Diastatic power of Mild Ale Malt

[Hopsimus]

Hey Everyone!

I'm looking at doing a Foreign Extra Stout in the next few weeks using the following recipe which I got from BYO mag:

5 Gallon
OG 1.076
FG 1.020
IBU 75
SRM 55
ABV 7.7 %

9 lbs UK mild ale malt
5 lbs Briess Munich malt
0.5 lbs Belgian Special B malt
1 lb Briess Blackprinz malt (500 L)
1 lb Roasted barley (300 L)
20 AAU US Fuggles pellets (90 min) (4 oz at 5% alpha)
Wyeast 1187 (Ringwood ale) or Wyeast 1084 (Irish Ale) or White Labs WLP004 (Irish Ale)

Mash at 152 to 154 F with 20 quarts of water for 90 minutes.
Sparge to collect about 6.5 gallons.
Boil 90 minutes.
Cool to 65 - 70 G and pitch yeast.

My question is, will this have enough diastatic power to convert?

According to beersmith (and web info), Mild Ale malt only has a diastatic power of 53 lintner. Munich only 40 lintner.
So, combined with the other grains, the total lintner in the mash will only be a tad above 40.
From other postings, it is said anything around 35 lintner and under probably won't convert. 40 seems pretty close!

I imagine this is why they say to mash for 90 minutes.

I suppose I could sub in some UK pale malt, like a pound of Maris Otter or Golden Promise, in place of some of the Mild Malt, which would get the total lintner up to 50 or so. Or, outright sub all of the Mile Malt out for MO or GP, but I wasn't sure how that would affect the taste.

Thoughts?

Thanks!

 

[cswis86]

It should have enough to fully convert but a couple pounds of MO or GP definitely couldn't hurt!

 

[VladOfTrub]

Everything will be OK. Saccharification will occur during the rest period. Use iodine for testing for starch. Then, you'll have an idea when everything is good to go.
Test for starch at 20 minutes. When the iodine is placed into the sample and if the iodine turns purple/blue/black in color starch is present. Test every ten minutes when that happens.
If starch is still present after 90 minutes, it's done, Alpha wore out, denatured. Starch carry over occurs.
The other day I was looking at a data sheet for Crisp Marris Otter Malt. Linter, depending on the testing agency was 45 and 50 L. I didn't look at any Marris Otter produced by other malting companies. I'm not sure if Lintner varies in Marris Otter between producers, it may.
Marris Otter is a unique type of malt. It is over modified, low protein malt. The unique part about the malt is the low protein part. Meaning, it has a lot of starch which equals to a bunch of sugar. Usually, high modification and high protein are connected in malt with the exception of Marris Otter.
I just looked at a data sheet for Briess Ashbourne Mild Ale malt Lintner is 65. UK Mild Ale Malt is 40 L. The diastatic power of Weyermann 10L Munich is higher than the diastatic power of Briess Munich 10L. Things vary in malt and in malt houses.

 

[Silver_Is_Money]

I believe that Muntons Marris Otter is at least 100 Lintner. Twice the diastatic power of Crisp.

 

[303Dan]

You'll be fine, it can be used as a base Malt. My Dark Mild recipe is 75% Mild Ale Malt. Though, I will say that the specific Mild Ale Malt I use (Breiss Ashburne) says it has a diastatic power of 65 lintner.

 

[bigplunkett]

Or just get some ensime and add it to the water

 

[Hopsimus]

Cool, thanks everyone.
I believe I'll give it a try as listed.
I'll pick up some iodine and give that a go too.

Cheers!

 

[Hopsimus]

Thought I would post an update (since I hate it when people don't follow up on their posts).

Went ahead and brewed up the recipe as originally listed last weekend.
Mashed for 90 minutes.
Did iodine test, came out 'amber', which means no starch detected.
Tasted nice and sweet.
Gravity came out at 1.080, so slightly higher than predicted - which is fine by me!

Brew is chugging away as we speak in my fermentation chamber.

I'll post the results in a few weeks!

Cheers!

 

[Hopsimus]

Final update.

Bottled a couple of weeks ago. Opened a couple last weekend.
Beer came out great!
Ended up 2 points higher than predicted at 1.024, so that works out to around 7.4% abv.

Decent brown head.
Nice hits of coffee and chocolate on nose.
Taste is more chocolate. Some caramel.
Decent bitterness, but it balances well with the residual sweetness.
Pretty thick mouthfeel.
Went for 2.3 volumes of co2, so has some good bubbles to it.

All in all, very happy with the result.

Cheers!