...or until starch conversion is complete

[Beestin]

I'm new to all grain. Seeing recipes with "mash for 1 hour ...or until starch conversion is complete". How do I know when starch conversion is complete? Is there a way to test?

 

[aiptasia]

Yes, you can definitely test for mash conversion using iodine and a paper plate. Put a little mash water on the plate (like a teaspoon or so) with no grain in it and let it cool down to room temperature. I just fan it off with another paper plate to get it to cool off. Then, put a few drops of household iodine (tincture of iodine) into the mash water. If the mash water is a lighter yellow/amber, you have good conversion. If it's dark purple to black, keep mashing 15-20 minutes more and then re-test.

Source: http://byo.com/pilsner/item/1435-successful-mash-conversion-tips-from-the-pros

 

[RM-MN]

Why, yes there is. Take a drop of wort that you produced and a drop of iodine. If there is starch present the mixture will turn blue or purple or maybe black. If it stays reddish, there isn't enough starch to make it change.

 

[Beestin]

What if you're making a dark stout or something won't the mash water be dark already?

The 2 replies are confusing me. Do I want dark or light when I out the iodine in? Lighter since I don't want starch when I'm done right

 

[RM-MN]

If you only have a drop of dark stout on a white plate the change will be obvious if you still have starch.

 

[Beestin]

Ok thanks. If is cutting a recipe in half do I just use half ingredients with same mash time/temp, etc

 

[November]

You can also buy iodine strips from a homebrew shop. Makes the process a little easier and the little tube of strips will last a long time.

 

[Yooper]

Ok thanks. If is cutting a recipe in half do I just use half ingredients with same mash time/temp, etc

Yes.

 

[Spartan1979]

You can also buy iodine strips from a homebrew shop. Makes the process a little easier and the little tube of strips will last a long time.

How does a strip that tests for iodine in solution tell you if there is still starch in your mash?

 

[Manzier]

You can kind of see it in the mash tun. The liquid goes from cloudy to clear. If you do it for 60 to 90 min your pretty much going to achieve full conversion. I first tied the iodine test but found it a waste of time. A better way then using a plate is to drop some into white chalk (for a blackboard) then drop iodine on it. It'll make the colour obvious.


Sent from my iPhone using Home Brew

 

[Beestin]

Can you mash for too long? Or does it change the flavor the longer you mash?

 

[Yooper]

Can you mash for too long? Or does it change the flavor the longer you mash?

The thought is that longer mash times promote more debranching of the complex malt sugars, so that a super long mash time would give a more fermentable result. (Some easy data about that here: http://braukaiser.com/wiki/index.php?title=Mash_Time_Dependency_of_Wort_Fermentability)

However, some brewers even do an overnight mash and are happy with the final results so it's definitely possible to do a super long mash and have good results, depending on the starting temperature and the grain/water ratio.