Clarification needed about the malting process

[perfection]

I understand the steps involved in the process of malting - screening, soaking, partial germination, kilning and deculming. It something about the chemistry that i wish to clarify.

May i clarify that what happens in the barley grain endosperm during the malting process is to activate growth of the seedling and to RELEASE the starch trapped in the protein network by breaking the latter down. The amylase present will BEGIN to hydrolyze the starch, but to a lesser extent as kilning will stop this process, lower the moisture content and retain the amylase and released starch. The remaining significant part of hydrolysis (breakdown of amylose and amylopectin into maltose) will be completed at the time of mashing

This makes malting a process that readies the starch in the grain for enzymatic action during mashing

Is the amylase (alpha, beta or both) produced at the time of germination or are they already present in the endosperm? Do any other major changes occur during malting?

I would like my above facts clarified, corrected or changed in terms of my above understanding of facts

Thanks yet again all you experts here

[dick murton]

Send me a PM with your email address and I will send you some basic info on malting.

[UnFermentable]

You have the basic idea, but the maltster is not RELEASING the starch that is packed in the endosperm. The maltster is really DEGRADING the middle lamella and the cell walls in an attempt to make accessing more of the starch possible. The germination and steeping (hydrolysis) will activate enzymes and enzyme synthesis, yes, and some starch conversion is likely to take place, however the maltster is looking to preserve as much starch as possible for the brewer to convert later in the mash (saccharification). They are really just focused on the breakdown of cell wall proteins and the synthesis of enzymes for diastatic power.

The amylases (and many other enzymes) are located in the aleurone layer, not in the endosperm. When the kernel is hydrated, the aleurone layer is "pierced" by the testa(?) and starts to signal enzyme synthesis. The present amylases (and others) will then increase in content based on this synthesis. Kilning can denature the enzymes, so the maltster balances this process for color, flavor, "modification", and diastatic power.

The endosperm starch is never fully "released" during malting and is made available for increased surface area by way of cracking the grain. This allows the starch to be hydrolyzed, and allows contact with the enzymes that have been previously synthesized during malting. Plenty of things are goin on in the malting process, but this should answer your questions.

[perfection]

Send me a PM with your email address and I will send you some basic info on malting.

Tried sending you my email is but it seems like your PM quota has been exceeded

[perfection]

Thanks UnFermentable
That was concise and understandable
Yes, releasing the starch was incorrect - making it more accessible is a better way of putting it !