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Old 08-13-2009, 02:55 PM   #1
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Default Iodine test

Can anyone give me the how to do and what to expect?

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Old 08-13-2009, 03:07 PM   #2
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The iodine test is to see if the starches in the mash have fully converted to sugars. After the mash period, spoon out a small portion of the liquid and place on a plate. Then put a drop of iodine next to the mash liquid and mix together loosely with a spoon. If the iodine color turns purple then the mash is incomplete and there is starch present. If the iodine doesn't change color then the conversion is complete.
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Old 08-13-2009, 04:15 PM   #3
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here is some info and pictures: Starch Test - German Brewing Techniques
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Old 08-13-2009, 10:23 PM   #4
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and a lot of people skip the conversion test for these reasons:

1. today's modified malts have great diastatic power, and many times fully convert in 30-45 minutes, so 60 mins guarantees conversion

2. any tiny particles of grain are likely to turn black during the test, giving you the false reading that conversion hasn't completed yet

people here, or your LHBS should be able to clue you in to which base malts aren't well modified and might be quirky about converting.
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