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Diastatic power of flaked barley

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pmkealiher

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Beer wiki says it's 0.0%. Does that mean it has no enzymes to convert?
 

erikpete18

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Yup, flaked barley hasn't been malted, so no enzymes. You'll have to mash it with something with enzymes (malted barley/wheat) to get anything out of it, which also means no steeping (in case you're extract). If you are extract, you can always do a minimash with just a small bit of malt and flaked barley. Check out Deathbrewer's stove top partial system for an easy way to do it.
 

BeerDoctor5

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Technically there will be some beta-amylase present in the soluble fraction (~20% of total beta-amylase) of the starch. Beta-amylase is stored in the developing grain and isn't made during germination (i.e. malting) like alpha-amylase. Also, the insoluble fraction will most likely be released in the mash. However, beta-amylase cannot attack the native starch granule. So, for all intents and purposes flaked barley needs base malt to release maltodextrins for its substrate. Therefore, beta-amylase from the flaked barley will be helping out once the alpha and other enzymes are active during mashing. <end science rant>
 
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pmkealiher

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So a malt with no diastatic power still has b-amylase but needs to be released by enzymes from the base malt?
 

thegerm

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as long as you have at least a few pounds of 2 row in your grist, it will have more than enough enzymes to do the job.
 

BeerDoctor5

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So a malt with no diastatic power still has b-amylase but needs to be released by enzymes from the base malt?
I don't think that unmalted barley has zero DP. Doing a brief literature search I couldn't find any empirical evidence. However, diastatic power is correlated both positively and strongly with beta-amylase. Essentially DP is measuring beta-amylase but technically it is measuring the reducing power of all the enzymes. Brewing scientist also measure alpha-amylase activity on its own. If the DP measurement was an indicator of alpha-amylase activity then they wouldn't need to do this.

So to sum up. Flaked barley probably has diastatic power because it has all the beta-amylase as malted barley. However, it does NOT have any alpha-amylase among other valuable enzymes (beta-glucanase). This is the main reason you need to have a base malt.

Also, I'm pretty sure that all malt will have DP, since it's been malted. However, unmalted grains (flaked barley/oats) used in mashing require base malt to help break down their starch.

The mash environment with the contribution of the base malts will help release the bound beta-amylase from unmalted barley malt (flaked barley) as well as release any beta-amylase that is still bound in the malt itself.

DISCLAIMER: All that I have written is correct but not necessary for the home brewer. Describing the flaked barley as having zero DP, while not correct, is not really important for the home brewer. I'm sure the reason is to make sure the home brewer uses plenty of base malt to supply the other enzymes required for full starch conversion. It would be more correct to say it has zero alpha-amylase.

Sorry if I've confused or bored you:eek: I work in this area and can ramble:) :mug:
 
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pmkealiher

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I appreciate your rambling, thanks much. I think I have a better understanding now.
 

Hrahn1995

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Im almost a year late but im doing a braggot in about 2 months with Flaked Rye and need to do it boil free. how could i use the rye to impart flavor? if i use some dry amylase would that break it down so its starches/ sugars can be used?
 

thegerm

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maybe if you used the right amount at the appropriate temperature... but at that point why not just use rye malt and avoid the mystery of whether or how much your starches will be converted.

and the grain will come with a bacteria load regardless whether it's flaked or malted.
 

Schol-R-LEA

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So a malt with no diastatic power still has b-amylase but needs to be released by enzymes from the base malt?
Malts have both beta- and alpha-amylase, and other active enzymes generated in the malting process; whether they remain active depends on how it was kilned. Crystal malts and roasted malts are kilned at a high enough temperature for a long enough time that the enzymes get denatured, which means that they really don't have any diastatic power to speak of. Pale malts are kilned at a much lower temperature so that the enzymes are preserved. Pale Ale malt is kilned a little higher than Pilsner malt, but is also more fully modified (or at least that was the case in the past, modern Pilsner malt is often well-modified), hence it is a bit darker but still has a reasonable diastatic power (one of the reasons Maris Otter is so popular is because it has a much higher DP than most pale ale malts, making it effective with large amounts of specialty malts). Vienna malt is kilned at a slightly higher temperature than pale malt, and dry ('toasted'), which is why they lose a significant amount of DP (they still can convert themselves, but not as much adjuncts as pale malts). Munich malt (IIUC) is kilned at about the same temperature as Vienna malt, but 'wet' (steamed or 'stewed', like crystal malt), and for a longer time than Vienna malt, hence it loses still more DP; lighter Munich malts (10 SRM or lower) generally can self-convert, but darker ones often cannot.

I believe what they were saying was that unmalted barley has beta-amylase in it, which is a different matter, really. Flaked barley has beta-amylase, as it hasn't been cooked or kilned in any way, but not alpha-amylase, which is formed during the malting process. Furthermore, malting itself has the effect of converting the long-chain starches to shorter chain starches and sugars, making them more easily converted. Thus, even though the flaked barley has some ability to convert itself, it is not able to fully self-convert to the degree that it can be made into beer without some amount of base malt. In effect, it has no DP to speak of.

Roasted barley, such as is used in stouts, is highly kilned, and needless to say the enzymes are no longer active in it. Generally, you use only a small amount of it anyway, and trying to make a wort with just roasted barley would be ineffective.

This page explains the whole issue quite well, if a bit briefly.

Comments and corrections welcome.
 

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