Using rice to make a starter

[Culbetron]

I've heard the venerable Jamil mention in two separate broadcasts that you can mash rice to make a starter wort as rice produces maltose when mashed. I'm interested in trying it out as I don't have quite enough barley to make the size batch of starter wort I'd like.

From the little I've found I'm thinking of using about 30% rice to 70% barley to give it the sufficient diastatic umpf.

Has anyone tried this out? Any advice?

 

[Mozart]

I've never made a starter, let alone one with rice, though it's an interesting idea.

That said, if you wanted to go with 30% rice and 70% 2-row barley, you should have enough diastatic power, but it'd be right on the edge. Given that this is a starter and assuming you'll be decanting, a 70/30 mix using 6-row instead of 2-row should have plenty of diastatic 'umph'.

 

[NuclearRich]

Just posting to sub. Sounds interesting

 

[Culbetron]

I thought I'd post what I've found and what I'm planning on doing in case anyone else is interested.

So, because rice doesn't have the diastatic power to convert itself it needs to be mashed with something that have enough to share. The diastatic power of American 2-row is about 140°L (degrees lintner). I'm going to be using german Pilsner malt with 110°L. Rice doesn't have any (as far as I know) power. Your mash needs at least 30°L to be able to convert those starches. So to figure the degrees lintner of your mash you multiply your weight of your grain by it's degrees lintner. I'm going to use 0.65kg of pilsner at 110°L. So 0.65kg x 110°L = 71.5°L contribution by my pilsner. Then divide that by the total grain weight of the batch. I'll add 1kg of rice, so 71.5 / 1.65 = 43°L for the batch which is more than enough for conversion.

Rice has a typical yield of 32ppg at 85% mashing efficiency (the exact same as us 2-row pale malt. So I just plugged my recipe into brewersfriend and it tells me that if I can get 9 liters of 1.040 wort with my pilsner and rice.

So I'll give it a shot soon and see how it works.

Got all my info from the following sources:
http://beersmith.com/blog/2010/01/04/diastatic-power-and-mashing-your-beer/
http://www.howtobrew.com/section2/chapter12-4-1.html

 

[Culbetron]

Ok, brewed up some starter wort. Worked out fine. Here's the info and my final recipe:

6.5 Liter batch
550g German Pilsner
600g White rice

Precooked the rice
Mashed at
140f for 15 mins
158f for 60 mins
Sparged at 170f
Boiled 90 min

OG 1.042 at 74% efficiency.