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Old 08-31-2007, 09:57 PM   #1
cpbergie
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Default How do to an iodine conversion test?

Can this be done easily with Iodophor?

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Old 08-31-2007, 10:01 PM   #2
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I use tincture of iodine that I picked up at the local grocery store. Don't know about Iodophor though.

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Old 08-31-2007, 10:02 PM   #3
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http://www.realbeer.com/jjpalmer/ch14.html

Quote:
Testing Your Conversion
The brewer can use iodine (or iodophor) to check a sample of the wort to see whether the starches have been completely converted to sugars. As you may remember from high school chemistry, iodine causes starch to turn black. The mash enzymes should convert all of the starches, resulting in no color change when a couple drops of iodine are added to a sample of the wort. (The wort sample should not have any grain particles in it.) The iodine will only add a slight tan or reddish color as opposed to the flash of heavy black color if starch is present. Worts high in dextrins will yield a strong reddish color when iodine is added.
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Old 08-31-2007, 10:06 PM   #4
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I've always used iodopher and never had a problem.

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Old 08-31-2007, 10:45 PM   #5
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yep, iodophor user here too. a few teaspoons of wort runnings, a drop or two of iodophor and mix.

if its converted, the drops bascially disappear. if not converted, the solution will turn almost black.

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Old 08-31-2007, 11:42 PM   #6
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Unless you have really fouled things up, you will always have complete conversion in 40 minutes or so, sometimes less. It is so easy to get a false reading doing the iodine test, it is really a waste of time to even do it.

If you are doing the test in an effort to cut your mash time to an absolute minimum (in the 15-20 minute range), you may get an indication of complete conversion. However, what the test will not tell you is whether the enzymes are done working on the wort. The initial conversion will produce a lot of long chain sugars that are not very fermentable. The additional time (normally an hour total) allows the enzymes to keep working to break down those chains into shorter pieces that the yeast can use. If you do a very short mash with complete conversion, you may end up with beer with a high finishing gravity. If you get a false indication that conversion is not complete, you can end up mashing way too long and getting a beer that finishes too dry.

Forget the iodine test and do a mash of a consistent length at the proper temperature and everything will be fine. There are places to cut the length of the brew day, but the mash isn't really one of them.

Wayne
Bugeater Brewing Company

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Old 09-01-2007, 01:51 AM   #7
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Quote:
Originally Posted by Bugeaterbrewing

----- Forget the iodine test and do a mash of a consistent length at the proper temperature and everything will be fine. There are places to cut the length of the brew day, but the mash isn't really one of them.

Wayne
Bugeater Brewing Company
Some guys like David Miller and some don't. I'm one of the former. Dave says that, depending on the malt type, mash up to two hours and forget about iodine tests. When I took that advise my mash efficency went from about 70% to a concistent 90 to 92%.
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Old 09-01-2007, 03:35 PM   #8
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The iodine test is very helpfull when troubleshooting your process. Tincture of iodine or iodophor will work. Once you have your process down you do not need to check every mash and should as mentioned above be mashing according to time and temp to control your final product.

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