ASBC Member? Iodine Rxn
- Thread starter Blue-Frog
- Start date
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Forget the iodine test. Just monitor the SG of the wort in your mash. When it stops increasing with time, the mash is done. As a bonus, by monitoring the mash SG you can determine your conversion efficiency.
Brew on
Brew on
I agree. The iodine test is truly worthless since it only indicates if the starch has been converted and not to what types of sugars they have converted to. The only reason starch would not convert, is if the grist had some weird adjunct content or insufficient base malt content. An all malt grist with significant base malt content WILL fully convert.
Provided the diastatic potential is there.
This is not to say I do the test. Yes, I have bottle of tincture of iodine I bought for the purpose 30 yrs ago but I'd be hard pressed to find it.
I'm also a member of ASBC but not sure what that has to do with it.
And to answer the question one puts a drop of liquid on a white porcelain surface and a drop of iodine solution next to it. When they spread and touch there will be discolouration unless the starch has converted. Even a 200 SRM wort has but 5 SRM-cm color depth in an 0.5 mm thick layer of wort.
This is not to say I do the test. Yes, I have bottle of tincture of iodine I bought for the purpose 30 yrs ago but I'd be hard pressed to find it.
I'm also a member of ASBC but not sure what that has to do with it.
And to answer the question one puts a drop of liquid on a white porcelain surface and a drop of iodine solution next to it. When they spread and touch there will be discolouration unless the starch has converted. Even a 200 SRM wort has but 5 SRM-cm color depth in an 0.5 mm thick layer of wort.
Blue-Frog
Well-Known Member
Mabrungard, In my case, knowing if all the starch has converted is indeed the very question I want to answer... not what types of sugars it (they?) have been converted to. (Well that would be even better I guess, but for now I just want to know there is nothing more to be gained by extending the mash duration.)
doug293cz, Previously, I was unable to measure higher gravity directly in the wort, but I can now. So from here on out I should be ok; it seems the conversion was quite quick and over before I was expecting it to be.
Ajdelange, ... ... ha! just as I was about to explain my reasoning for mentioning the ASBC - the answer you provided to me became clear... it just took a few seconds!
I will try using a slide/coverslip arrangement and see if that works.
Thanks!
doug293cz, Previously, I was unable to measure higher gravity directly in the wort, but I can now. So from here on out I should be ok; it seems the conversion was quite quick and over before I was expecting it to be.
Ajdelange, ... ... ha! just as I was about to explain my reasoning for mentioning the ASBC - the answer you provided to me became clear... it just took a few seconds!
I will try using a slide/coverslip arrangement and see if that works.
Thanks!
Usually a white dinner plate will do.
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Blue-Frog
Well-Known Member
OK will try that with a coverslip. But with just a plate, I haven't been successful in reducing the darkness of the wort from interferring with my ability to eyeball rxn color.
Curiousity about the MOA Beer Method #7B, for dark beers,
(and whatever the MOA might say about dark worts in the wort section) promted my question.
Curiousity about the MOA Beer Method #7B, for dark beers,
(and whatever the MOA might say about dark worts in the wort section) promted my question.
Yes, that's pretty clear now. In support of what others have said we note that MOA 7A and 7B are 'archived'. That means they are no longer in use. You can still dig them out but it's not so easy.
