muslin liner, and it was a dismal failure. After the first small bit of liquid, the corn plugs all the holes in the fabric, and attempting to fix that by winding on more pressure just resulted in almost microscopic high-velocity jets that fired the juice out from between the press basket slats, way over the collection tray, and way out into my driveway. But yeah, I've also heard that it works, but not on my planet.

nvnovrts

Try one of the fruit presses. with the metal mesh baskets. I'm guessing they are 3-5mm holes. No need to line it with extra cloth. You still get the occasional "high pressure jets" make a rough alum foil wrap for it and problem solved. You get minimal amounts squeezed through the holes. run the press juice through a strainer. You need to let it settle after the pressing as its pretty cloudy/yeasty. I tried the brew bags and that works but its a PITA and makes a nice mess.

The press works for me.

Law_Of_Ohms

i have 500L do to......

Lloyd

Maybe something like the DIY honey extractor ?

grim

@Law_Of_Ohms said: i have 500L do to……

Look on the bright side, you'll have arms like Schwarzenegger after a few batches.

Lloyd

Trying to visualize Law of Schwarzenegger and it ain't pretty.

CothermanDistilling

yet another market for @Lloyd to get into so we don't have to pay $30k...

Separating Corn Mash - The Liquid Solid Separator allows reprocessing of ethanol stillage

grim

Cheap hydraulic press and a spare stainless drum. If you are handy with a welder you can rig something up.

nvnovrts

40L AG mash is two passes in the press. I think its a 8-L basket. If you get a 40L model with a motor.? This is something I'm thinking about as well, as there is a 400L still on the horizon. Multiple pressings would suck. We use a Bucher basket press at work, but that baby runs about $250K.

Wine Presses @ Summit Wine Solutions

crozdog

butchcoolidge tried a washing machine over on AD a while back with messy results.

Here is a similar idea used to grind and separate apple juice for cider http://vimeo.com/29752225

The idea came from this article: Converting a Washing Machine Into a Homemade Cider Press