Spike Brewing 12.5 Conical Fermenter Giveaway!

Home Brew Forums > Home Brewing Beer > All Grain & Partial Mash Brewing > iodine test for starch converstion in AG batches

Reply
 
LinkBack Thread Tools
Old 03-07-2006, 08:02 PM   #1
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,235
Liked 72 Times on 64 Posts
Likes Given: 11

Default iodine test for starch converstion in AG batches

This is a verbatim PM I sent to BeeGee. He has a theory, but isn't sure if it's the Right Answer, so I'm throwing this to the wolves....

I've been putting more and more thought into AG brewing, and one thing I don't understand is the iodine test.

I know the basics.... if iodine touches starch it turns black, so you use iodine to see if you have converted the starch to sugar. (right?)

If so, how the hell do you ever get a NON-black test result with efficiency under 100%? If you haven't converted all the starch to sugar, won't the iodine always turn black??

Remember.... I know jack sh!t about AG brewing, but this is something I've been wondering about.

-walker
__________________
Ground Fault Brewing Co.

Last edited by Walker; 03-07-2006 at 08:05 PM.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 08:05 PM   #2
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,235
Liked 72 Times on 64 Posts
Likes Given: 11

Default

after another message from Billy, I think I might be confused about the term "efficiency".

Is that describing the conversion of starch into sugar, or is it describing the extraction of the sugar form the grainbed? (ie; ALL starch converts to sugar, and effeciency is a measure of how much of that sugar you extracted into your kettle.)

AG retard,
-walker

__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 08:14 PM   #3
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 114 Times on 71 Posts
Likes Given: 4

Default

Quote:
Originally Posted by Walker
(ie; ALL starch converts to sugar, and effeciency is a measure of how much of that sugar you extracted into your kettle.)
You got it.

I have actually come across multiple definition of efficiency:

(extracted sugar) / (maximum extractable sugar) and
(extracted sugar) / (amount of grain used)

The latter seems to be common in German brewing literature and is called Sudhausausbeute (brew house efficiency). And yes wre have pretty long words in German.

Kai
Kaiser is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 08:16 PM   #4
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,235
Liked 72 Times on 64 Posts
Likes Given: 11

Default

ok. thanks for clearing that up.

The yahoo's can take this thread and run it into the weeds now.

-walker

__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 08:20 PM   #5
Lou
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2006
Location: Chicago, IL
Posts: 623
Liked 14 Times on 6 Posts

Default

Quote:
Originally Posted by Walker
The yahoo's can take this thread and run it into the weeds now.

yes! my time to shine!!!

i think enzymes are a government conspiracy!!! they're not real!!!!!
__________________
Lou is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 08:24 PM   #6
Walker
I use secondaries. :p
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Walker's Avatar
Recipes 
 
Join Date: Sep 2005
Location: Cary, NC
Posts: 11,235
Liked 72 Times on 64 Posts
Likes Given: 11

Default

Quote:
Originally Posted by King Kai
yes wre have pretty long words in German.
Yes, you do, but the beauty is that you can almost always create the word you need (if you don't know the 'proper' word) by stringing together a bunch of small words that you DO know to get your point across.

That's what I LOVE the german language.

For those of you who think German is a guttoral, spit-filled language.... you obviously have never heard much DUTCH spoken.
__________________
Ground Fault Brewing Co.
Walker is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 08:34 PM   #7
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 114 Times on 71 Posts
Likes Given: 4

Default

Quote:
Originally Posted by Walker
Yes, you do, but the beauty is that you can almost always create the word you need (if you don't know the 'proper' word) by stringing together a bunch of small words that you DO know to get your point across.
We definitely have many concatenated words for which the English language has just a single word. But the concept of concatenated words is not foreign to English either, but there you keep a space between the words, which doesn't make the word look like one long word.

Kai
__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator
Kaiser is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 09:00 PM   #8
Baron von BeeGee
Beer Bully
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Baron von BeeGee's Avatar
Recipes 
 
Join Date: Jul 2005
Location: Barony of Fuquay-Varina, NC
Posts: 5,419
Liked 10 Times on 10 Posts

Default

Iknowwhatyoumean.

__________________
Baron von BeeGee is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 09:05 PM   #9
Baron von BeeGee
Beer Bully
HBT_LIFETIMESUPPORTER.png
Feedback Score: 0 reviews
 
Baron von BeeGee's Avatar
Recipes 
 
Join Date: Jul 2005
Location: Barony of Fuquay-Varina, NC
Posts: 5,419
Liked 10 Times on 10 Posts

Default

Oh yeah...just for my edification. So we're saying that all starch gets converted to sugar if the iodine test is negative, but the efficiency is measuring how well you lauter the mash? Is poor efficiency then attributable to factors such as bits of converted starch getting stuck inside uncrushed/poorly crushed grains, just not getting sparged into solution, or get missed due to water channelizing and missing them?

__________________
Baron von BeeGee is offline
 
Reply With Quote Quick reply to this message
Old 03-07-2006, 09:28 PM   #10
Kaiser
Feedback Score: 0 reviews
 
Kaiser's Avatar
Recipes 
 
Join Date: Nov 2005
Location: Pepperell, MA
Posts: 3,904
Liked 114 Times on 71 Posts
Likes Given: 4

Default

Quote:
Originally Posted by BeeGee
Is poor efficiency then attributable to factors such as bits of converted starch getting stuck inside uncrushed/poorly crushed grains, just not getting sparged into solution, or get missed due to water channelizing and missing them?
yes, and 100% efficiency would not be goo since you have to do so much sparging, that you get tannins from the husks.

One of the parameters that are measured for malts are fine grain extract and coarse grain extract. For fine grain extract the malt is ground to flour, mashed to full conversion and then all the solid are removed. The extract is measured and expressed as % of the initial grain weight.The same is done for coarse grain extract, but here the malt is just crushed. This all is done in a laboratory setting.

here is malt info from a German maltster (Durst Malz): http://www.durstmalz.de/pilsnermalt.html

There you see Fine Grind extarxt and Fine Grind / Coarse Grind difference.

Kai
__________________
BrauKaiser.com - brewing science blog - Twitter - water and mash chemistry calculator
Kaiser is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
iodine test, where to buy suitable iodine? nathan All Grain & Partial Mash Brewing 7 04-26-2010 12:58 PM
Iodine starch test? pnj General Beer Discussion 5 05-11-2009 12:44 AM
Starch To Sugar Iodine Testing Question.. LIVETOBREW All Grain & Partial Mash Brewing 6 03-01-2009 12:52 PM
Starch test Bob869007 All Grain & Partial Mash Brewing 3 01-06-2009 04:38 PM
Starch test? Jeepsn beer All Grain & Partial Mash Brewing 9 11-22-2006 08:13 PM