The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Enzyme activity in home ground WW.

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Dnsjo1's picture
Dnsjo1

Enzyme activity in home ground WW.

I know amylase is added to flours to help convert starch to sugars for consumption by yeast, and in my case, LAB in my sourdough starter. But with whole wheat berries ground at home and in bakeries, I assume little amylase is naturally present. Two questions:

1) When sugar is added to the mix, is it enough sugar to feed yeast and bacteria, or do yeast/LAB depend heavily on starch breakdown into sugars to feed and multiply.

2) When WW is ground and used, should enzymes be added, and if so, what type and how and when in the baking process? Does adding a little malt flour accomplish the same thing?

Thanks!

Xenophon's picture
Xenophon

(after all, people have historically been harvesting their own grain, brought them to a miller, then prepared dough and had it baked in a communal oven for centuries before anything was known about bread chemistry.  But what's for sure is that malting grains develop the enzymes (proteases, amylases) that will facilitate transformation by the yeast (and hence the LB I presume).

Also recall reading somewhere (but I'm not exactly sure about the context) that freshly ground wheat should be allowed to 'mature' for a certain time before use.  Not sure if the above is the reasoning behind that though.

golgi70's picture
golgi70

The object of good bread is to pull the natural sugars from the grain/flour using slow fermentation techniques and autolyse. To add sugar would be less desirable unless your flavoring the bread ie. honey.  Whole grain wheat should have  plenty of enzymes therefor the need for additional malt is not usually necessary (unless your only using a small amount of whole grain and white flour) and your white flour is lacking.  In that case some diastaic malt could be added.  I can't remember the exact percentage you can use but don't overdo it or it will make your crumb gummy.  Generally speaking the longer your fermentation the more malt you can use.  It's food supply for the yeast over a low and slow fermentation so it won't run out.  

Since whole grains have all the enzymes they should ever need present millers don't add to them.  But with white flours they will add malt to account for the falling number and keep their flour consistent.  

Autolyse and slow fermentation and the use of  pre-ferments will get you where you want to go without any additional sugar and in most cases the need for diastatic malt.  if your using a decent amount of fresh milled grain.  

As to aging of fresh milled grain.  Some say use it right after milling others say to age it.  That is an interesting topic that maybe more of our scientific members could chime in on.  I use fresh milled grain quite regularly with excellent results.  

Hope this helps to some extent.

 

Josh

Dnsjo1's picture
Dnsjo1

My current method is:

Starter - roughly 13% of total flour at 200%H, Bob's Red Mill or KA white

Sponge - 50% of total flour, all liquid and honey (includes starter) 

Add remaining flour and salt, autolyse, knead, knead in butter at finish.

All the flour is fresh milled wheat except the white in the starter. Lately I've been adding granules of lecithin\ascorbic acid\ginger at 1 tablespoon per 6 cups of flour. The results have been excellent, with everyone raving about the soft moist texture of the bread, especially for sandwiches.

it sounds like I don't need to be concerned about enzyme addition for this application. Maybe are there are times where it is helpful, like with buckwheat, spelt, barley, or rye?

Thank you for the comments. Very helpful. And I'll look further into the need for the rest period for fresh milled wheat.

Bob S.'s picture
Bob S.

Yeast feeds exclusively on simple sugars (dextrose and fructose). Lactic acid bacteria feeds on dextrose. It may also metabolize maltose directly or break it down (still unknown). Maltose is created when diastase (alpha amylase and beta amylase) acts upon ruptured starch granules. Wheat flour is low in diastase, so malted barley is added to supply the necessary diastatic action. Malted barley also contains protease, which helps to relax the gluten and improve volume. Diastase can also be found in fresh, raw honey.Adding sugar (sucrose) will give the yeast and lactic acid bacteria something to eat is there is no maltose present. The enzyme invertase (present in yeast) breaks down sucrose into dextrose and fructose.  Although yeast will metabolize dextrose, fructose, or maltose, it has a definite preference for dextrose. Yeast will consume the dextrose first, then adapt to utilize fructose. When the fructose is exhausted, it will turn to maltose (if present).In answer to question #1: Sugar will provide sustenance to the yeast and bacteria.In answer to question #2: Diastatic malt powder will create maltose that the microbes eat.Acetic acid bacteria are also present in flour, and converts the alcohol produced by yeast into acetic acid.The whole "aging of flour subject" was brought up by me: see Overproofed!If you are going to use freshly milled flour, then it should be used immediately. After about a week, the flour will enter its "sweating" period, and will not make acceptable bread. It must then be aged for a total time of about 2 months before it can be used again. It is not my position that freshly milled flour cannot be used to make bread, only that aging the flour improves the bread baking characteristics of wheat flour. When using "green" flour, Pyler suggests increasing the number of punches (folding).Bob 

Xenophon's picture
Xenophon

I read about the ageing of flour in Suas' 'Advanced bread and pastry' but unsurprisingly it corresponds with what you describe.  Took a look at the 'over proofed' thread.  Very nicely done, I like some objectivity and well conceived experiments, they'll help cut through some of the 'mix the sourdough outside at 11 pm at full moon' lore.  Thank you!

Bob S.'s picture
Bob S.

I just picked up a copy of Michel Suas' book "Advanced Bread and Pastry" at the library today. I will be reading it for a while. Thanks for the mentioning it.

Bob

BeerPaul's picture
BeerPaul

Some great information from Bob S.  I only wanted to add that the amylase enzymes are a product of the malting process.  So in un-malted grains of any sort there wouldn't be a useable amount.

30 Chickens's picture
30 Chickens

You said, "After about a week, the flour will enter its "sweating" period, and will not make acceptable bread. It must then be aged for a total time of about 2 months before it can be used again." Do you know if this is applicable if the freshly milled flour is placed in the freezer right after milling?


Thanks so much, 

Pearl 

Bob S.'s picture
Bob S.

I don't have a definitive answer for you, but I suspect that freezing the flour might halt the oxidative and biochemical changes that are initiated by milling. An air-tight container should definitely be used when freezing flour.

Bob

Dnsjo1's picture
Dnsjo1

Interesting study here:

http://kkopfler.files.wordpress.com/2012/10/effect-of-aging-wheat-flour-on-baked-product.pdf

Definitely worth reading. Their major conclusion: 

"Bread made from flour aged for 0, 3, or 10 weeks showed no significant difference in texture, flavor, or preference. There was a significant difference in color between the 3 and 10 week variations, possibly the result of sampling error. Given that there is no significant difference in the sensory evaluation of flavor, texture, or overall preference associated with bread made from whole wheat flour aged 0, 3, or 10 weeks, when practical, bread may be made with whole wheat flour as fresh as possible to minimize nutrient loss."

I'm guessing that everyone's mileage may vary. It's still tempting to try aging flour, but for now, their summary works for me. I'll keep using it warm from the grinder. (:@))

 

Bob S.'s picture
Bob S.

The study is well written and concise, but it covers flatbread only. I would be hesitant to extend their conclusions to other bread types.