The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Bread with wheat starch for PKU

beckybakes's picture

Bread with wheat starch for PKU

I am using wheat starch to bake, due to a medical diagnosis for my son.  No matter what I do, my bread will not rise in my bread machine.  I get a somewhat decent rise in the first cycle.  after the pucnh down, I do not get another rise.  I am using active dry yeast that I purchased in bulk.  I also proof it and the yeast is good.  I am substituting wheat starch for wheat in recipes.  I am adding oat fiber and a special protein to my flour to mimic the makeup of wheat flour.  My "made up flour" is approximately 70% starch, 15% protein and 15% fiber (which is higher in fiber than usual flour).  Any assistance would be helpful.  I do not have the time to deal with a starter and do not have any interest in it.  I need a bread recipe that can start and stop in one day, or be done in a bread machine.  I basically need help figuring out why my recipe won't work.

Thank you!


Bread Engineer's picture
Bread Engineer

I seriously doubt that your yeast is the culprit, and I would be surprised if your fiber was excessive, (according to wikipedia, whole wheat flour is 12.2% fiber, and more than a few people have added additional bran (wheat or oat) to this with acceptable results. Two possible causes come to my mind.

1) Your bread machine is defective and getting too hot and killing the yeast sometime in the middle of the first rise. My mom wore out one bread machine over the course of 4 or 5 years, replaced it with a new one (same manufacturer, update of the old model), and the new bread machine warmed too much during rising, killing the yeast and making bricks. The dough never got a skin on it or gave other indications of excessive temperature. Have you tried making a loaf by hand or by using the machine only for mixing, then letting it rise in a bowl on the counter?

2) dough breakdown. I don't know about the fussiness of your special protein, but earlier in the summer, when it was getting hot but I hadn't turned on the AC, my kitchen temperatures were running in the 80's, pushing 90, and I had issues with dough breakdown using Peter Reinharts epoxy method. The second rise got started, but the tops of the loaves got pockmarked and wouldn't hold up to the full rise. I suspect I had some undesirable bacteria issues. If your kitchen is warm (or if your bread machine is overheating), this might be the issue.

If you have a similar problem rising outside the bread machine, one workaround while you figure out the issue would be to skip the first rise (or significantly shorten it), put it in pans, and bake it as soon as it rises the first time. The texture is likely to be on the coarse side with this method, but its better than nothing.

I don't know much about PKU other than its seriousness - can you use the flour combinations and other tricks people use for "regular" gluten free baking?

lumos's picture

 I am using active dry yeast that I purchased in bulk. I also proof it and the yeast is good.

Usually, it's recommended to use instant yeast rather than active dry yeast for a breadmachine because of the way instant yeast is processed it can be added directly with flour and other ingredientscan without having to  jump start the fermentation process like active dry yeast (by adding it to warm water and sometimes sugar, first, to proof it).  When you said 'I also proof it,' you meant you mixed your already proofed yeast to other ingredients in the machine?  I've never done that way myself (have always used instant yeast for a breadmachine), so I can't tell you if that's a good way to use active dry yeast instead of instant yeast or not, but if you add active dry yeast directly to the machine, I think it's one of the reasons your bread doesn't rise.  One of my friends has been using active dry yeast (just adding it with other ingredients as you'd do with instant yeast),  wondering why her bread never rises, until recently I told her she should use instant yeast.  


I am substituting wheat starch for wheat in recipes. I am adding oat fiber and a special protein to my flour to mimic the makeup of wheat flour

I'm sorry I'm not very familiar with PUK, so I don't know what the diet requirement for your son is, but is the wheat starch processed (during manufacturing) in some way that it's somewhat different from natural starch in wheat flour?  Yeast uses starch in wheat flour as food, so if it's processed in a way it prevent yeast from doing it, this can be another reason for your problem.

Also, which is I was most interested was, in what way 'a special protein' special?  Protein in wheat consists of several kinds of plant protein, one of them gluten which is very important for bread making. It's the strength of gluten which becomes the structure of bread, so without it, bread cannot expand very much in volume. So if it's treated in a way that it doesn't contain gluten anymore or changed the gluten's behaviour, that may be the biggest culprit. 

Regarding if your breadmachine is broken or not, the easiest way to check it is to bake a loaf with ordinary bread flour and instant dry yeast.

Anyway....I'm not sure what I wrote was any help for me or not (if not, I'm sorry), but I really respect and admire your effort and love in dealing with your beloved son's health issue.  Hope you'll be able to find a good way to solve your breadmaking problem before too long. 

Very best wishes. 



beckybakes's picture

Thank you both for your comments.

I think with your assitance, I figured it out.  I was not putting any gluten in the bread.  My son is restricted on protein, but not allergic.  It seems just 1/4 c of regular flour added to the recipe helped with the structure.

I am using active dry, because I have had no luck with instant yeast.  I add the active dry to the bread machine with warm water and sugar and let sit for 15 mins.  Then add dry ingredients.  Instant yeast produced bricks.

I also had some luck putting a wet wash cloth in the machine during the final rise.  My machine may be getting too hot as suggested.  I am able to bake regular bread in it quite successfully.  Just not low protein bread.

Regular gluten free is still too high in protein.  My "special" protein is whey, since it is lower in components that my son needs.  I am going to look into adding vital wheat gluten, to see if I can add less protein but more gluten to the dough.

Thank you!

lumos's picture

Hope it goes well with vital wheat gluten. Let us know the result, won't you?

Good luck!



Chuck's picture

I was sufficiently intrigued by your question -even without any initial knowledge of PKU diets- that I tried Googling to see what I could find about making low-protein bread. (Gluten is so central to most bread-baking that even the idea of baking your own gluten-free bread isn't all that common, and baking your own low-protein bread is quite a bit less common than that. So your question may not be nearly as simple and straightforward as it seems.)

Although I couldn't find a whole lot, with enough searching it appears there are both prescription and non-prescription sources of ready made bread, some sources of "low-protein flour/mix", and even some claims it is indeed possible and reasonable to make such a thing in a bread machine. However, I ran across several warnings that properly made low-protein bread was "odd" in both texture and flavor, so much so that some people don't even think it's worth the trouble at all and just completely avoid bread.

Not having any experience at all with a PKU diet, I wonder if the "about 15% protein" in your "made up flour" isn't already "too much"?

By pre-dissolving the yeast in water (you can do that with Instant too  ...although it's almost never done) and feeding it some sugar, you're giving the yeast an "extra kick", which somewhat (but not sufficiently obviously) compensates for the lack of structure ingredients in your flour.

I suspect (hopefully my guess is wrong:-) that enough gluten to give the bread the structure you desire will be "too much" protein. Most of the protein in normal white flour (at least in some parts of the world) is gluten, so much so that the measures "protein content" and "gluten content" are often used more-or-less interchangeably with respect to white wheat flour. If you mix VitalWheatGluten with WheatStarch, I fear you're going to wind up with something that's pretty much the same as the regular wheat flour you're trying to avoid.

Unfortunately most of the low-protein baking mixes I found gave no clue as to what their ingredients were (apparently it's a "trade secret"), making it rather hard to "roll your own". It was clear that WheatStarch is generally the main ingredient, so you're on the right track. One source though ( gave a list of ingredients:  Wheat starch, modified potato starch, powdered vegetable shortening (partially hydrogenated soybean oil, corn maltodextrin, modified corn starch, sodium silico aluminate), dextrose, hydroxypropyl methylcellulose, sugar, artificial flavor, monoglycerides, salt. It looks to me like WheatStarch is the main ingredient, and most of the other ingredients are sweeteners and other flavorings. (Notable is the ingredients list does not include VitalWheatGluten.) The only ingredients I can see that would provide some structure (in lieu of gluten) are the "hydroxypropyl methylcellulose" and perhaps also the "powdered vegetable shortening". The methylcellulose turns into a "gel"  ...which is another way besides gluten to make an airy structure. A couple other possible alternatives are "xanthan gum" and "tapioca starch", which are often used in recipes for gluten-free breads (gluten-free breads may be a good avenue to explore for low-protein too).

Whether it's significantly cheaper (and low-enough risk) to "roll your own", or whether you're better off to just buy one of the low-protein mixes, is an interesting question. The ready-made mixes do meet your requirements of being very easy and being bread-machine-ready, and you can be sure they really are sufficiently low-protein  ...but I don't know whether or not the cost is reasonable for you. Let us know what happens. 

clazar123's picture

Thank goodness they screen at birth. I actually knew 2 people-one who's son wasn't diagnosed unitl he was much older and by then the protein had cause extensive brain damage and one person who's kid was screened and found positive at birth. She had special dietary needs and when I knew her at 6 yrs old she was extremely gifted and highly intelligent.

You may have some food stuff,baking mixes and drinks available through your local Children's Hospital dietary department. Call and talk to them and talk to the pediatrician. If you have insurance, you may need a doctor's order for a nutritional consult to be covered. They should also provide extensive nutritional education for you. My friend used to make all her daughter's bread in a bread machine (that was when a bread machine was not widely available and was very expensive). She did obtain special nutritional drinks the child had to drink every day to make sure she got what she needed for good growth. She also got baking mixes and special flours for baking and cooking (noodles and such).

There may also be some support organizations that will offer help and info.

This looks good. It is lifelong and definitely good to have help in how to care for and communicate the child's needs torelatives,friends and to your child.

Good luck and have delicious fun that is healthy for all!

cook4love's picture

Hi Becky,

I stumbled across this string doing a google search.  My 11 year old daughter has PKU.  When she went to kindergarten, I went to culinary school.  Bread was one of the toughest recipes to adapt because gluten typically provides the structure.  I found a combination of wheat starch, tapioca, fiber and xanthan gum worked really well.  I have a recipe on our website that is really delicious, but requires a starter -- something you initially said you were not interested in.  On a plus note, the dough keeps in the fridge up to a week (and the flavor improves as it sits).  This way you can mix it up in the evening and then let shape and let it rise in the morning.  The website is called Cook for Love and the link is  There are no fees.  Hope you enjoy!