Dies your mash fully convert?

[Codfishhead]

Thought mine did. That was until I did an iodine test after the first runnings.

As a former Configuration Manager I'm a process guy. Track everything to repeat what's good and change what's not. So I like to test at all points.

After my first runnings I took a sample and did an iodine test. Yellows n orange. All starches converted. Added hot stirred it up and recirculated. Took another sample n find starches not converted. Iodine turned dark.

There was still starches that had yet to convert that we're loosen up after the mixing.

Anyone else finding this?

My grains were very well crushed. I recirculated for a lot of the 60 min mash.

How could heat not get to all the starches?

I check for starch conversion at 30 mins and it was converted. I'm thinking of doing 2 30 min mashes instead of one 60 mins then a rinse.

Thoughts?

 

[billl]

I'd say you aren't measuring nearly enough. Iodine tests only tell if there is starch in solution in the sample. It doesn't tell you if you got all the starch out of the grain. You should measure the mash gravity to confirm that.

If you aren't getting full conversion (or near it) in 60 minutes, you should look at your crush to make sure it is fine enough. Otherwise, you should mash longer, not shorter.

 

[Codfishhead]

Thx Bill

Maybe I’m not stating it correctly.

Here’s my process.
Grain was very well crushed. I take samples at every stage and record them. 11lbs of grains held at 122 for 18 mins, turn burner on and recirculate until temps hits 153. Turn down burner and hold 153 while recirculating for 60 mins. Take sample of first running that showed all starched converted. Gravity of sample at 1072.

Add in the rest of the sparge water at 200 degrees and stir. Recirculate till clear before drawing off. Take sample that read 1022 from second runnings. Do another iodine test and find dark colors which tells me starches are still present.

So how after a total of an hour and a half at temps does it still show starches not converted when they showed fully converted in the first runnings? Even if there was a dry ball (which there def wasn’t) how does that starch not convert while in the proper temp for that amount of time?

 

[billl]

"So how after a total of an hour and a half at temps does it still show starches not converted when they showed fully converted in the first runnings?"

You are misinterpreting your test results. A negative iodine tests does not mean "fully converted". It means "no detectable starch levels present in solution". If the starch is still locked in the grain, you'll get a negative test, but that doesn't mean its fully converted.

In order to get conversion, the starch needs to gelatinize and flow out into the water. The finer the crush, the easier that happens. There are also other enzymes in play that help break down cell walls and proteins that may be locking those starches inside. If you mechanically stir, you can also physically break apart grain particles and expose more starch.

Unless you've got a pretty thin mash, 1.072 means you weren't fully converted. The table on the link below shows maximum wort gravity for first runnings based on mash thickness.

http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency

 

[Codfishhead]

Thx much Bill.

I didn't think the starches could hide from the moisture and heat. Very good read by the way.

I crushed a little more grain to take a close look at every piece. The grain is crushed perfectly if the goal is to crack open the grain to expose the sugars while keeping the hull in the largest pieces possible. After looking over the cracked grain I think the problem may be the large chunks of flour/sugar are not getting penetrated hence leaving the starches inside intact. Really the only place I think starches could hide.

I’m going to experiment with the next few mashes. I’m thinking of a small grind along with stirring several times during the process.

Also wondering about timing. If when I checked after 30 mins and saw no free starches why shouldn’t I draw that off into the boil pot. Then put more 153 degree water in to let the second sparge sit and convert for a half hour?

Are there any significant changes that happen to the grains between 30 and 60 mins? Any good reason the grain needs to sit for an hour at temp if it converts in a half hr?

 

[The Pol]

You could experiment with conditioning your malt prior to crushing, and reducing your mill gap. Same husk quality, finer crush.

 

[wobdee]

Is your iodine test sample free of particles or grain debris? I've read that this could skew the results. Try filtering sample through a coffee filter before testing.

 

[nutty_gnome]

I didn't see the particulars of how you tested... but don't do the test on a paper plate or a piece of paper (paper reacts as a starch).... use white china, chinette or something white and nonreactive.

 

[Codfishhead]

You could experiment with conditioning your malt prior to crushing, and reducing your mill gap. Same husk quality, finer crush.

Please explain what "conditioning your malt" is?

Wobdee it's clear as can be. I have the mash recirulating and take samples prior to drawing off. Not grain particles at all. But I'm thinking now I need to do both. Check the liquid and the solids.

 

[The Pol]

It is the process of adding water, about 2% of the malt bill, by weight, to the grain prior to crushing. I usually do this by misting it with an atomizer. Let it soak in for about 5 minutes, then crush. A 10lb malt bill would require 3oz of water, by weight.

This rehydrated the husks slightly, allowing a much finer crush, without crushing the husks. It allows a finer crush, better conversion, without the side effect of ruining your filter bed.

 

[billl]

"Also wondering about timing. If when I checked after 30 mins and saw no free starches why shouldn’t I draw that off into the boil pot. Then put more 153 degree water in to let the second sparge sit and convert for a half hour?

Are there any significant changes that happen to the grains between 30 and 60 mins? Any good reason the grain needs to sit for an hour at temp if it converts in a half hr?"

The vast majority of the enzymes flow easily into the water/wort. If you drain the wort, you get rid of your enzymes.

There is no magic cutoff point at 30 or 60 minutes in terms of what is happening to the grain. Hot water is slowly being absorbed into the grain and starch is being liberated. It's not linear though. Near the grain surface, you've got lots of water per starch and lots of movement. As you move into the grain, you get less water, less movement, and much slower everything. You would get very fast conversion by grinding the grain into flour, but it wouldn't drain worth a darn. You need to walk that fine line between crushing fine enough to get reasonably fast conversion but not so fine that you make mud. If you take gravity measurements along the way, you can see how the process plays out. eg gravity readings at 30, 45, 60, 75, 90 to see how your system is really performing.

If you got 100% starch conversion in 30 minutes, the mash would still be active. Not all sugar is created equal. You get a mix of larger sugars and simple sugars. The enzymes will continue to break down the larger sugars into smaller sugars until they denature. 60 minutes is just a general baseline for "average" mashing temps creating a reasonably fermentable wort.

 

[Codfishhead]

Thx Pol. That’s new to me. Makes sense to soften up he hulls by adding water. Make them less brittle which in turn I think would make them bend more instead of break and shatter into much smaller pieces. I’ll def give that a try as well.


Thank you Bill. Very much appreciated.

I think I can have the best of both worlds by stirring the mash a few times during the first half hr. Check to see that all the free starches have converted. Once I see that say in a half hr I drain off into the boil pot. Keep the temp in the boil pot at 153 to continue to break down the chains on the first runnings. Add the rest of my sparge water onto the grain and stir it up until ready to draw off. again stir during and test to see when all is converted.

This way I draw off the converted starches/sugars and still hold them at temp to continue the breaking down of sugars chains while introducing fresh water into the mash to free up and convert whatever is left in the mash while holding temp there as well.

Believe it or not when I was brewing 25 years ago I actually knew this stuff. Wife and 4 kids did a number on me I guess. :cross:

 

[billl]

I would not drain the tun until you know conversion is complete. You would be draining all the enzymes.

 

[Codfishhead]

Wouldn’t they still be present in the grain and come out when introducing the new sparge water?

 

[billl]

Wouldn’t they still be present in the grain and come out when introducing the new sparge water?

Sure - in small quantities though. The enzymes are much smaller molecules than those starches and tend to get into solution much easier. They will be uniformly distributed in the wort. If you drain the tun of 90% of the wort, you get rid of 90% of the enzymes.

 

[ABVIBUSRM]

Dont quote me but im pretty sure no gets 100% conversion probably more around 80%

 

[billl]

Dont quote me but im pretty sure no gets 100% conversion probably more around 80%

Of course people get 100% conversion (or darn close - I'm always 97%+) Of course that is total conversion of starch, not total conversion of everything making up the mass of grain. Depending on the lot, base malt is about 80% starch/sugar. eg 1 lb of fully coverted base malt gives the same amount of fermentables as if you had dissolved 0.8lbs of table sugar in your mash.

 

[ABVIBUSRM]

Of course people get 100% conversion (or darn close - I'm always 97%+) Of course that is total conversion of starch, not total conversion of everything making up the mass of grain. Depending on the lot, base malt is about 80% starch/sugar. eg 1 lb of fully coverted base malt gives the same amount of fermentables as if you had dissolved 0.8lbs of table sugar in your mash.

i stand corrected..you know how i test for conversion? if the bubbles have a rainbow sheen and the wort has a slick stickyness it converted

 

[Codfishhead]

i stand corrected..you know how i test for conversion? if the bubbles have a rainbow sheen and the wort has a slick stickyness it converted

That is my old school way as well. Bubbles tell all.


I'm going to test a few methods using the exact same grains and see what comes back.

thx Bill you're a big help.

 

[VladOfTrub]

Moisture, nor hot water liquifies starch. Alpha amalase liquifies starch. There is a thing in the make up of malt called hard starch. It is heat resistant to a point and enzymes will only very slowly convert the starch at conversion temperature.
Heat above 168 will burst hard starch. When the starch bursts, amylopectin is released. That's the stuff that causes mash to jell. When mash out water is dumped into the main mash, enzymes thermally denature, hard starch bursts, amylopectin is released and there are no enzymes left to convert the amylopectin. The final product will not be stable and the shelf life will be reduced.
Mash out came from the tri-decoction method where mash is boiled a couple of times and the starch is converted during the different rest periods. Very little unconverted starch gets to the lautertun.

Depending on how high the mash temperature was before and during final sparge and depending on the recirc time length. Maybe, some amylopectin was released and showed up in the test as black. The enzymes were wiped out and the starch didn't convert. If the iodine sample was deep red mahogany or reddish brown, conversion took place. The final product will contain limit dextrins. That's not a bad thing. But, this is a bad thing. Tannin can be extracted if mash pH isn't right and when mash temperatures climb above 172F.

 

[Codfishhead]

Thank you Trub.
Very well explained.

Stir and recirculate for an hour. Drain off and refill with 169 degree sparge water. Stir, recirculate, and drain. I'll test gravity as well as the iodine text along the process.

Basically what I've always done minus knowing why I was doing it.

I was thrown off by think all was converted then seeing dark iodine reading from final runnings.

I'll be brewing a Choc Porter Friday night.

 

[Codfishhead]

I’m reading up on the conversions process in particular the enzymes. Seems there are a lot more Enzymes in grains that have been toasted. Say more in Crystal than pale and much more in Choc and Blacks than all others. Also comes out much easier in the more toasted grains. Which is leading me to do testing by not adding the darker grains to the mash up front. I’ll do the first run minus the dark grains and add them after the first running to help with quickly breaking down and help converting the starches left deeper in the grain.

Any thoughts on this?


Lots of good info here. http://braukaiser.com/wiki/index.php?title=Enzymes

 

[billl]

I’m reading up on the conversions process in particular the enzymes. Seems there are a lot more Enzymes in grains that have been toasted. Say more in Crystal than pale and much more in Choc and Blacks than all others. Also comes out much easier in the more toasted grains. Which is leading me to do testing by not adding the darker grains to the mash up front. I’ll do the first run minus the dark grains and add them after the first running to help with quickly breaking down and help converting the starches left deeper in the grain.

Any thoughts on this?


Lots of good info here. http://braukaiser.com/wiki/index.php?title=Enzymes

You've got it completely backwards. Dark roasted malts have no active enzymes. Heat destroys enzymes. The hotter and longer you roast, the less enzymes are left.

On the flip side, the roasting and crystal process converts much of the starch, so you don't need enzymes to convert that portion. That is why you can steep crystal or chocolate for an extract batch without worrying about conversion.

 

[VladOfTrub]

Enzymes such as dextrase, maltase and phytase are kilned out of modern malt. The first two are debranching enzymes and the third, creates phytic acid and myo-inositol. Chit malt is an enzymatically rich malt. It is tough to work with on its own. It is a great malt that works well in tri-decoction recipes.
You are using a limited step mash process. Basically, one set conversion temperature is used and a set length of time is used for conversion. Take a look at the recipes on Weyermann's site. The recipes are based on the step mash method. They are nice people and if you e-mail them with a question or about a style you'd like to brew, they will help you.

If you are set on the 2nd mash out flush. Before dumping in the 170F water. Add some two row pale malt and brewing water adjusted to 5.3 pH and allow the entire mash to convert. Then do the 2nd flush.

Enzymes don't break down larger sugars into smaller sugars. In the make up of malt are two things of concern to a brewer, amylose and amylopectin. Amylose is a long starch chain and amylopectin is a long starch chain with many branches. Alpha enzyme slices the long starch chain at 1-4 links. When that takes place, a reducing end and a non reducing end are formed. The non reducing end is glucose. Beta cuts off two molecules of glucose from the non reducing end and combines them with a water molecule and the fermentable sugar, maltose is formed. After beta denatures, alpha will continue to form non-fermentable sugar until denaturing. When the enzymes aren't able to convert amylopectin any further than Mother Nature allows, A-Limit and B-Limit dextrin forms. Limit dextrin and protein are responsible for body and mouthfeel.

 

[Codfishhead]

You've got it completely backwards.

SOB!
I even took notes. Guess reading while drinking in the hot tub wasn't the best way to gain knowledge.

Already had several testing experiments planned that I now know would have been a total waste of time. Thank you gentlemen for turning me in the right direction.

So for the last 2 hrs I've been searching and reading up. Lots a science info on mashing. I'm learning all the diff stages at diff temps for diff results. I think this info will be invaluable when targeting certain style beers. It will be nice to fine tune exactly what I'm trying to archive in a beer.

Really could use one of you guys as a neighbor. Would save me a lot if time researching if I had a mentor living next door.

Thx again guys. HUGE help.

Any conversion tips for my Choc Porter that is getting brewed tonight?

 

[billl]

"Any conversion tips for my Choc Porter that is getting brewed tonight?"

Add hot water. Relax and drink a beer. Take measurements after an hour. If it's not done yet, grab another beer.

Yes, there are lots of technical things going on, but 99% of the time you really don't have to worry about them. If you are feeling really ambitious, take gravity measurments every 15 minutes and let the mash run for at least 90 minutes. That will show you a full curve of what the conversion timeline looks like for your system, water, temp, and crush. If you want to start tweaking your process, you'll have a baseline to compare against.

 

[helibrewer]

Remember that iodine only indicates for the amylose conversion, not amylopectin. That is one reason to not stop your mash when the test is negative, i.e. at 30 minutes.

What is your mash ratio, how many quarts of water per pound of grain are you using?

A refractometer is a great tool for monitoring conversion during the mash.

 

[Codfishhead]

Bill checking gravity is in the process at many steps now.

I know I go over board and have a need to know more than is necessary but that helps me understand the WHY’s. Knowledge is power.


Now how do I speed this day up so I can run from my office to my brew house?