Did starch really convert or is my gravity made up of starch weight

[Ahhh-smooth]

I have read various post on this site concerning the title question, but have not really seen a definitive answer.

When I calculate pre-boil or brewhouse efficiency it is based on the specific gravity achieved after mash in effect. What if full conversion did not take place? Are the calculation wrong because the gravity may be made up of starch vs. sugar? Iodine tests exists, but I have read in this site that it may not be very accurate.

So question is......does unconverted starch contribute to gravity points?

If so, I may have done the BIAB and thus trying to ferment a bunch of unfermentable starch.

 

[kh54s10]

I have no idea of starch conversion but if you did not make up a really strange recipe, why would you think you have a lot of unfermentables??

 

[JRems]

I'm pretty sure a hydrometer can only measure water soluable matter. I don't think starch is soluable, so I don't think it will affect the readings.

 

[Ahhh-smooth]

I have no idea of starch conversion but if you did not make up a really strange recipe, why would you think you have a lot of unfermentables??

Because there is such an emphasis on full volume mash and I did not do that. So I am concerned my use of a small amount of water may not have allowed full conversion of the starch to sugar

 

[RM-MN]

If you had enough water at the right temperature and kept it at the mash temperature range for the right amount of time, your starches converted. Any unconverted starch would be locked inside the grain particles where they didn't get wet enough to convert, such as you might have if you didn't crush the grains.

 

[Ahhh-smooth]

If you had enough water at the right temperature and kept it at the mash temperature range for the right amount of time, your starches converted. Any unconverted starch would be locked inside the grain particles where they didn't get wet enough to convert, such as you might have if you didn't crush the grains.

Thanks, so this is saying the starch would not show up in the gravity readings...correct?

 

[ArcLight]

If you mash at 158F compared to 150F you will end up with less fermentable wort (i.e. your final gravity will be higher).
I assume you get the same original gravity whether you mash at 150F or 158F, but I've not conducted that test myself.

 

[helibrewer]

Starch as amylose or amylopectin will not show on the hydrometer. However, dissolved polysaccharides will influence your gravity, these are the unfermentable sugars (i.e. maltodextrins).

 

[wilserbrewer]

The grain will convert with very little water, or a very stiff mash. You do not need a full volume mash to get conversion.

The grain only needs to be wet, and at proper temperature. I would imagine it takes very little water to convert, saturating the grain would likely be plenty of water for conversion to take place, assuming no dry areas or dough balls in the mash.