Fermentability Of Rice

[Silo Ted]

Amylase, do you mean? Had to look it up, but Wiki says its an enzyme in human saliva, and also a function of the pancreas. What are the usable plant sources of amylase?

 

[dth]

Amylase is present in barley that hasn't been overly kilned. It is destroyed at higher temperatures so only grains like pilsner or ale malt would contain any. Normally, it is used to convert the starches of the seed into sugars for growth, but by mashing grain at the right temperature the process is quickened, thus converting the starch into sugar for fermentation.

As mentioned earlier, koji mould also converts starches into sugars, although at a slower rate than that which would be obtained by mashing. This is due to the difference in temperature between a mash and a sake brew. The enzymes in barley are finished much quicker due to the higher temperature of the mash but as sake is fermented while the koji is converting the starches it has to been done at a much lower temperature.

Differences in temperature can also play a role in mashing due to different enzymes working at different temperatures. Beta amylase works better around the lower end of mashing temperatures, breaking the starches down into more simple, fully fermentable sugars. Alpha amylase is more dominant at higher mashing temperatures, breaking the starches down less and creating dextrins which don't ferment as well, leaving body and more flavour in the brew.

Other enzymes can be utilised at different temperatures during the mashing process for other effects such as breaking down proteins. All in all, mashing can be an incredibly simple process or extremely complicated depending on the different temperature rests you do.


Dan

 

[Screwtop]

That's scary. My earlier post included asking you for the corona recipe and the reasons why, and how it works in with my rice minded thoughts of the last three days but I left the question out of my reply. All the same you posted the recipe. Are you a bloody mindreader screwtop or did I post it somewhere else?

I was first thinking of a very bland malt flavor, non existant really, with some rice and some light touches of POR to create a good beer that I could enjoy as well as pleasing the Tooheys and VB drinking mates and family. Dont know what the Willamette hop is all about but it would be hard for me not to add a 30 minute, flameout or dry hop to a brew I should bite the bullet and try it.

jakub thats good info and sounds like i suspected. Though I think the dodgy asian super booze I talked about was much higher in alc% than sak'e. Is sak'e distilled, i thought it was more of a strong wine.

No mindreader ST :lol: was responding to:

What percentage of adjuncts would you use in such a beer? :icon_cheers:

I made Zwickels Corona using Horizon for bittering in place of Willamette. It's a fav hop for pale lagers, (a tip from a US brewer). If making a clone then hop as per the bittering (very light) in the recipe with no aroma addition. Brewing for you, then use hops as you will! It is very similar but way better than Corona.

Screwy

 

[wynnum1]

Sweet potato has enzyme and is used raw to convert rice

 

[beerbrewer76543]

Interesting...

Here's an abstract of an article on the subject of sweet potatoes: LINKY

Paraphrasing:
Optimum α-Amylase activity occurred at 71.5
Optimum β-Amylase activity occurred at 53 and it was inactivated at 60

edit: some quick research shows most people pre-boil sweet potatoes when adding to beer but the above information would indicate that a step mash at 53* then 71* would be sufficient for the uncooked potato to self convert its own sugars

 

[beerbrewer76543]

Thinking about sweet potato a bit more maybe the following mash schedule would be appropriate for mashing sweet potato with barley malt:

53*C 30min for sweet potato a-amylase conversion
58*C 60min for barley a-amylase conversion
70*C 30min for both b-amylase conversion

Semi based on Palmer's graph as shown below