Diastatic Power

[Mashy]

I've read a lot of posts on diastatic power and saw a couple formulas as well. Is there a general rule of thumb about what percent of a grain bill should be malted? I know it depends on the malt so this may be a case by case basis.

My recent mash:

19 gal of water
2 tablespoons gysum
26 lbs rye
10lbs malted rye

Got a final SG of 1041 and about 12 gallons out of all that. Rye really sucked up the water. Not sure if this is because rye may have less sugar or I didn't have enough malt. I did through a couple of table spoons of "amalayse enzymes" in towards the end and the mash sweetened up a bit but wasn't overpoweringly sweet. I added sugar to make it worth my time but want to get away from this and do a true all grain. Any suggestions? I was thinking of trying 20 rye and 16 malted next time but wanted some advice/tools from here before. Is there a diastatic calculator like the dilution, SG, etc calculators that I found around here?

[Dnderhead]

its just a average of 30DP or more per LB.
so add up DP of malts,and dived by total LB of grains.
I dont know what it is in metric but must be similar?.
or doing it backword.LB of grains X 30=? and that whould be the DP you need.
dived this by the DP in the malt you are using,this will give you how much
grain you have to replace with malt.

so if you want to use 15lb of grain..and your malt has a DP of 120.
15x30=430 <120=3.75 LB of grain needs to be replaced with malt.(or more)

[rtalbigr]

Like Dnder said, ya want an avg of at least 30 for all grains. With your recipe with 36 lbs ya need 1080 L of DP. If you are using American malted rye you most likely had enough DP, but if it was German than ya didn't have enough.

There isn't really a general rule for per cent, it more of a case by case deal. It really helps if ya know what the DP of your malt is but often you're gonna have to guess. Rahr has the DP printed on the bag labels. Some sites will list their DP.

Big R

[Odin]

In Europe most use not an L-scale, but a WK-scale. What is 30 in the US is like 100 in Europe. A DP of 60L equals 200 WK. Just imagine my hapiness when I was still familiair with the US L-scale and found me some malt with a DP of 289. WOW! Only ... it turned out to be 289 WK, around 95 L ...

Odin.

[Dnderhead]

so in the UK you whould want a WK of 200 per KG?.

[Prairiepiss]

so in the UK you whould want a WK of 200 per KG?.

Ok I mite put my foot in my mouth again. I've been know to do that with metric conversions.

This is how I read it?
Based on 1 lb = .45 kg.

You want a 30 DP per lb correct?
That would be 100 WK per lb?
My math says this converts to.
13.5 DP per KG?
45 WK per KG?

Like I said I mite be wrong. Just trying to learn?

[Odin]

30 L is the minimum. Like 100 WK. So if you have like 80% corn and 20% 6 row of 180 L. The DP is 1/5 of 180 = 36 so enough.

With WK, 200 is enough for 50/50. Say 10 kilo's of corn, 10 kilo's of malt. 289 makes you go to (around) 12 kilo's of corn, 8 kilo's of malt. 8/20 times 289 = slightly above 100.

30L = 100MK = the minimum in any wash. Problem is not conversion, problem is that European malt has less DP. 289 MK (85 L) is pretty much the max here.

Odin.

[Prairiepiss]

Your making my head hurt Odin.

[Dnderhead]

"45 WK per KG?""

no as a kg =2.2 lbs..and if 30 dp = 100 wk so it be a bit over 200wk per KG.
more like ,,,220WK per kg.=30DP/L per LB..

[Prairiepiss]

See I did it backwards again? Ugh I will get this one day? Maybe? Thanks Dnderhead for correcting me yet again.

[Odin]

Ehm ... I think we should leave the kilo's or pounds out of the equasion.

As I understand 100 WK is always 100 WK. For 10 kilo's or 100 kilo's or 1 kilo. Just as with 30 L. Do you have 1 kilo of 30 L and buy 2 kilo's, you still have 2 times 1 kilo of 30 L. That equals 2 times 1 kilo of 100 WK. So that is 60 L or 200 WK in total. Enough to mash another kilo of whatever without DP, whether it be L or WK.

30 L = 100 WK. 60 L = 200 WK. 90 L = ..... 300 WK. Max DP in Europe is 289 WK.

But ... my head spins as well. I have had 3 of my Oats Whiskey allready. Well, actually sugarhead "faux" whiskey. But it does taste good. If you like oats. I didn't, but with every glass I take ... it just gets better!

[rad14701]

But ... my head spins as well. I have had 3 of my Oats Whiskey allready. Well, actually sugarhead "faux" whiskey. But it does taste good. If you like oats. I didn't, but with every glass I take ... it just gets better!

And there's no Diastatic Power calculating required there...

My head hurts too, Prariepiss...

[Prairiepiss]

Ok ok light bulb. I had to read your post 4 times Odin. Before I got why you said leave the pounds and kgs out.

Your going by liters so its volume not weight? For the WK?

[Dnderhead]

I thank I see what Oden saying use a KG of malt to mash a KG of unmalted grain. but when making recipes it dont always work that way.You mite want 30% malt and 70% other grains.as in bourbon you use 51% corn and 1,,,2 or even 3 other grains. that is why they have/use distiller malt with a dp of 200.only 10% of malt in grain bill is needed.
now with brewers malt, base barly malt is 180DP so its not going to work.so one or more of the other grains is going to have to be malted.

[Mashy]

Thanks for the input everyone. At least the first few posts. I tried to follow the liter WK KG LB thread but got so confused I shit myself.

Dnder I cut and pasted your explanation and formula into my distilling word document. Thank you. I'll try again. With that BOP every time I stir it I think it lets the hot water under the false bottom up. It got around 165 a couple minutes AFTER I turned the burner off so I could have denatured some DP power there. Just picked up 50lbs of Briess two row. I'll his 1.050 or better eventually. Until then C&H is my savior.

[Prairiepiss]

Thanks for the input everyone. At least the first few posts. I tried to follow the liter WK KG LB thread but got so confused I shit myself. .

I'm still cleaning the mess I made up myself.

[Dnderhead]

briess has their DP on net.....others mite be there also.
http://www.brewingwithbriess.com/Produc ... _Malts.htm

[Mashy]

Thanks Dndr.

I actually ran across that link in another post by you in a different thread. 140 DP looks pretty good. I ground up 13lbs and will ad 23lbs rye for my batch tomorrow. Hopefully I will hit 1050+ tomorrow.

[Lucky Duck]

Has anyone ever experienced fluctuations in the DP in the grain they are buying from a home brew store, like a batch to batch variation? The reason I ask is that I made my first two trial runs using 6-row barley malt I purchased at the same time from a local home brew shop. Both of those gave me a 1.07 starting gravity using 80% corn meal and 20% 6-row (keep in mind I run very small batch size compared to most of you here). I went back later and purchased some more 6-row (and also some malted wheat). I recently ran a couple of batches using this next purchase of barley malt and got more around 1.05, even though I used the same mashing process as before, or at least as close as I can duplicate using my notes. With the wheat, I thought maybe I had not mashed long enough to solubilize the starch out of the grain and therefore had lower starting starch levels and resulting lower sugar after conversion. But I then ran the exact same grain bill as the first two and still got a lower OG after mashing. I am not thinking of anything I did that much differently (maybe a few minutes difference at each of the steps, I do three), so I'm wondering if DP might vary from batch to batch of malt, and if so, does it vary by enough to really make the difference from 1.07 to 1.05? Just curious if anyone has experience something like this or not?

My other thought on this is that I'm not getting full conversion and plan to get some iodine to check (I haven't been doing that), but I think this is starting to drift off topic and will leave it there on that idea.

[Dnderhead]

even with beer it varies several points.then different malts and different suppliers will very.

[rtalbigr]

There is always going to be that variability. The rule of thump is avg of 30 DP, but to compensate for that variable factor I go with an avg of 40 DP. Rahr is the only malting firm I have come across that labels each bag. With some, like Briess, they post DP on line, but it''s still an avg. So a lot of times its a WAG, and that's the best you can do. It's best to error with some extra DP.

Big R

[Lucky Duck]

Dnderhead, rtalbigr - thanks guys, a learning from my latest couple of runs that I was not expecting. I'll be sure to keep this in mind going forward.

[Washashore]

There is some GREAT information in this thread. A noob like me is forever grateful to all of you masters out there that share so much of your knowledge with us.

Edit: After reading this, I looked back at my original bourbon recipe from this summer and calculated I needed additional 5 lbs. of malt (out of a 49 lb grain bill) for proper conversion. I should start iodine testing as well I suppose.

[res]

Most if not all this information is already covered in this thread but I hope this is a little more of a concise explanation.
Diastatic power is simply the measure of a given malts ability to convert starch into sugar, measured in degrees Lintner. 30 degrees lintner being the minimum a mash can have to convert. Weight of the given malt is not relevant in this equation, e.g. a malt with a DP ( DP = Diastatic power ) of 100 L ( L = degrees lintner ) will always be 100L, if you have a pound a kilogram or a boat load. Weight only enters the equation when you want to mix (dilute) the malt with a adjunct with no DP like corn or unmalted barley etc. For example say your malt was only 30L you could mash it by itself and convert all the starch but you could not add any corn etc, but if your malt was 60L you would have enough DP for the malt and an equal amount by weight of 0 L adjunct, corn etc.
Most mashes however will have a more complex mixture of malt and adjuncts, to denturen the minimum of malt required use this equation:
Total weight of proposed grain ( including you malt ) × 30 ( 30 L being the minimum L needed for conversion ) then divide by the L of your malt, e.g.
For a 5 kg mash with maximum corn using a malt of 180 L: 5kg × 30 = 150 ÷ 180 = .8333 kg of malt required. This equation works for any type of weight measurement because it's simply a measurement of percentages, substitute pounds or whatever so long as you apply all it the way through the equation.

In some countrys WK ( Windisch-kolbach ) is used instead of L as the measurement of diastatic power, this can be easily converted to L using this equation:
3.5 × L - 16 or the to convert L to WK, WK + 16 ÷ 3.5
Hope this helps, and remember 30L is the minimum and it never hurts to go a little higher particularly if your running a less than perfect mashing setup.