Starch Conversion question

[Milwaukeebum]

Hello All,

Here is what I did:
On a white plate a added a couple of drops of wort. Let it cool.
I add a drop Iodophor
The drops look dark brown/Black then turns tanish color. Is that a conversion?

How do you do a starch conversion? Do you use iodophor for testing? Does anyone have a Pic with a proper conversion.

thanks

[corkybstewart]

If it turns blue I think there is still unconverted starch. If it stays tan or brown, everything is converted.

[takhsh]

Although it is a simple test, most of the people I know they do not do it.
Why?
Probably because they are successful without doing it.
However, I thought of a way of doing it, without really reading or asking people to let you what are the colors.
Right after you mixing your grain with water, you know there is a lot of starch. Right? Pick up a little of that and put it aside on a plate. After you have gone with sacharization like half way through or so you think pick up another sample. After one hour of sacharization, pick another sample. Now you have three sample. Do the iodine test. See yourself the colors, and let us know too.
As it was said, one expects blue color when there is still starch, brown color if there is no startch. You may find out that after 10 minutes at sacharization temperature there is no starch. But more important you will see with you own eyes the kind of blue, or the kind of brown.
I think, doing this, it is the best way of finding out the actual colors. It is difficult to rely on colors from a picture.

[gallowd7]

When you have fully converted the starches, the drop if iodine should "disappear" into the sample.
I only perform the test when I'm trying out new grains. Once you've done 10 batches using Maris Otter Pale, you don't really need to check every time.

[Otis_The_Drunk]

I use a strait tincher of Iodine, and it it changes color to either purple or brown then you have incomplete conversion.
If it stays the same color as it came out of the bottle, then it is done and time to move to sparging.

[corkybstewart]

Once in a while I test mine, but it's always showed conversion long before my sparge water is up to temp so I quit worrying about. My rule is to mash until the HLT hits 170 and just call it converted. Conversion is probably complete in 20-30 minutes.

[danno]

I've never once tested mine.

[gestyr]

I tried to sample at different times during the mash to contrast colors but my cat drank the samples when my back was turned. :)

[HarkJohnny]

Originally posted by takhsh
Although it is a simple test, most of the people I know they do not do it.
Why?
Probably because they are successful without doing it.
However, I thought of a way of doing it, without really reading or asking people to let you what are the colors.
Right after you mixing your grain with water, you know there is a lot of starch. Right? Pick up a little of that and put it aside on a plate. After you have gone with sacharization like half way through or so you think pick up another sample. After one hour of sacharization, pick another sample. Now you have three sample. Do the iodine test. See yourself the colors, and let us know too.
As it was said, one expects blue color when there is still starch, brown color if there is no startch. You may find out that after 10 minutes at sacharization temperature there is no starch. But more important you will see with you own eyes the kind of blue, or the kind of brown.
I think, doing this, it is the best way of finding out the actual colors. It is difficult to rely on colors from a picture.

great idea there for the new brewers to AG

[Mill Rat]

I did iodine tests at first to calibrate my taste buds. You can taste the starch very easily, and it is noticable in its absence. I tend to keep my sacc rest temperatures on the low side to maximize fermentables, so I still usually do a test to confirm what my taste buds are telling me. It's very simple and cheap, so why not?

[corkybstewart]

Originally posted by Mill Rat
I did iodine tests at first to calibrate my taste buds. You can taste the starch very easily, and it is noticable in its absence. I tend to keep my sacc rest temperatures on the low side to maximize fermentables, so I still usually do a test to confirm what my taste buds are telling me. It's very simple and cheap, so why not?

I can't taste starch when I 'm mashing because that's when Im eating my breakfast of a jalapeno/dijon mustard sauerkraut dog with a half glass of dopplebock.

[SirVeza]

Corky, If your breakfast is that I don't want to invite you over for dinner! But I would appreciate it if you invited me over for breakfast. Hmmm...let's not go there.

Before I used to use a teaspoon of wort and drop a drop of iodine on the edge of the teaspoon. If it blends easily without a "reaction" then that's great. If it goes blackish, brownish, dark purplish, give it another 1/2 hour. It's a basic high-school science. Maybe someone should market "starch-o-strips" or something? Don't laugh, someone retired from Pet Rocks. (Gee how old am I?)

The idodine I use is basic drug store grade iodine antiseptic. If I remember correctly the little brown bottle says like 10% or something. I have never tried iodaphor for testing the presents of starch. Chemically, I think that this would react with the starch in the same or similar way. Iodine is iodine and starch is starch.

Like Mill Rat and others, I take another teaspoon of wort for me to taste. Macaroni water or boiled potato water tastes starchy. You know this from birth, or at least early childhood. :) It's very familiar.

When that thick starchy taste gives way to sweet, yes you are business.

Please, I know this sounds stupid, but for all the learning hombrewers...
DO NOT PUT THE IODINE TEST SAMPLE BACK IN THE WORT!!!

(another "Don't laugh--I've done it before" thing.)

All the best,

Dan
Homebrewing in the Philippines (http://homebrewinghobby.blogspot.com)