Do you know what cultivar you have? I am looking for some to malt with a diastatic power high enough for self conversion.
I think you may be breaking new ground here.
The variety we've been using is a proprietary variety developed in Thailand for use in Australia that produces large white grains. It's still undergoing crop and analysis tests and not yet commercially available. Queensland University of Technology has done a fairly extensive chemical analysis on the stalk content and the grains but I don't believe there was included in that analysis any enzymatic variables like alpha or beta amylase, etc.
As far as I am aware, no one has tried to malt the grain of this variety of sweet sorghum and written about it so it's pretty much uncharted territory. It's quite different from most any of the USA varieties that we compared it against such as M81E, Keller, Topper, Dale, Italian and a few others, most of which produce small grains with dark, high tannin content. I'm not aware of what flavour impact the amount of tannin will impart but I would think it would be significant.
Also, you may be aware that Anheuser Busch has marketed a relatively successful sorghum grain beer in the USA for a few years called "Redbridge". I've never tried it as we don't have it here in Oz.
http://www.redbridgebeer.com/homePage.aspx
http://www.redbridgebeer.com/about/ingredientsAndBrewing.aspx
I'm guessing that it's made from traditional sorghum grain (red) grain and not sweet sorghum grain.
my colleagues at the Sweet Sorghum Ethanol Association could probably point you to chemistry figures for various USA varieties.
http://www.sseassociation.org/
As an interesting sidenote -- we approached one of the major brewers here in Oz about potential offtake agreements to use our sweet sorghum for an Australian gluten-free commercial beer and the thing they put them off most was that they wouldn't be able to market the product as "beer" in Australia because anything called "beer" must be made primarily from malted grain! So, if you can demonstrate the viability of a sweet sorghum grain-based beer, there is commercial potential in it.
Let's keep this thread going. Love to hear your thoughts.
Cheers,
Rob
BELOW:
Top: AgriFuels sweet sorghum grain head
Bottom: Traditional grain sorghum head