• #1 by MarkDouma on 07 Sep 2019
  • Hi Tom and others,

    I've been doing quite a bit of low-carb baking of yeast-risen breads and pizzas in which Vital Wheat Gluten makes up around 45-50% of my total flour weight. Anyway, in some of my experimentation, I came across an interesting phenomenon that I'm wondering if you might be able to shed some light on.

    In my control "dough", I used the following:

    30 g VWG
    pinch Kosher salt
    30 g water

    As soon as all the VWG was hydrated, the result was what one would expect: a rubbery, elastic "dough" that could immediately past the windowpane test.

    In an attempt to help dry out the center of my pizza dough (since VWG is quite thirsty, and hydration rates were 88%) I thought I'd try adding whey protein isolate (it seems to have a drying effect similar to egg whites). The experimental dough was as follows:

    Experimental dough
    20 g VWG
    10 g unflavored whey protein isolate (90% protein content, also contains sunflower lecithin)
    pinch Kosher salt
    30 g water

    The result was not what I was expecting: it didn't even remotely resemble a "dough", but was instead a thick, sludgy soup, almost like a batter. It had none of the structure of the control dough.

    I'm wondering if you could help me understand what's happening here? From previous posts I've learned about glutathione and its presence in milk (and dead yeast), which is one reason you scald the milk to denature that protein before adding the milk to the rest of the ingredients. I also recall the active ingredient in PZ-44 is L-Cysteine, which you've mentioned is similar to glutathione in its effects on gluten. I'm wondering whether the whey protein isolate might be serving as an extremely concentrated source of either glutathione and/or L-Cysteine which, to use your bicycle chain analogy, might be like shattering each chain into several pieces so that they can't properly link up with each other? I dug up my old college chemistry book, and borrowed my brother's organic chemistry text book to help understand this, so don't be afraid to throw technical stuff at me ;).

    I also had a question about the nature of VWG compared to the gluten network that's developed when mixing a normal wheat flour dough. While the formula I've come up with that uses about 45% VWG as part of the flour (and 55% non-wheat ingredients) works, I've found it really difficult to stretch out without snapping back. I know you've mentioned that VWG can be hard to work with since it's already "fully developed" and can result in an overly elastic result. In trying to understand what that means, I came up with the following analogy, which I'm wondering if you think accurately reflects what's happening.

    To keep things simple, we'll imagine we're creating a dough that's mixed to full gluten development (and not worry about biochemical stuff during fermentation). To build on your bicycle chain analogy, I'm imagining a bike shop in which we want to build a lattice work of bike chains where the master links have been removed and the chains linked end to end. The end result would be a lattice network of chains that when "baked" (bear with me) would inflate to fill the volume of the store.

    So, the normal method of using bread flour and water and mixing in a stand mixer is analogous to the following procedure in the bike shop: The bike shop receives a palette of boxes of individually-wrapped bike chains. Each employee can take a box of chains to a different part of the store to work. Granted, this is going to take quite a bit of work, as they have to take each chain out of its package, remove the master link and begin hooking the chains up together. (Analogous to the mixing procedure). But because each chain is nicely wrapped they don't have to worry about chains becoming entangled prematurely. Also, since they're isolated from the other employees, they don't have to worry about getting tangled up with them either. The end result is an "extensible" network that was able to sufficiently encompass the entire volume of the store.

    Now, in contrast to that, is a dough that's trying to use, say, 45% VWG as part of its flour (along with other non-wheat ingredients). This is analogous to the following procedure: Instead of receiving a shipment of individually-wrapped bike chains, the bike shop receives a huge cardboard box that contains bike chains that have already had their master link removed and are stacked on top of each other in nice neat rows. To begin to build the structure, each employee scoops out an armful of bike chains and begins walking away to a different section of the store. However, as they do so, some of the chains begin slipping down to the left and right, and as soon as one end of the chain touches another end, they link up "prematurely". All the other employees suffer the same fate: they aren't able to get halfway to their intended spot before all of their chains have linked up, or become tangled up. Moreover, since each worker didn't get as far away from each other, they even begin getting tangled up with each other. The end result is a lattice network that's only half the size of the one imagined above. It ends up making for a tight, dense crumb.

    Thanks in advance,

  • #2 by TXCraig1 on 07 Sep 2019
  • There may be other things going on too, but whey protein is soluble in water.