Starch conversion testing process

[Mr_Beer]

I decided to do an actual 100% Corn whiskey recipe.
And it got turned into a comparison experiment – traditional US-05 yeast versus Angel yeast.
And then it turned into another puzzle of what I might have done incorrectly with the traditional mash approach.

Any help or speculation would be appreciated.

My questions all have to do with the ‘Traditional Mash’ process – recipe #2 below

Is an iodine starch test a valid indicator or am I relying on something that needs to be corrected?
Is the iodine starch test compromised by higher temp sample?
Should I have waited more time to allow conversion – 26 hours would seem to be adequate especially with the addition of enzymes.
Why was the OG so much lower than the projected – 1.040 versus 1.060?


Angel Yeast Experiment – recipe #1
15 gallon of 97℉ water from tap
Stirred in 40 pound corn – crushed to almost corn meal consistency
Hydrated Angel yeast
Pitched and waited.
Done in about six days with a FG of .998


Traditional Mash with US-05 Yeast – recipe #2
15 gallon of water heated to 195℉
Stirred in 40 pound corn – crushed to almost corn meal consistency
Added 2 tbls SebStar HTL (High Temp) enzyme
Let temp drop gradually – 6.5 hours to 133℉
Added 3.5 tbls SEBAml GL (Low Temp)
Waited 4 hours and iodine starch test showed converted but when the mixture was again stirred it indicated not converted. Very puzzling??
Left overnight in covered mash pot.
Mixture had foamy top – almost like it had started to ferment.
Temp was 118℉ even though it had set overnight.
After stirring an iodine starch test mixture indicated it was not converted
Inserted cooler and lowered temp to 82℉.
Hydrated US-05 yeast and pitched because of fear it was starting to ferment with wild yeast.
OG measured at 1.040 versus a projected (calculated) goal of 1.060

[howie]

i think your iodine question was answered in a "wheat & og" thread you started about a month ago?
did you test the temp of the mash after you dunked 40lb of corn into 195°F water?
using a strike water calculator backwards, the water would have dropped to about 170°F straight away.

[Mr_Beer]

Thanks for your reply.

You are correct, about a month ago I had a problem with wheat. My conclusion was that my temps were too low since I set them at the gelatinization level. I did not understand that a higher temperature would be tolerated. I did a second identical 'batch' with YAY without difficulty.

This is essentially a continuation of my experiments-- trying to understand the behavior for traditional mashing process.
Because the grain was corn I raised the temp to 195°F and added the grain. I did not consider the temp loss due to grain addition. Thank you for pointing that out.
My notions were that at a temperature above 190 the SebStar HTL (High Temp) enzyme would denature so that was the upper limit of my temp.
Additionally it is obvious that my W/G ratio was fairly high at 2.7 but I do not know if that was a contributing factor.

I added the enzyme at essentially the same time as the grain in an attempt to keep the mixture viscous enough to be stirred and the result would be not too thick and ensure that the enzyme would not denature. That part worked -- the mixture was fairly thin throughout the 26 hour process.

If I had raised the temp to 210°F or so and then added the corn and waited 10 minutes or so would the mixture have gotten so thick it could not be effectively stirred? I have this fear of a thick 'glop' in the mash pot that could not be thinned out with the enzymes.

All that said, even at 170°F starting it should have converted over the 26 hour period -- at least that was my notion.

My understanding of the dynamics may be incorrect -- if so I would appreciate any suggestions/education.

[howie]

i don't have heaps of experience with corn
you don't have to fear the glop with enzymes, they work pretty fast anyway, almost instantaneously.
i add the corn + enzymes as the mash is heating up to 87C
my high temp alpha works at 100% activity at 87°C (188°F), but only 20% at 70°C (170°F), PH is important too.
with enzymes i only cook the corn at a constant 87°C for maybe 1.5 hrs before cooling it with a cooling coil to 65°C for malted grain/gluco addition.
also, it's not a bad idea to use strike water calculators to get your water to correct temps.

so i reckon temp was your main original problem, maybe the changing iodine tests are indicating that starch is still being slowly released from the corn at the lower temps, where the aim is to extract all of the starch at the higher temps?

[The Booze Pipe]

Check out the mashing procedure viewtopic.php?t=65703 it might help answer some questions. I used it, ended up gelling the corn at a low temp as well, I think around 160f but I still got a good conversion, OG of 1.060.... no iodine tests done...wish I could help more.

[Dancing4dan]

Mr_Beer "Added 2 tbls SebStar HTL (High Temp) enzyme"

At what temperature was this added?

How long did you cook the corn before adding " tbls SebStar HTL (High Temp) enzyme"

The link Boozepipe provided likely contains your answers.

Dried corn is very hard and takes time to hydrate. follow the link and you will get the idea.

[Bradster68]

I always use some HT enzymes as sacrificial, this thins things so you can cook easily. After your cook time is done and it's cooled back below your enzyme temp. Then I add a little more so as to not denature it.
My corn efficiency is bang on every time with this process.

[The Booze Pipe]

I always use some HT enzymes as sacrificial, this thins things so you can cook easily. After your cook time is done and it's cooled back below your enzyme temp. Then I add a little more so as to not denature it.
My corn efficiency is bang on every time with this process.

I like this idea. What method are you using to cook/mash corn? And what size batches are you doing?

[Bradster68]

I always use some HT enzymes as sacrificial, this thins things so you can cook easily. After your cook time is done and it's cooled back below your enzyme temp. Then I add a little more so as to not denature it.
My corn efficiency is bang on every time with this process.

I like this idea. What method are you using to cook/mash corn? And what size batches are you doing?

I have a 20 gallon pot I fill with hot water,add my feedmill cracked corn,which I grind in my modified rollermill. It holds 50lbs of corn. After it boils,I simmer for 2 hours, stirring occasionally. I time this so it sits overnight, I cool to pitching temp in morning. All my malted cereal grains are done in a separate pot,also resting overnight. I do 40 gallon batches,and do mostly bourbons.
And of course Bills rum from time to time.

[bilgriss]

I believe that your temperature drop would be too much in the initial gelatinization phase. With a ratio of 15 gallons to 40 pounds, it's going to be quite pronounced. If you use 20 gallons of water, it will have much more mass relative to the corn, and also start as close to boiling as you can. Keep the mash insulated and give it time. During the ferment, if there are sufficient enzymes still present, you should continue to have some measure of conversion as well. The best measure of what you get from the comparison will be the final yield between the two.

If you want to get even better conversion, cook the corn. Apply enough heat to keep it in the 190 range for a while. Enzymes help.

[Mr_Beer]

Thanks for everyone who has taken the time to respond.

It is clear that there are no precise or easy answers. If there were, then there would not be so many threads on this forum regarding this topic. It is further clear that my prior experience with beer and associated all-grain mashing does not directly translate to mashes for distilling with a high percentage of adjunct grains.

That is probably my biggest mistake – thinking I understood the process.

My tentative conclusions are…

Any process must account for the existing equipment and available containers and space. Hence the variability of the process by different members.

Yellow Angel Yeast is much easier to use for adjunct grains and seems to be very effective. It is the winner on a process simplicity basis. Since there is no OG value associated with this method, it is hard to determine the efficiency of the process. Time will tell regarding associated taste characteristics

For the traditional mashing process …
• Grind my grain finer – my current process is not as fine as some suggest and has larger chunks much liked cracked corn.
• Reduce the grain/water ratio to about 2:1 – allows for a thinner mash. For my 20 gallon pot the grain would be 30 pounds of corn with 15 gallons water. That will bring it to within about 2” of pot overflow.
• Heat water to boiling (212℉) and insert grain while stirring constantly. Recognize that temp will drop as grain is added.
• Let it ‘cook’ for at least three hours at this high temp. Stir every 15 minutes or so to promote the gelatinization process. Possibly apply additional heat to maintain the high temp but scorching is a possibility if it gets too thick. Since I use a 20 gallon pot with propane heat instead of electric elements, scorching may not be an issue.
• Add SebStar HTL enzyme and stir.
• After mixture thins out add other crushed grains – wheat, barley, etc.
• Add some additional SebStar HTL enzyme
• Let cool to 140℉
• Add SEBAml GL (Low Temp) enzyme.
• Let stand for another couple of hours
• Insert cooling coil and cool prior to pitching.


Special thanks to Howie, Bradster68 and blgriss for describing their process. Much appreciated.

[The Booze Pipe]

It is further clear that my prior experience with beer and associated all-grain mashing does not directly translate to mashes for distilling with a high percentage of adjunct grains.

That is probably my biggest mistake – thinking I understood the process.

And so it goes

[Mr_Beer]

As mentioned early in this thread, I decided to do identical batches with Angel Yeast and US-05.

The Angle Yeast batch process was falling down easy to use and was done in six days. Result was darker yellow than the US-05 and had 20% more volume.

The traditional mash method with US-05 was very pale and 20% less volume than the Angel Yeast batch and took 12 days. Depending on your viewpoint, the process has substantially more steps and possible issues during the process.

Distilling comes next follow by some form of taste testing.

I will update in several months.

[MooseMan]

I look forward to the update with your impression on what it produced.

[howie]

As mentioned early in this thread, I decided to do identical batches with Angel Yeast and US-05.

The Angle Yeast batch process was falling down easy to use and was done in six days. Result was darker yellow than the US-05 and had 20% more volume.

The traditional mash method with US-05 was very pale and 20% less volume than the Angel Yeast batch and took 12 days. Depending on your viewpoint, the process has substantially more steps and possible issues during the process.

Distilling comes next follow by some form of taste testing.

I will update in several months.

that's seems quick for AY, how did you know it was done?

[Twisted Brick]

that's seems quick for AY, how did you know it was done?

Were you able to take a FG reading? What might you attribute the difference in 'volume' of the two test samples? Since enzymes/yeast don't normally 'create' volume, would it be safe to conclude that the YLAY did not gelatinize and break down the overall grain structure that the separate enzymes/yeast sample did?

[Mr_Beer]

Fermentation was in a 20 gallon HDPE barrel with heat belt(s) to make sure temp stayed at 89F. Many threads indicate that lower temps restrain the fermentation and significantly lengthen the fermentation time.

In response to the "howie" question, the FG was .999 or possibly .998. Did not move for the final day.
The US-05 batch remained at 1.012 for two days so I stopped it.

In response to the question regarding volume, I can only speculate. Other threads, here and on other venues, suggest that the YLAY added to the initial liquid due to the alcohol produced during fermentation. The YLAY folks are fairly secretive about their process and methods -- an obvious position to protect their intellectual property rights. For all I know they may have a way to avoid the typical gelatinization process in favor of some other chemical bond 'fiddling' activity. The difference in color and volume was very significant so there must be some other factors involved here.

They have a substantial market share in the EU and Asia regions. I could not find good market data but it is clear that the YLAY product is on the ascendancy for commercial production.

Unfortunately, I can only report the result.

Other forum threads suggest that YLAY yeast results in more 'grainy' flavor in the final product. That will be the final measure -- what it tastes like.

[NormandieStill]

In response to the question regarding volume, I can only speculate. Other threads, here and on other venues, suggest that the YLAY added to the initial liquid due to the alcohol produced during fermentation.

When you talk about different volume what are you referring to? Total volume in the fermenter? Volume of clear beer in the still? Volume of low wines at a certain and? I don't see how, if you started with the same volume of ingredients, you could have a radically different volume at the the end of the ferment. I'm fairly certain that physics would have something to say about that.

[Twisted Brick]

In response to the "howie" question, the FG was .999 or possibly .998. Did not move for the final day.
The US-05 batch remained at 1.012 for two days so I stopped it.

My experience with US-05 has been consistent, FG dropping to .994 - .998 (rarely over 1.00) using either restaurant-grade medium cornmeal or finely milled whole corn. I'm curious how much the starch content in your feed corn may be contributing to your higher final gravity. Supposing a starting gravity of 1.060, the difference of ethanol produced between 1.012 and .998 FG is considerable.

[Mr_Beer]

To answer NormandieStill: The difference in volume was the measured low wines after fermentation was complete in a 20 galon HDPE container. Same recipe -- 15 gal water and 40 pound of corn. Ferment on grain. Volume of the batch was measured at 19 gallons starting.

Drain and squeeze. Transfer the liquid from the container to settling carboys using aquarium pump -- very easy to get accurate measurements. Obviously the trub was left in the fermentation containers and discarded.

YLAY batch resulted in 13.95 gallon after transfer
US-05 batch resulted in 11.1 gallon after transfer

Neither batch has much noticeable settling trub.

To answer TwistedBrick: You may want to review the initial thread -- I was complaining about getting an OG of 1.040 instead of about 1.060 that I expected. Lots of discussion and help by members. You can review my summary -- it is clear that my traditional mash approach needs some changes to reach an acceptable OG. That said, regardless of the starting process of 1.040 I was surprised that the FG essentially stalled 1.012. You are correct, lots of potential alcohol was not made available.

My intention is to do separate stripping runs for each batch and stop at 10%. Then measure the result -- that should tell something regarding the two different batches. The stripping run will tend to separate the alcohol component for further processing by the spirit run. The volume of the stripping runs, if stopped at the 10% ABV mark, will give a measurement of the batch results -- I hesitate to call it efficiency.

If someone else has a different approach let me know -- this is an experiment after all, and I can adjust my approach.

[Oystercracker123]

Mr beer, what is the variable you are testing in this experiment? What do you expect to learn from the stripping of the wash volumes? I have a boatload of questions on ylay, mainly revolving around how it is working and exactly what it is doing.

[howie]

Mr beer, what is the variable you are testing in this experiment? What do you expect to learn from the stripping of the wash volumes? I have a boatload of questions on ylay, mainly revolving around how it is working and exactly what it is doing.

i think because the YA doesn't give us any gravity points, maybe the volume of low wines produced by a strip of identical washes can give us an idea of the efficiency of YA, compared to us-05.
i have seen a increase in low wines when using YA in comparisons.

[Oystercracker123]

I would agree if the washes were identical other than the ylay vs us05. The problem is the stated variable was solely the yeast and multiple others have been introduced.

[The Booze Pipe]

To answer NormandieStill: The difference in volume was the measured low wines after fermentation was complete in a 20 galon HDPE container. Same recipe -- 15 gal water and 40 pound of corn. Ferment on grain. Volume of the batch was measured at 19 gallons starting.

Drain and squeeze. Transfer the liquid from the container to settling carboys using aquarium pump -- very easy to get accurate measurements. Obviously the trub was left in the fermentation containers and discarded.

YLAY batch resulted in 13.95 gallon after transfer
US-05 batch resulted in 11.1 gallon after transfer

Is this a confusion of terminology? I believe you are referring to clear beer here? Low wines come after the first distillation not fermentation.

[Mr_Beer]

I apologize -- my newbie status certainly does not make me an expert on terminology.

I used the incorrect term, thank you for your correction.

Armed with that knowledge, I will now spend the morning changing my software to properly enumerate the correct terms.

[Mr_Beer]

As promised here is a summary of my Angel Yeast versus US-05 side by side experiment.

Nothing definitive but my bias shows through.

Angel Yeast
15 Gallon Water, 40 pounds corn crushed to almost corn meal consistency, ferment on grain.
Draw tap water at 98℉ -- anticipates temp drop when grain added to reach 90℉.
Added angel Yeast and stirred gently
Heat belts – two each 85 watt belts with controller to maintain heat at 89℉
Stirred three times per day for first three days, then occasionally after that.
Removed grain and drained when FG was .998.
Clear beer volume available for stripping was 12.75 gallon.
Low Wines available for processing, after a 1.5% discard of foreshots, was 3.36 gallon – stopped processing at 10% ABV

Time spent mashing was about 15 minutes.
Fairly quick fermentation – promoted by use of heat belts most likely.
No cleanup activity
41% more Low Wines available for processing


US-05 Yeast
15 Gallon Water, 40 pounds corn ground fairly fine, ferment on grain.
Water heated to 195℉
Stirred in 40 pound corn – crushed to almost corn meal consistency
Added 2 tbls SebStar HTL (High Temp) enzyme
Let temp drop gradually – 6.5 hours to 133℉
Added 3.5 tbls SEBAml GL (Low Temp)
Waited 4 hours and iodine starch test showed converted
Left overnight in covered mash pot.
Temp was 118℉ even though it had set overnight.
After stirring an iodine starch test mixture indicated it was not converted
Inserted cooler and lowered temp to 82℉.
Hydrated US-05 yeast and pitched because of fear it was starting to ferment
Removed grain and drained when FG was 1.012 – conversation not as expected.
Clear beer volume available for stripping was 11.1 gallon.
Low Wines available for processing, after a 1.5% discard of foreshots, was 1.994 gallon – stopped processing at 10% ABV

Elapsed time spent mashing was about 25 hours
Extended fermentation time
Lots of cleanup activity
Additional expense of enzymes
41% less Low Wines available for processing.

At this point my observation is that

Angel Yeast makes the mashing process falling down easy. It eliminates a 24 hour mashing process and the need for enzymes and energy to heat up the mixture. Essentially, Angel Yeast eliminates the multi-step process of mashing in favor of simplicity. Easy to understand why they are gaining commercial market share in the EU and Asia.

Angel Yeast eliminates the need for enzymes – a cost savings and a process advantage.

Amazon pricing for 500 gram package -- Angel Yeast $23 and US-05 costs $79. Angel Yeast requires about 15% more yeast (by volume). By all standards Angel Yeast is half the cost.

Most commenters indicate that Angel Yeast is neutral (taste wise) relative to the finished product. Some commenter indicate that the grainy flavor is preserved.

Angel Yeast was (apparently) difficult to obtain in the past; depending on how things go with China it may become difficult to obtain in the future.



Unless there is a major surprise when the taste evaluation is complete, my mashing process will change for corn based bourbons and whiskeys. I intend to research for all barley based recipes. My expectation is that the results will be similar.

I may try an all wheat mixture next.


I will report back in a couple of months regarding taste.

[MooseMan]

Thanks Mr_Beer for the final write up.

I'm a YLAY convert already and I too can only find positives to using it.
I haven't used a pure (No extra enzymes, malt only) mash process since I stopped hardcore beer brewing around 4 years ago, but I'll never get all the BIABIAC kit out again.

I'm planning a barley/oat batch next myself.

[Mr_Beer]

The actual final write up is at

viewtopic.php?t=93242