[bierview]

Middle of my mash  7* Vienna, 3* Flaked corn, 1* L. Munich.  After 60 minutes at 150 degrees and 10 minutes at 168 degrees, still coming up black on the iodine test.  Tasted wort and it's sweet.  Any quick opinions.  Gotta move forward on this.

Thanks

[Wort-H.O.G.]

Middle of my mash  7* Vienna, 3* Flaked corn, 1* L. Munich.  After 60 minutes at 150 degrees and 10 minutes at 168 degrees, still coming up black on the iodine test.  Tasted wort and it's sweet.  Any quick opinions.  Gotta move forward on this.

Thanks

take hydrometer or refractometer reading and see if you are on target...likely all is well assuming you thermometer isn't way off.

[euge]

Is that test even 100% accurate/reliable?

Likely that the mash converted.

[bierview]

I'm sparging and will check my mash efficiency.  Thing is........I've never experienced this before.

Thanks for the encouraging words.

BV

[Wort-H.O.G.]

Is that test even 100% accurate/reliable?

Likely that the mash converted.

no idea. i've never done one.

[euge]

The corn is 37.5% of the bill. That shouldn't have been too much for the Vienna and Munich to convert. Pushing it perhaps. If anything, next time mash longer?

And what was your water-grain ratio?

[bierview]

Water to grain ratio.........1.35 per pound

[bierview]

1.35 qts.

[euge]

That's not out of the realm of acceptable ratio but it *Might* have affected the adjunct mash. A lot of us shoot for a thinner mash in the 1.6-2.0 quarts range.

[Stevie]

Iodine tests are basic chemistry and very reliable. If your mash is well mixed and there is starch, the iodine turns black. That said I don't use them.

Too many adjuncts for the diastatic power of the Vienna. Vienna is only 50°L and most sources say 40°L is the minimum required for self conversion. That means it could barely handle its own starches before you threw 28% flaked corn in the mix.

[coolman26]

Agree with Stevie +1


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[euge]

Ya I didn't add the corn to the bill before calculating the percentage. It's only a little better at 27%. My bad.

What sort of beer is this supposed to be? A cream ale or classic american pils? That is a lot of corn.

[dmtaylor]

Just because you still have a little starch in there doesn't mean conversion isn't "good enough".  Your beer will most likely turn out fine.

As for reasons why, could be just that the Vienna and Munich base malts have fewer enzymes due to the darker kilning process.  If you had used a pound of Pilsner malt as well then we might not be having any discussion.  But like I say, regardless, I think it's going to turn out fine, probably, assuming your mash thermometer is accurate.

[kramerog]

Iodine tests are basic chemistry and very reliable. If your mash is well mixed and there is starch, the iodine turns black. That said I don't use them.

Too many adjuncts for the diastatic power of the Vienna. Vienna is only 50°L and most sources say 40°L is the minimum required for self conversion. That means it could barely handle its own starches before you threw 28% flaked corn in the mix.

MFB Vienna exceeds 100°L, but I agree that the diastatic power of the Vienna used is the first suspect.

[bierview]

Well........lesson learned.  But I did run this grain bill by the group last week and no one said don't do it.  The only advice was to use a fair amount of hops to balance the Vienna.  What can I expect to happen in the fermenter?