Can I get gravity points that are not sugar?

Did my first partial mash this weekend. After an hour of mashing and monitoring temps I did the iodine test. No matter how long I let my mash sit, the iodine still turned black, meaning there was unconverted starches. Took the gravity reading of my runnings, and it was good. I calculated 65% efficiency, which, from reading here, is good for a partial mash. But that iodine test irks me. Did I get a lot of points from starches, or are gravity points always from converted sugars? Does the iodine test really work, or are there always going to be enough starches to turn the iodine black?

What was the recipe? What was the mash schedual? From what I understand about Partials, most of the sugars come from the non-grain mailt.

2.5 lbs 2 row
4 oz aromatic
4oz biscuit
4 oz vienna

Used 3.5 qts water, strike temp of 168 to get a mash temp of 152. Held it in the warm oven for an hour.

I checked the temp periodically to make sure it stayed in the appropriate range and stirred.

Sparged it by ladeling a gallon of water at 170 over the grains in a colander.

The result was 1.5 gal wort with OG 1.056.

Of course I added water and DME for the boil.

I think my real question is "is the iodine test reliable?" Won't there always be some residual starch to turn the iodine black?

Looking at that again, my efficiency is way off. :cross: But the rest of the question stands.

Lets wait for someone with more experience.... but it looks pretty straight forward... 15-20 minutes should have done the trick.

The iodine test works...you do want to be careful to just get wort and not actual particles (that's how I've read it, anyways). You only need a few drops of wort and a drop of iodine.

Also, do a test at the beginning of the mash to see what unconverted looks like. It is really black/purple. The iodine test can still look sort of dark, but maroonish in color, after conversion. Could this have happened, or was it really black/purply?

The grist you have listed should definitely have converted, and I would say in easily less than an hour. Have you calibrated your thermometer? Any chance you were significantly cooler or warmer than you thought?

Did you crush the grain or did you buy it crushed?

I have found that dipping a corner of a paper towel in the mash and doing the test on that gives good results. No particles and a nice white background.

I remember hearing someone say that you could use Iodophor for this test; is that the case, or do I need to snag some regular iodine?

Yes, I know, dumb question....

I think you got it. I tried at the beginning and it was a real quick reaction. Later, it still turned black, but it took a little longer, and wasn't as dark. Experience really counts for something in this hobby. I could have been mashing forever and probably never passed the iodine test the way it is written. I was waiting for a definitive pass/fail. Thanks.

Chairman Cheyco said:

I have found that dipping a corner of a paper towel in the mash and doing the test on that gives good results. No particles and a nice white background.

Click to expand...

That is a good Idea. I have also heard about performing the test on chalk. But a paper towel seems cheaper and more readily available.

Yes, the mash should have converted. The only think that is unknown is its PH. It could be out of range for conversion if you have hard water. Any info on the water you used?

Kai

I like the towel trick.

OP - the starch conversion should be complete after 30 minutes and the test is reliable. But, it's a lot like pH strips, hard to read. I think I'll try the towel trick next time, myself.

You can get points from starch & proteins.

I bought the grain crushed. I don't have a mill, yet... Ka-ching!!

My water is well water that runs through a softener, so it is very soft. It's worked OK for all extract recipes, so I'm not going to fret over it just to get slightly better PM results. Maybe when I go to all grain I'lll take a look. It's not worth the time right now.

Kaboom said:

I bought the grain crushed. I don't have a mill, yet... Ka-ching!!

My water is well water that runs through a softener, so it is very soft. It's worked OK for all extract recipes, so I'm not going to fret over it just to get slightly better PM results. Maybe when I go to all grain I'lll take a look. It's not worth the time right now.

Click to expand...

Next time you do a partial mash, try bottled water for the mash part and see if you get conversion with that. I'm not sure what affect the water softener has on the residual alkalinity of the water.

Kai

Most softeners are ion exchange and remove calcum and magnesium, but to do so add sodium to the water, which can lend some pretty crazy flavors. If it works it works I 'spose. Let us know how it comes out!

Matt

Chairman Cheyco said:

I have found that dipping a corner of a paper towel in the mash and doing the test on that gives good results. No particles and a nice white background.

Click to expand...

The towel trick is cool, but you have to be careful that the paper doesn't contain any starches. I seem to remember a high school chemistry class where we tested household items for starch using iodine, and some types/brands of paper turned the iodine black.

Let your sample cool, as it should anyway. If there are no grain particles in your sample you should see redish to yellowish colours.