Enzymes And Starch Together In The Grain

[Zwickel]

Howdy folks,

maybe Ive a very dumb question. Today, while Im driving home from work, I got some thoughts:

Starch and enzymes are contained together in the grain. I guess, they are homogenius spread in it. Why do the enzymes not yet theire job to convert starch into sugar already while the malt get stored?

Do they need water? or temperature? or both of it at the same time?

What about the malt standing outside in the sunlight, easily it may reach the right temperature?
Is it just water whats necessary for the conversion?

If so, how much water is needed at least to start the process? Is a certain humidity already sufficient for that?

Straight to the point: Is it possible, that moisty malt stored at a certain temp already starts to convert starch into sugar?

thank you guys for possible responses.

Cheers :beer:

 

[apd]

Zwickel,

The starches are locked away from the enzymes and need to be hydrated and gelatinised before they can be turned into sugars.

From How To Brew:

The starches in the mash are about 90% soluble at 130 F and reach maximum solubility at 149F. Both malted and unmalted grains have their starch reserves locked in a protein/carbohydrate matrix which prevents the enzymes from being able to physically contact the starches for conversion. Unmalted grain starch is more locked-up than malted. Crushing or rolling the grain helps to hydrate the starches during the mash. Once hydrated, the starches can be gelatinized (made soluble) by heat alone or by a combination of heat and enzyme action. Either way, an enzymatic mash is needed to convert the soluble starches to fermentable sugars.

 

[Screwtop]

Howdy folks,

maybe Ive a very dumb question. Today, while Im driving home from work, I got some thoughts:

Starch and enzymes are contained together in the grain. I guess, they are homogenius spread in it. Why do the enzymes not yet theire job to convert starch into sugar already while the malt get stored?

Do they need water? or temperature? or both of it at the same time?

What about the malt standing outside in the sunlight, easily it may reach the right temperature?
Is it just water whats necessary for the conversion?

If so, how much water is needed at least to start the process? Is a certain humidity already sufficient for that?

Straight to the point: Is it possible, that moisty malt stored at a certain temp already starts to convert starch into sugar?

thank you guys for possible responses.

Cheers :beer:

Zwickel, malting is required for some grains to create the enzymes needed during mashing to convert the starch to sugars, and to break down the cell walls in the grain so that the enzymes will be able to get to the starch during mashing. Basically to alter proteins into compounds needed for yeast growth. Also to break down gums in the grain so the sparge can run freely.

During malting the grain is spread out and dampened and turned occasionally under light until the grain germinates, then kilned to stop the germination. Drying or kilning time and temperature depends on the style of malt required, for specific colours and flavours from the dried endosperm which emerged during malting.

But then again some grains contain the necessary enzymes and may be mashed without being malted, such as wheat, so your question stands unanswered. Maybe someone with some food science knowledge or experience can explain.

As a kid I remember if wheat got wet it was stuffed. The farmers used to bury it when they produced too much. After it was dug up only the outer few inches were discarded as the moisture and probably some enzymatic action created a kind of protective crust. At Goondiwindi, a town in the wheat belt of southern Queensland, excess wheat which can't be siloed is still stored in pits in the ground with sheets of corrugated iron as walls and covered with tarpaulins until needed.

 

[Charlie]

The amylase enzymes require the water at the right temperature to to begin converting the starches into sugars. I would say that malted grains stored moist (and warm) will start to convert (once the moisture seeps through the husk) - although I'd be most concerned about fungi and other crap also growing

And there are no grains that contain the enzymes without being malted. Unmalted grains can only be added to a mash in the presence of malted grains with enough diastatic ability to convert not only their starch, but that also found in the malted grains. Otherwise you will end up with uncoverted starches, which will make your beer hazy etc etc ... IIRC, the base malts (ie marris otter, golden promise, (ie base ales) and pilsner malts) are able to convert more starch than they actually contain - not sure of the exact ratio though ...

 

[Ash in Perth]

enzymes dont work when they are dry. for the enzymes to be able to convert polysaccarides to sugar, they need to be in the right orientation/position for the active site to attack the saccharides. water allows the enzymes to freely float around, splitting the bonds between the sugar molecules. water (H2O) is the molecule that the enzymes uses to replace the bonds between the sugars. OH- goes to one side, H+ goes to the other end.

If you want me to be more detailed, let me know

 

[Zwickel]

thank you very much folks for the resonance,

enzymes dont work when they are dry. for the enzymes to be able to convert polysaccarides to sugar, they need to be in the right orientation/position for the active site to attack the saccharides. water allows the enzymes to freely float around, splitting the bonds between the sugar molecules. water (H2O) is the molecule that the enzymes uses to replace the bonds between the sugars. OH- goes to one side, H+ goes to the other end

and

The starches are locked away from the enzymes and need to be hydrated and gelatinised before they can be turned into sugars.

From How To Brew:

The starches in the mash are about 90% soluble at 130 F and reach maximum solubility at 149F. Both malted and unmalted grains have their starch reserves locked in a protein/carbohydrate matrix which prevents the enzymes from being able to physically contact the starches for conversion. Unmalted grain starch is more locked-up than malted. Crushing or rolling the grain helps to hydrate the starches during the mash. Once hydrated, the starches can be gelatinized (made soluble) by heat alone or by a combination of heat and enzyme action. Either way, an enzymatic mash is needed to convert the soluble starches to fermentable sugars.

meets exactly the point what I was looking for.
Compliments to all of you, this site is a deep source of knowledge

Cheers

 

[Ash in Perth]

glad we can help

 

[DJR]

Alpha-amylase requires the presence of calcium ions as well, but i think the major stumbling block is not being dissolved in water and the starches gelatinised.

 

[Ash in Perth]

I didnt know that... Is it a cofactor?

 

[DJR]

Yeah, it uses it in the glycolisis as a cofactor. Doesn't work very well with no Ca+ in the liquor. Beta-amylase doesn't have that problem though.

A quite good article on it :

http://www.murphyandson.co.uk/BrewingArticles/Enzymes.htm

And here's another all about calcium

http://www.murphyandson.co.uk/BrewingArtic...rEverywhere.htm

Biochemist brewers freak out! :chug: