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-   -   Enzyme (Diastase) activiy for GF Malted Grains (http://www.homebrewtalk.com/f164/enzyme-diastase-activiy-gf-malted-grains-330902/)

Pucelle 05-24-2012 06:56 PM

Enzyme (Diastase) activiy for GF Malted Grains
Hello Everyone,

I've been perusing the forum to see how to make my own malted grain 'flour' at home to replace barley malt powder. I have seen the different grains people have used the the directions on how they malted the grain. What I haven't found is the differences in enzyme activity for them.

Teff, Amaranth, Quinoa, Millet, Buckwheat, Oats, & Sorghum seem to be the ones people have tried. For those of you who have made beers with these grains did you have to add enzmyes or was there enough in the malted grain to cover the conversion?

The reason I would like to know is cause I am trying to make a fermented paste that uses the malted barley to help feed the fermentation process & being gluten free I looking for a substitute. When I have asked in the GF food places, I've been pointed in the direction of GF home brewers due to the malting process involved in making beer.


KevinM 05-24-2012 08:12 PM

What kind of paste are you looking for, and what was the malted barley doing? Was it the only source of sugar, or was it also supplied to convert other grains?

Scientific research has so far put many of the grains pretty low on the enzymatic scale, usually enough to convert themselves, but not so much to convert outside grains. (This is why we're looking at sweet potatoes).

Also, there are certain molds that creates sufficient enzymes to convert gelatinized grains. These are usually used for making sake, soy sauce and miso paste. Something like a 25:100 ratio. So 2.5 pounds of this koji converts 10 pounds of plain rice.

Pucelle 05-25-2012 11:05 PM

It's a Korean Hot Pepper Paste call Gochujang:
2 pounds of barley malt powder
32 cups of water
10 cups of sweet rice flour
1 bottle of rice syrup (1.6 kg)
4 cups (1 pounds) of fermented soybean powder
16 cups (1.6 kg) of hot pepper powder
4 cups of kosher salt

The water and the barley malt powder are mixed together and heated until warmed. The sweet rice power is mixed in and then you let it sit for a couple hours. Then you bring it to a boil for 2 hours over medium heat until it has reduced by about 25%. Then you add the rice syrup and remove from heat. Once it is cool you add the fermented soybean powder, salt, and hot pepper power until well mixed with no lumps. Then it is transferred to the fermentation container with a mesh top to keep out bugs. It is left in a sunny spot 2-3 months closing on wet days & at night.

I'm guessing the malt powder is being used to help fuel the continuing fermentation of the soybean powder.

KevinM 05-26-2012 07:23 AM

I see. In this situation, the barley malt's enzymes are there to convert the sweet/"glutenous"/sticky rice flour into sugar. I find it slightly strange that it's followed up with more rice syrup.
In only slightly more technical terms "warmed" should be around the 150-158 degree F range, where the enzymes are most active in converting gelatinized starch to sugar, and rice starch is said to gelatinize before reaching this temperature (which is good).

The 2 hour boil does two things. Stops the enzymes from trying to do any more, and reduces the amount of water so that you get a thicker syrupy texture. Any unconverted rice starch should just help thicken up the paste.

In essence, rice syrup is just rice starch and enzymes that converted to sugar, was strained out and then boiled down to a sugary syrup.

Both the sugars from the malt, converted rice flour and rice syrup would fuel the fermentation, and I expect that the fermented soybean powder contains some of the desired yeasts. Though to be honest, fermented soybean is a common ingredient and may not actually contain live yeast. The yeast may just be sourced from the air. The soybeans (aka fermented black bean as my mom & grandmothers translated them when they spoke english), are usually created in a similar way to making sake koji. (Or soy sauce or miso, which I've considered making myself and really do need to start up). The soybeans are steamed, innoculated with a special mold, it grows at a temperature specific for breaking down bean proteins, then salted or brined and then dried, hence, no yeast used to ferment. (For sake, after the koji process, its' then added to regular rice, water and yeast is added to make sake).

It's likely that current GF grains will not meet your requirements. In ideal malting conditions, some could, but so far, we're not getting that outside of a lab (or if we are, it's limited in scope, maybe to Bard's beer). We're working on it though.

I expect that your best option would be to use sweet potato, as that a) contains more than enough enzymes to change the rice flour to sugar, and b) has been used in Gochujang before (well... at least according to wiki and I *always* trust wiki, right?). At the very least, a is true according to various studies, and b is likely in that certain varieties of sweet potato have been used in asian cooking for quite a long time. (16th century).

Taste quality is the main question of our using sweet potato in any fermentation project which is what we're doing more home testing with, but since it's been used in Gochujang before, I don't expect to be too great an issue.

KevinM 05-28-2012 02:55 PM

After reading more about Korean jang, (Doenjang), Chinese Chiang/Jiang, Indonesian Tao-tjo and Japanese miso from various sources, I can see they're somewhat similar. In that they take cooked soybeans and innoculate them with a local mold. Since certain molds have a tendency to be regional, the mold can be different.

The book of miso by William Shurtleff and Akiko Aoyagi talks about these as well and in fact references the traditional processes picks up mold from the rice straw and air when the cooked soybean is wrapped in rice straw and hung up. He does mention that some use koji instead. It also says that gochujang is made in a similar fashion. The mezu (molded soybeans) is mixed with the red pepper, salt and water and left to ferment, and that some add mashed rice dumplings in which rice flour is mixed with water to form a dumpling, cooked to gelatinize the starch and mashed in with the mezu/redpepper mixture and left to ferment.

In that aspect, it looks like koji will be a better substitute, and can be found and some asian groceries (though I don't think I've found it in the ones I go to). You can also make your own koji at home, which I found slightly easier than trying to malt gluten free grains, plus as previously mentioned, koji has a strong enzyme presence. Better yet, you can innoculate the soybeans with koji-kin directly too.

Pucelle 05-28-2012 06:50 PM

Wow, thanks for the detailed information that makes a lot of sense.

In terms of using sweet potatoes, they would need to be slow roasted at 150-170 degrees? The only question I have with using sweet potatoes would be after I've mashed them from the roast and added the water, would the enzymes go into the water? Meaning, after I've mashed, then mixed with the water, at let it sit for a period of time (how long?); do I use the complete mixture or just strain and use the liquid?

I'm also going to look into something called malted rice, I think the translation is wrong as it's the "in between stage" of rice and yeast. Which now that I think about it is probably Koji but I'm not sure what it's called in Korean. I'd recently heard of people using miso as the base for quick gochujang so I was begining to wonder about the process of miso and doenjang since they both produce soy sauce as a by-product.

Thank you for all your help, I suspect that the sweet potato, apple, pear, sun-dried peppers, and sweet rice varieties all have to do with the substitution for the barley malt.

KevinM 05-29-2012 02:41 AM

Actually, I'm not sure that you would want to roast the sweet potato. What you want is the enzymes from the malted barley, sweet potato, apple, koji etc, which will in turn slowly convert whatever gelatinized (aka cooked) starchy material is added (steamed soybeans, cooked rice).

"malt rice" is a poor and confusing translation for koji, or specifically molded rice, in asian terms. It usually doesn't mean rice that has undergone a malting/sprouting process. However at other times, malted rice can mean this process. For example, we, in this gluten free forum, have talked about malting rice like we would sorghum or millet. I don't know what the Korean translation is. This is a link to pretty much the only koji-kin supplier in the US and it's not even a sake specific koji. It's a koji used more for soy sauce and miso. http://www.tibbs-vision.com/maltrice/index.html You can buy it from most brewing places, like Northern Brewer. I'd reference http://www.taylor-madeak.org/index.php as one of the more referenced websites about sake and creating koji from koji-kin.

Yeah, from what I read, miso and jang, as well as the others, have the exact same process of creation. The only difference is that of the mold species. And that's due to region (like how sourdough bread picks up it's yeasts/bacteria from the air specific to the region, and why San Francisco sourdough is different than michigan sourdough.)

I was thinking of the same, using miso and mixing in the finely ground chili pepper. Or going a step further and making your own miso and mixing in the finely ground chili pepper.

Pucelle 06-07-2012 12:42 AM

Ah ok, so just letting the raw vegetable/fruit ferment with the other materials. Today, for the first time I found gluten free gochujang and doenjang and noticed that they were made using Aspergillus oryzae growing on varius grains. I looked at other brand ingredients and saw koji seeds listed as an ingredient on those as well and some growing the fungus on wheat or barley.

I found a place out of New England that also sells Koji (they use it for miso) but they are down for the summer. I think I'll try from using miso as a base first and go from there. From there I can probably figure out the ratio needed for sweet potato, pear, and apple before moving on to going from scratch completely.

Thanks for all your help and ideas.

KevinM 06-08-2012 02:30 AM

Yup, those would be the processes I was reading about. The type of mold used for traditional gochujang is a different strain, but since we probably don't have access to that one, Aspergillus oryzae (koji-kin) or koji should work just fine.

Interestingly enough, making your own koji from rice and soybeans is pretty inexpensive and pretty simple to do. The pain is just waiting, but to brewers, it's not unlike waiting for a wine or mead.

You'll have to let us know how the other ingredients miso/gochujang works out. I heard a proposal for a specific fermented foods area in this forum, but I haven't seen it yet.

mpcondo 12-14-2012 03:01 PM

I malt my own millet and have made some pretty good ales with it. I have found that the diastatic activity is strong enough to convert its own starches, but that's about it.

This is of course not a scientific finding, just what I observe from my trials.

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