The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Diastatic Malt & Overproofing

pardela_de_quartera's picture
pardela_de_quartera

Diastatic Malt & Overproofing

Hello!

In my last two bakes, I've incorporated a very small amount of diastatic malt flour into my mix. I'm mixing a pretty standard country sourdough mix:

KA patent bread flour, 20% freshly milled whole grain, 80% hydration.

I picked up a bit of 6 row malted barley from a local brewery specialty / supply store and processed it using a Mockmill. I was recommended the 6 row over 2 row, as it contains more protein and would provide more enzymic activity. 

I added as little as .002% to my mix (which in the case of 5k of dough, was about 5 grams). 

The dough bulk fermented wonderfully in about 5 hours at 75 deg fahrenheit, and had great strength during shaping. However, after getting pulled from the fridge after 12 hours at 36 deg fahrenheit, it appeared to be very over proofed. My fridge is kept at 36-38 degrees, with about 80% humidity.

I'm curious if the issue is related to the malted barley flour, or the temp/time/humidity of my fridge. Has anyone experienced issues with malt flour like this before? 

Thanks!

DanAyo's picture
DanAyo

Do you happen to know the Diastatic Power (DP)? I’m curious.

But I can’t imagine any strength of malt at such a low percentage causing over fermentation during a cold retard. Are you sure your fridge/retarder is that cool?

The only other thing that comes to mind is a 5 kilo dough. That’s a lot of mass. Although I have no experience with dough that heavy, it is commonly accepted that large amounts of dough retain their temperature much longer than smaller amounts.

What do you think?

Danny

suave's picture
suave

Diastic power of malt does not matter all that much here - whole grain has its own diastatic power, probably on the order of 3-10 °L and that x20% is more than anything malt will provide at 0.002%, so difference between 120 and 160 °L malts is probably neglible.

Bob S.'s picture
Bob S.

If whole wheat berries have been sprouted before milling, they do indeed have a great deal of diastatic power. If the flour is milled from un-sprouted wheat, then the diastatic power is quite low. Rye flour is a different matter, as it is rich in amylases. It all depends on which "whole grain" is under discussion.

DanAyo's picture
DanAyo

It is my understanding the Malted Barley has all been sprouted, BUT the degree of heat used in roasting has a great affect on the DP. And if roasted hot enough (chocolate malt, for example) the flour or grain is no longer diastatic.

I find Brewer’s Malt descriptions difficult to understand. Any information is appreciated.

Danny

idaveindy's picture
idaveindy

Dan,  I sometimes shop at this brewer supply for baking stuff.  I like their descriptions.  If you can't tell what is diastatic or not, they are good at answering questions.

https://shop.greatfermentations.com/category/s/a?keyword=malt+wheat

I've purchased Midnight Wheat (coffee flavor), CaraWheat (caramel flavor), and Chocolate Wheat for making a Postum-like drink.  Just boil the whole grains for about 10 minutes, turn off heat, and then the longer you let it soak, the stronger it gets.  Then pour through a strainer.   2 tsp of grains makes a quart of beverage.  

If anyone misses Postum, this is the way to go. I haven't tried roasted barley in the mix, just this wheat.

No diastatic power in these.  Just flavor and color.  I'll eventually use these to experiment and make water to color and flavor bread.  They have to be boiled first, and then use the water. I tried grinding and throwing in dry into the mix, but they did not dissolve and impart and color; they just hydrated and remained intact bits.

I've used Briess White Wheat and Rahr Red Wheat (both diastatic)  as malt flour in bread.  It seems to work, but I haven't done detailed testing.

idaveindy's picture
idaveindy

1) 5 kilos of dough, at 80% hydration = 2778 grams flour.  5 g malt powder / 2778 g flour = .18 %  (you apparently forgot to multiply by 100 to get "percent.")

2) KA bread flour already has malted barley flour in it. (Look at "Ingredients" under Nutrition Info Box.)  Generally, no need for more diastatic power.

3) Some strains of wild yeast in sourdough ferment very well in the refrigerator, especially if the lactobacillus strains do not produce much strong acid.  My starter is very mild (Carl's Oregon Trail) as in not as  acidic as San Francisco type sourdough.  My current starter keeps on expanding in the fridge a lot faster than my previous San Fran type of starter.

So, all that extra malted barley just made a lot of sugar to feed the yeasties. 

pardela_de_quartera's picture
pardela_de_quartera

ahhh -- yes. I forgot to multiply, you are correct. In any case, .18% ~ .2% of malt flour still feels so little that it shouldn't effect the dough that much. I will give it a-go again without the additional of more malt. Thanks