Gelatinization and conversion of Corn

[JonDistiller]

Hi All,

I'm not getting to the OG that I would expect from my Bourbon.   I've tried a few variants on technique, and soak time, but still haven't managed to quite get where I want to be.  

Currently I'm using the corn in a cracked level of grind... some flour with the remainder being approximately the size of a normal barley grind used for beer.  I chose that, planning on trading some efficiency for ease of working.   I'm steep cooking it, raising the water to 210 and then adding the corn which brings it to 200 while stirring to avoid clumping or dry spots.   I've been experimenting with various soak/cook times, including 1 hr, 90 minutes, 2 hrs, and even an overnight insulated cook of 9 hours I read about on another site that resulted in a stuck sparge and a very long day.      My first runs I was trying to use just the enzymes in the malt... the math said there should be enough diastatic power, but I ended up with a 1.02 which was frankly unacceptable so I purchased high temp alpha and beta, as well as regular temp alpha.  (suspecting the malting of the grain was happening a few degrees too high and denaturing some enzymes)  I'm fairly consistently getting 1.04 with the enzymes, but I'd be expecting to be more in the 1.05/1.06 area if everything was happening properly.   

My next avenue of improvement I can think of, is that I need to be grinding more finely.   That leads me to my first question.   How large a hole do you guys use in the filter on your mash tun use when working with the more fine grinds?   Did you have to make modifications to your equipment compared to mashing malt based whiskey?  My second question... is there anything obvious I'm missing?    I've been a brewer for my whole life, but not worked with corn till much more recently.  I know unmalted corn is more of a challenge, but I'm really hoping to dial in my efficiencies a bit.  

 

 

[Hudson bay distillers]

I'm  surely not an expert on corn but there is a  great video on you tube by a guy named pinto shine all about using enzymes . It's a small batch but the science is the same . Dunno it might help ya . 

[Hudson bay distillers]

I'm  surely not an expert on corn but there is a  great video on you tube by a guy named pinto shine all about using enzymes . It's a small batch but the science is the same . Dunno it might help ya .It's called mashing 100% corn with enzymes. 

[Silk City Distillers]

Moving from roller milled coarse crack corn to hammer milled “coarse flour” increased our product yield by 20%.  We expected a chance, but it was a shocking improvement.

No other change, our typical SOP is steam injection with a 90 minute hold above 200f.

Is your tun heated/jacketed?  Do you have the ability to cook?  If not, going finer may be your only option.  Keeping your barley husk intact will help lautering, but lautering corn is always a nightmare (so don’t bother trying).

Also consider fermenting on the grain if you are utilizing glucoamylase.  While you won’t see a change in your starting gravity, you will end up with a higher final product yield due to enzymatic starch breakdown.

[JonDistiller]

@Hudson bay distillers I appreciate that, I am aware of Pintoshines vids.   I've been reading the stuff on homedistiller.org for a while, both during my learning process and during the few years I've been in process of opening up. 

 

@slick city distillers, thanks much!  that would make a lot of sense.   No, my tun isn't heat jacketed.   I'm using converted stainless steel barrels, so I have direct heat, but the thinner walls of stainless barrels means I have to use a bit of insulation to keep temps within the gelatinization range, when I attempt the longer time frames compared to purpose built stainless in a nearby friendly location that has been willing to talk with me.   I have 2 tuns, 1 with a finer mesh and the 2nd with a wider mesh.   I do have the ability to cook, but only via 2 methods.... either I can keep a rapid spin going via a stainless stirrer powered by a 1/2 inch drill so that I can keep direct heat on, or else I can insert a copper coil filled with heated water into the mash tun.  Thus far in my experimentation I haven't yet tried the second... just built what is needed for it.    So far I haven't had trouble keeping temps... which is a point of discouragement on why I'm not getting the results I'd expect from the math.

[JonDistiller]

4 hours ago, Silk City Distillers said:

Moving from roller milled coarse crack corn to hammer milled “coarse flour” increased our product yield by 20%.  We expected a chance, but it was a shocking improvement.

No other change, our typical SOP is steam injection with a 90 minute hold above 200f.

Is your tun heated/jacketed?  Do you have the ability to cook?  If not, going finer may be your only option.  Keeping your barley husk intact will help lautering, but lautering corn is always a nightmare (so don’t bother trying).

Also consider fermenting on the grain if you are utilizing glucoamylase.  While you won’t see a change in your starting gravity, you will end up with a higher final product yield due to enzymatic starch breakdown.

It's interesting... I actually fermented on the grain during my learning period in classes and was happy with the results.  I haven't tried it since we opened officially because I'm not willing to distill on the grain due to taste impacts that I learned  I don't personally like, but I haven't found a way to manage drawing the material to be distilled out of the grains in an effective way.     Have you found an effective way to pull the fermented product off (and out of) the grain/yeast bed?  How about recycling yeast?  Cleaning the fermenter?

[Hudson bay distillers]

When you say taste differences between grain in distillation and Laudered distillation are you  talking about scorched taste.

[JonDistiller]

On 9/4/2019 at 9:09 AM, Hudson bay distillers said:

When you say taste differences between grain in distillation and Laudered distillation are you  talking about scorched taste.

I was referring to the flavor compounds that (in my own limited experience) seem to make it across when grain husks are included in the still.   I grant I don't fully understand (yet) everything that's happening there, or why there's a difference to my taste in distilling on grain, when obviously we also raise the temps during the gelatinization/mashing process.   Nevertheless, to my own subjective mind there's a difference in flavor... just a bit extra bitter/tannin in the flavor profile, and my preference has tended towards the bourbon where sweeter elements are stronger in the total profile.   

 

[Hammer Spring Distillers]

We're just starting with corn (2 years in with potatoes, and making great vodka from them!).  We buy flaked (pre gelatinized) corn, and mill it to a flour just a fair bit finer than corn meal, but not all the way to bread flour.  We have a jacketed mash tun, and use Alpha, Beta, and Bioglucanase enzymes (no malted grains).  We're getting pretty consistent Specific Gravity of 1.08 (10.4% potential alcohol).  We also have a jacketed still, and distill on the grain.  Take everyone's advice about not trying to lauter corn - you'll die trying, and it won't benefit you much (unless you have a $20k centrifuge separator).

[Roger]

Jon - how many gallon beer ?

[JonDistiller]

On 9/13/2019 at 7:19 AM, Roger said:

Jon - how many gallon beer ?

I'm pretty small.   Generally doing either 60 gallon or 120 gallon batches.  

 

[glisade]

37 minutes ago, JonDistiller said:

I'm pretty small.   Generally doing either 60 gallon or 120 gallon batches.  

 

Jon, a beer gallon is the amount of water you use per bushel of grain (corn). Roger's asking because this is the main factor in your starting gravity. In other words, how many gallons of water do you use per bushel (56lb) of corn when you mash. Example: A 28 beer gallon mash would be 2 pounds of corn per gallon of water....or 28 gallons of water per bushel of corn.

[JonDistiller]

On 9/16/2019 at 6:31 PM, glisade said:

Jon, a beer gallon is the amount of water you use per bushel of grain (corn). Roger's asking because this is the main factor in your starting gravity. In other words, how many gallons of water do you use per bushel (56lb) of corn when you mash. Example: A 28 beer gallon mash would be 2 pounds of corn per gallon of water....or 28 gallons of water per bushel of corn.

Gotcha, I misunderstood the question.   I'm using 1.8 lbs per gallon.

[JonDistiller]

On 9/3/2019 at 3:49 PM, Hudson bay distillers said:

I'm  surely not an expert on corn but there is a  great video on you tube by a guy named pinto shine all about using enzymes . It's a small batch but the science is the same . Dunno it might help ya . 

Actually... earlier I responded that I already knew about the vids... and it was true... he's the source that I purchased my enzymes from.   Nevertheless, I started thinking about IT and how sometimes "turn it off and turn it on", or "is it plugged in" is the answer.   I went back and re-watched his vids.  There were one or two bits that I've been handling differently.   The biggest seems to be that I've waited to add my enzymes till I reached 170..   I figured holding above that, and up to 190 was all good, but his protocol was a little different, and involved adding them right from the initial warm up.   

I gotta say, thanks for reminding me to go back to basics.   Making that "minor" change, made all the difference, and now I'm getting what the math says I should.   

[Hudson bay distillers]

 Your welcome Jon glad you got it working.

Tim