Starch to sugar question?

What happens to a beer where some of the starch in the mash does not turn into sugars before the boil?

Does the yeast try to act on the starch or are you left merely with starchie beer?

Thx.

robertbartsch said:

What happens to a beer where some of the starch in the mash does not turn into sugars before the boil?

Does the yeast try to act on the starch or are you left merely with starchie beer?

Thx.

Click to expand...

Yes, kind of like a monkey having sex with a football.


.....just kidding, I have no idea really but I could guess though.

The yeast won't be able to ferment any starches. So without filtration the beer would probably never clear. There's also a risk (however small) that bacteria or wild yeasts could take hold after packaging, since they can metabolize the starches.

If there's a lot left over it could contribute some body/mouthfeel, but it won't taste "starchy". Think of plain white flour - it doesn't really taste like anything.

Edit: You could use amylase enzyme to break them down, but then you run the risk of drying out the beer more than you intended.

There are residual starches in every beer. Dextrins are soluble starches. No big deal unless there are a bunch of them. Then usually your wort wont be very fermentable and your beer will be very sweet.

Pivovar_Koucky said:

There are residual starches in every beer. Dextrins are soluble starches. No big deal unless there are a bunch of them. Then usually your wort wont be very fermentable and your beer will be very sweet.

Click to expand...

just one correction - dextrins are not necessarily sweet (I believe it depends on which specific types/sizes of dextrins are present,)

JLem said:

just one correction - dextrins are not necessarily sweet (I believe it depends on which specific types/sizes of dextrins are present,)

Click to expand...

Yes, I completely agree. I meant that if your wort wasn't fully converted you could end up with a very sweet beer. which couldn't ferment any farther, not that all dextrins taste sweet. Sorry for the confusion.