[uisgue]

I'm thinking about brewing a pale ale kind of brew with 10-15% black rice ("Forbidden Rice"). Do you think the color will carry on into the glass?  It stains every thing it touches a pretty purple when I cook it for dinner. When I tried a red beet beer, all of the color faded in the boil.
 

[tschmidlin]

Black rice is a dark purple color because of the presence of anthocyanins.  Anthocyanins are sometimes used as pH indicators because they change color with pH.  In an acidic solution, anthocyanins turn pink.  They are also subject to degradation by heat.  So my guess is that you won't get the color you want, but try it in a small batch before dropping the coin on scaling it up.

As a side note, the coloring in beets (betanin) is also subject to hear degradation.  If you wanted to color you beer with beet juice I would add it after the boil.  There is also a pH effect, but it should be a bright red at beer pH.

[denny]

I'm thinking about brewing a pale ale kind of brew with 10-15% black rice ("Forbidden Rice"). Do you think the color will carry on into the glass?  It stains every thing it touches a pretty purple when I cook it for dinner. When I tried a red beet beer, all of the color faded in the boil.

The infamous "Beetweizen"!  Brandt and I were discussing it just this past weekend.

[uisgue]

So, maybe if I boiled the rice (with 5% barley, I read somewhere) and mashed separately, how much Pale Malt (Rahr) do you think that I would need to make conversion? And if I added this to the brew pot after the main boil, do you think that there would be enough natural bugs to funk up my brew.  I know there is said to be pedio/lacto occurring on most, if not all, malts.  Maybe I ought to just try for a sour pink.

[tschmidlin]

Pasteurization of milk is > 160F for 15 seconds, so you could add it at the end of the boil and be ok.

I would cook the rice by itself to gelatinize the starch, then I would do a cereal mash with maybe 10% pale malt at whatever temp you want (~150F).  I would sparge it and hold the liquid, then add it at after the boil, before chilling.

If the liquid is not a deep dark color though, you may have a hard time noticing it in the beer.

[uisgue]

Thanks Tom,...but now I'm kinda confused.  I had thought that the cereal mash and the gelatinization were just other names for the cooking of the rice.  If they're two different things, does 10% pale malt have enough diastolic (sp?) power to convert all the starches to sugars?  I would have guessed it would take at least 50% as compared to the dry weight of the rice.      Help???   I like the idea of adding the rice mash runoff at the end of the boil.

[jeffy]

Thanks Tom,...but now I'm kinda confused.  I had thought that the cereal mash and the gelatinization were just other names for the cooking of the rice.  If they're two different things, does 10% pale malt have enough diastolic (sp?) power to convert all the starches to sugars?  I would have guessed it would take at least 50% as compared to the dry weight of the rice.      Help???   I like the idea of adding the rice mash runoff at the end of the boil.

I think that the purpose of doing a small mash with a portion of malt before boiling is so the cereal decoction boil doesn't get totally gummy and sticky.

[tschmidlin]

My concern with the black rice is that the color will denature if it is cooked after mashing.  There may be some protective effect when the grains are normally cooked, since it retains its color.  So I would cook it as normal in order to gelatinize the starch and retain the color, then mash it to convert the starch to sugar and hopefully keep the color.  I don't know what will happen if you do a standard cereal mash, this just seems like a safer route.

[uisgue]

Okay, that seems to be coming together with how I was picturing the process.  I guess my last question still is how much pale ale malt will it take to convert itself plus all the rice starches?

[Jimmy K]

You want to mash separately to avoid the color change due to pH, right? I don't think that will work because the pH of finished beer is even lower than mash pH.

Normally you'd want around 50% malt to convert a non-diastatic adjunct. That's a ballpark estimate though. It would depend on how diastatically strong the malt is.

[reverseapachemaster]

I must be missing something. If the color in black rice is denatured in heat then why doesn't the rice lose its color when you cook it for eating?

[uisgue]

I think that my main concern is the denaturing of the pigments by heat during a full boil after conversion.  I'm hoping that by basically doing two mashes (one with the rice and one all malt) and adding the rice runnings to the full all malt boil just before flame-out.  If the pH changes it from purple to pink it will still be an unusual looking beer.

[uisgue]

I must be missing something. If the color in black rice is denatured in heat then why doesn't the rice lose its color when you cook it for eating?

I don't really understand, but it might be the difference between the unconverted and converted rice starches.(?)

[tschmidlin]

Denaturation of compounds depends on the total environment and not just the pH and temperature.  There will be interactions with other compounds that could be protective, which might be why it does not fully lose its color when cooked (but it does lose some in my experience).

The pH effects will happen in the beer no matter what, so there's not much to do about it.  The temperature effects can be minimized by pasteurizing instead of boiling.  If you do a regular cereal mash then you will end up boiling the wort for an hour as usual, which could be bad.  It might be ok to do a regular cereal mash and add that wort to the main wort at knockout, I don't know.  Since we know it still has color after cooking normally, that is my suggestion.

As for amount, typically it is 15% 2-row barley in a cereal mash, but that is then added to the main mash for full conversion.  You will need to go higher than that for full conversion, or maybe use some 6-row, or maybe add some amylase.  I don't know how much black rice you plan to use, but I would probably mash it 60/40 with 2-row (barley/rice) to get decent conversion.  I would also probably whirl the rice up in a food processor after cooking to break it open a bunch, and then throw some rice hulls in the side mash.

And after tall that there's no guarantee it will work, but on the other hand it might be more work than necessary.  You would have to do a bunch of experiments to figure that out.

[uisgue]

I guess that I'll have to chalk this one up to experience. It will not be pink. A little bit peach perhaps, but not pink.