Recording what happens in an all corn plus SEB enzyme mash

[Fills Jars Slowly]

I just mashed the second go 'round of a Booner's batch. I am interested to see how the mash process separates starches from the grain and turns it to sugar. My first Booner's mash yielded an initial gravity of 1.06 and finished at .996 for a 8.4% abv wash. This time, I did some experiments with time and temperature with the operating theory being that SG is mostly determined by the efficiency with which starches are separated from the grain, and that there is some optimal time, pH, and temperature to separate those starches. I wanted to reach the optimal time and temperature to separate the maximum amount of starches.

My plan was to:

1. Mash in 25 lbs of cornmeal into 14 gallons total volume of liquid at pH 5.9. The liquid is 13+ gallons of water with backset added to adjust pH and 6g calcium chloride + 3g gypsym + 3 tbs DAP for the yeast.
2. Adjust temperature and time to maximize extraction, using a mix/stir apparatus to use a drill to agitate the batch while heat was added or to cool it. For fast cooling a sanitized copper coil wort chiller was added.

It has already been proven that starting gravity is a product of how much starch is separated from the grain. Finishing gravity is a product of starting gravity and how much of the SG is fermentable. You can have a high SG but lots of non-fermentables result in a high finishing gravity. If everything works right, you get the maximum starting gravity and it is maximally fermentable, resulting in a low finishing gravity. That is, lots of the sugars in the mash are converted to alcohol.

The process:

For the first part of the mash I took intermitent readings of gravity with my refractometer from the homogenized (stirred up) mash. Some bit into the experiment, when the mash got to that brains/cloud consistency after resting, I started measuring both the gravity of the clear liquid part and the gravity of the homoginized mash each time I stirred it.

pH hit 5.9 for the strike water. Mixed in the SEBStar at 195 and then immediately mixed in the cornmeal. It liquified almost instantly as I fed in the corn in a continuous medium sized stream. pH of mash after 1 hour is 5.8.

Mash Notes:

Minutes Temp SG Starch Test Negative
2 180 1.042 No
10 177 1.047 Yes
20 175 1.051 Yes
30 173 1.052 Yes
60 166 1.055 Yes
90 160 1.056 Yes

At this point I note that SG is starting to level off needing longer and longer rests for smaller and smaller gains. It appears that some of the harder to extract starch was left behind by not keeping it at a high enough temperature for long enough. So, I turned on the mixer and turned on the burner. Temp rose steadily at a bit more than 1 degree per minute before I turned off the burner and stirrer after 20 minutes when the temp reached 185. A gravity reading after this temp rise gives 1.058. So:

Minutes Temp SG
110 185 1.058
140 180 1.059

Still not much movement except for what was achieved during heating. So, I heated another 15 minutes, stirring, to 190:

Minutes Temp SG
175 187 1.061 (measured clear liquid once mash settled into the "brains/floating cloud" looking state.)
200 186 1.064 (same method as above, filled dropper from two clear spots in different parts of pot)
225 185 1.065 (same method. Filled dropper from multiple clear spots in different parts of pot)

Mixed to homoginize and took readings again:

Minutes Temp SG
235 167 1.062 (homogenized mash)

Put the spurs to it and extract every bit of starch we possibly can. Be greedy. Turn on the mix and heat and take it to 194 over 20 minutes.

Minutes Temp SG
255 194 1.062 (homogenized mash)
285 185 1.066 (cleared liquid)
287 180 1.064 (homogenized mash)
315 178 1.067 (cleared liquid)
317 170 1.064 (homogenized mash)

OK, this is as far as I am willing to go. I have gelatinized for 5 hours plus and heated the mash from the 160s to the high 180s low 190s three times. Let's say the SG is in between the final cleared and homogenized readings at 1.0655.

Here is what is happening - when I initially dumped the corn in the water, quite a bit of the more easily soluable starch was dissolved, but not yet converted to complex or simple sugars. It took some small period of time (3-9 minutes?) for the alpha amylase to convert this initial starch load to dextrins and simpler sugars. During this time, the iodine test shows positive for starch while gravity is about 1.042. After 10 minutes though, gravity continues to rise to 1.047, 1.055, and finally 1.065+ over time without ever having an iodine test positive for starch. This is because throughout this process more gelatinization is happening (especially after reheating the mash) releasing more starch into solution, but the enzymes are almost immediately converting it to sugar. So, the bottleneck in getting to the maximum extract is mainly the speed of gelatinization. If we could gelatinize everything in say, 1 hour, that is all the time that would be needed before cooling to below 150 for the next step. Heat is the key. The SEBStar liquifies the mash, but it still must be held at temps of 185+ for a period to release the most stubborn starches.

The regime for fastest gelatinization might be:
1. Use 1.5 times the standard enzyme dose, or 15 grams to allow for denaturization loss.
2. Heat the strike water to 193, turn on the mixer and add SEBStar and corn. This will bring the mash to about 180.
3. Continue to heat and mix the mash to achieve 193 overall (about 15 minutes).
4. Turn off the heat and mixer and rest until gravity stops increasing (60-90 minutes).

Once gravity is maximized, in this case at 1.0655, correct pH. I added backset to bring the mash to 5.3. Then I put in the sanitized wort chiller and dropped the mash temp to 150 and add SEBAmyl.

Rest 2 hours then cool to pitching temps. Pitched yeast at 97F. Blowoffs bubbling within 30 minutes.

About 1 quart of backset was used to bring the mash pH down before the addition of SEBAmyl. Added to the initial infusion volume, this means we now have 14.25 gallons of liquid and the gravity is 1.0655. This is 933.375 total points, divided by 25 pounds of grain is 37.335ppg, or 96% efficiency, if you figure corn to have a potential of 39 ppg at 100% efficiency.

[woodshed]

Very nice work. Thanks for posting that.

[Fills Jars Slowly]

Sure thing, Woodshed. This intrigues the hell out of me. I just want to see how the final product tastes. By all accounts, I will not be disappointed.

[MitchyBourbon]

Very nice write up Fills Jars Slowly. 5 hour mash, that's a marathon. Very interesting findings, mash time is driven by how fast you can gelatinize the starches.

[FullySilenced]

Has a little time on your hands did ya

Not bad for a Texan... LOL

Happy Stillin

FS

[Fills Jars Slowly]

Yeah, I had the day off and wanted a baseline to judge performance of my Booner's mashes. Figured I would wring every point out of this one to see what is possible. I will probably be lazier than that on an average day.

Hey, does anybody know which gravity reading is more indicative? The one where the entire mash is mixed up and there are bits of corn in my sample or the one where I let it settle and just take the clear liquid? The clear sample was always several points higher, but even with the crud in it I got a nice sharp reading from my refractometer.

[CRACKERCREEK]

I would err on the side of the homogenized # or let the entire wort cool and settle ( but this could take days) the reason your different readings ,as I have found when using both a refractometer and hydrometer is From the suspended proteins. This was always a real issue for us when doing Wit beers.

[kurgan]

Yeah, I had the day off and wanted a baseline to judge performance of my Booner's mashes. Figured I would wring every point out of this one to see what is possible. I will probably be lazier than that on an average day.

Hey, does anybody know which gravity reading is more indicative? The one where the entire mash is mixed up and there are bits of corn in my sample or the one where I let it settle and just take the clear liquid? The clear sample was always several points higher, but even with the crud in it I got a nice sharp reading from my refractometer.

If I recall Smiley's book says the clear settled liquid is what you want, i'd have to dig the book out and let you know for sure.

[Fills Jars Slowly]

Thanks for the input CRACKERCREEK and Kurgan. It seems a clear cut answer on the question of getting the most useful gravity reading in situations like this is a bit up in the air. The mash/wort experiences varying states of turbidity at different points, and a particular mode of measuring gravity may react to a given condition differently from another.

My somewhat informed experience as an all grain beer brewer gives me the intuition that concerning refractometer measurements, large particles don't impact the readings by a significant amount. The liquid layer through which light is refracted is, in that case, analogous to a lake of clear liquid with some pebbles floating in it. The reading we get is indicative of the liquid, not the particulate matter. However, if the stuff floating in the liquid is too fine and makes up a large enough portion of the "lake", then we get a fuzzy refractometer reading that does not give a sharp line on the gravity scale.

The fact that my refractometer readings were never fuzzy (which I have seen in some cases) might mean that my homogenized readings were most accurate. The readings I took of clear liquid were, by their nature, taken from a more stratified sample. If the sugar tends to concentrate in the clear liquid, then those readings might be falsely high compared to the average gravity throughout the sample. It certainly is enticing to have a completely clear sample that indicates a really pleasing (higher) gravity reading. Still debating with myself which is best, but leaning toward homogenized as long as it gives a legit refrac reading and is not fuzzy.

On a completely different note, I want to wish Woodshed the best and fastest recovery possible from his recent health issues. Search the forum and read the "Woodshed" thread for details, but God speed and good luck in overcoming those scary curveballs that life throws at us all, seemingly at random. Woodshed has been an inspiration and a leader for this forum, and we could all do with a lot more of his valuable and straightforward outlook. He and his family deserve nothing but the best, and I wish them that.

[kurgan]

Here we go. Taken from my copy of Ian Smiley's book "Making Pure Corn Whiskey"
(second edition) Chapter 7 Fermentation page 79.

"To measure the Originating Gravity (OG) of a grain mash, it's important to
collect a sample of the mash that's almost devoid of mash solids. When a mash
has completed its conversion rest and has settled for a while, there's a clear
light yellow liquid on top of the mash. A sample of this clear liquid can be
carefully collected in a hydrometer cylinder and measured with a standard
winemaking hydrometer."

Now i'm not saying Smiley's book is the end all to be all resource, but this
does back up what I was taught by my Grandaddy "all your alcohol will be up top
in your mash".

[CRACKERCREEK]

10-4 or +1 on that

[Fills Jars Slowly]

I was taught by my Grandaddy "all your alcohol will be up top
in your mash".

Seems about right to me. I think your Grandaddy was referring to a fermenting or finished mash/wash, where the less dense ethanol will tend to float on top of the more dense liquids and solids. That would mean that gravity samples taken from the top would indicate higher ABV than was really present in the entire fermentor.

A sample of this clear liquid can be
carefully collected in a hydrometer cylinder and measured with a standard
winemaking hydrometer."

I agree with Smiley 100%, but he is speaking of reading gravity with a hydrometer. Using a hydrometer, large amounts of suspended solids prevent a proper measurement. Thus, the only thing left to do is take a clear sample and live with the fact that the gravity of that sample could vary from the gravity of the mash on average. My gravity measurements were taken with a refractometer, which measures gravity a different way and might be more tolerant of suspended solids. Sometimes, even with the refractometer, the substance I am measuring is too cloudy and the instrument shows a blurry line that doesn't give a clear reading.

In this instance, even after homogenizing the mash the refractometer showed a clear reading on the Brix scale. Since my refractometer plate only had a goodly number of specs of cornmeal floating in a mostly clear pool of liquid, I doubt that the refractive index of the liquid was affected much by the flecks of cornmeal. So, it could be that I got a good reading of the average mash gravity using this method.

In a cleared sample taken after letting the mash settle, there is a chance that whatever part you are sampling is not representative of the average. In my experiment the cleared samples were always higher gravity than the homogenized sample. This could mean that the homogenized samples were artificially low (due to suspended solids messing up the gravity reading), or it could mean that the cleared samples were artificially high (due to sugars concentrating in the cleared portion).

My hunch (only a hunch) based on my experience reading refractometers is that the sharp reading I got from the homogenized mash is an indication that the reading was accurate, and consequently that the cleared readings were skewed high. It is likely all horseshoes and hand-grenades anyway, since in this kind of mash (on the grain, no boil, enzymes added) more starches will be released by the grain, converted to sugar by the enzymes, and consumed by the yeast during fermentation. I could keep careful track of the still output to try to nail down the actual numbers.

[kurgan]

True, he was talking about finished mash. I see your point about the homogenized samples, and agree that it's probably like you said "horseshoes and hand-grenades". I like the refractometer for an all grain and fruit mash, I trust it more for these. I usually leave the hydrometer for beer wort and sugar mashes. Keep us posted.

[Fills Jars Slowly]

I stripped 10.5 gallons of this wash in my pot still. The final gravity came in at .996. 230 ml of fores were discarded, then collected 2.2 gallons of low wines at 37.5% abv overall. The first distillate came off the still at 60% abv, declining to about 13% by the time I stopped the run. I have not tried to reverse engineer the abv of the mash from these numbers, but it seems like it did fine.

[Fills Jars Slowly]

I am doing more of these mashes and seeing a pattern in results. The higher the gelatinization cook temperatures and the longer the time, the more starch comes free of the grain. In my runs finishing gravity is always about .996, so far. Starting gravity is a function of how hard and long I cook the corn and how much starch I separate from the grain. Right now, tonight, I am trying something similar to Jimbo's no boil method and insulating a mash heated to 193 in blankets for an overnight rest. My hope is to maximize OG and minimize time spent laboring over a hot pot.

There is definitely something to the old-timers methods of boiling the snot out of a cereal mash while stirring like crazy to keep it from scorching. It ensures that starches are freed from the grains. My experiments right now are aimed at finding the "most gain least pain" set of processes for my setup. Since my drill driven mixer operates hands free, the next step would be to try to emulate the old timers by heating to boiling while stirring, enzyme denaturing, be damned. Once liquified, I imagine the mash would stay that way when heated to boiling.

[scuba stiller]

Looking forward to your continued analysis Fills Jars Slowly.

[Fills Jars Slowly]

The result of the mash started last night was a fermentation with an original gravity of 1.06. I know from previous experience (documented at the top of this topic) that when I pull out all the stops I can get 1.064 - 1.065 from this recipe. Given the work involved in doing that and the ease of the heat-and-rest method I won't be chasing those extra 4 or 5 gravity points on every mash. Too much work for too little return. Plus, 1.06 OG gives me a finished mash that is between 8% and 8.5% abv, which suits me fine. No reason to jump through hoops to get the extra half percent or so of alcohol.

The only thing I have found through my experiments that is at all different from Woodshed's method as originally posted is putting emphasis on time spent in the gelatinization stage, as opposed to the saccharification stage is what seems to make the difference to efficiency. Pretty much, if you can get the starch out of the grain, the conversion will happen (following proper protocols, pH, etc.). The bottleneck is in getting the starch out, and even with enzymes, heat and time seem to be the way to accomplish that. So, my current best practice for the cereal mash stage is to go as long as possible with as much heat as possible. For saccharification, a couple or three hours in the 140s seems to do the trick. In all my experiments starting gravity, as measured by refractometer, never seems to change after the gelatinization stage.

For folks like me that enjoy a no-boil type method, doing an overnight cereal mash followed by a shorter conversion rest the next morning might be satisfactory.