Where did the oven spring go?

the final proof (rise) in the tin?  What does the crumb look like?

While I'm not familiar with timing using a bread machine, these loaves look over-proofed to my eye, so I'm suspecting that your room temperature was too warm for an hour-long final proof.  You should have gotten more oven-spring if you had started the bake sooner.

For your next bake, you might want to either proof them in a cooler area, or use a bit less yeast, or just get them in to the oven sooner.

Regardless - these ones still look like they came out pretty darned good, and I bet they taste just fine!

at your recipe.

I ran through your recipe and converted everything to weights using a pretty cool online converter that I just discovered.  You can check it out here.  I'm not vouching for the accuracy of the conversions, but just getting some ballpark values I think I might have zeroed in on the problem:

• 1 cup skim milk  =  248g
• 1 cup water  =  236g
• 1 cup AP flour  =  125g
• 2 1/2 cup whole wheat flour  =  300g
• 4 Tbsp sugar  =  50g
• 2 Tbsp oil  =  28g
• 3/4 oat bran  =  37.5g
• 1/4 cup flax seeds  =  42g
• 1/4 cup rolled oats  =  20.84g
• 4 Tbsp gluten  =  31.25g
• 1 tsp salt  =  6g
• 2 tsp dry yeast  =  8g

Add up your flours:

• 1 cup AP flour  =  125g
• 2 1/2 cup whole wheat flour  =  300g
• 4 Tbsp gluten  =  31.25g

for a total of 456.25g

Then add up your liquids:

• 1 cup skim milk  =  248g
• 1 cup water  =  236g

for a total of 484g  --  which is 106% of your flour weight.

And add up all of your add-ins:

• 3/4 oat bran  =  37.5g
• 1/4 cup flax seeds  =  42g
• 1/4 cup rolled oats  =  20.84g

for a total of 100.34g   --  which is 22% of your flour weight.

I have a couple questions for you:  was this a "bread machine" recipe or from some other source?  And if it was from a bread machine cookbook was it recommended as a "dough" recipe, or to be baked in the machine?  Have you ever baked it on the "whole wheat bread" cycle all the way through?

106% is a lot of hydration, but since your recipe is over 70% whole wheat flour quite a bit of that gets sucked up by the whole wheat.  Also, a good rule of thumb for seeds/nuts added in is to stay under the 25% point, and this recipe gets really close to that.  The 22% would most likely be fine, but remember also that this is an enriched dough (milk, oil and sugar) and they can sometimes have a tougher time holding up that extra material.

I think that IceDemeter is on the right track about the timing and temperatures.  But if this recipe was formulated in some test lab to work on the complete bread cycle, it might be really challenging to make it work by using the dough cycle and finishing by hand.  When you say that it rose beautifully to the top of the bucket, it would likely have set when the heating element came on during the bake cycle and given you a nice loaf, but pulling it out and reshaping it probably degassed it significantly.

I went through the exact same thing with my bread machine about 25 years ago.  The first loaf was the obligatory white bread, the second was a heavy multigrain.  The multigrain got so stiff in the machine it bound up the motor and turned it off - baked right on time and smelled wonderful, but it was a brick.  Happened again the second time I tried it.  That's what led me to getting some bread cookbooks and starting down the path of making bread by hand, and the last 25 years have been the greatest adventure!  So don't give up - you'll keep having fun if you stick with it!  This just might be a recipe you have to do all by hand, or all in the machine.

Looking at the nice job that MonkeyDaddy did at converting the recipe to weights, I actually see even less likelihood that the issue is the recipe itself.  While the hydration does LOOK high, the add-ins will soak up a lot of that water (flaxseed typically absorbs 4x its weight; rolled oats typically 2x, and oat bran can be 3x or more) and this should actually be a pretty manageable dough.

Without knowing your room temperature and the elevation at your location, I really can't suggest what kind of timing you should be looking at for final proof.  It may be an issue of over-proofing (which is what the outside of the loaves look like to me), but might also be under-proofing --- could you maybe include a shot of the inside / crumb to help discern?

Did you do a poke test on these?  If so, how slowly did it fill back in, or did it at all?  How did the dough respond to you slashing it?  Did it seem to deflate at all, did it seem really firm and puffy or was it slack (feeling somewhat like a deflating balloon)?

Hopefully a few more details will help us make some better suggestions for you!

do some thinkin'... since it seems like your room temperature is well within the "normal" for recipes, it shouldn't be a big factor in the timing.  That leaves the possible issue as being the dough temperature coming out of the machine, or the amount of fermentation that occurred during the "dough cycle".

I've never used a machine, but I'm guessing that you put the ingredients in, it mixes / kneads, then heats up or holds a constant temperature for first rise (fermentation).  At this point you are pulling the dough out of the machine, dividing it, knocking it back (de-gassing it), and shaping it to put in to the tins. (Yeah, I'm likely stating the obvious, but I'm kinda thinking this through in writing here!)

You stated that the dough cycle you used is 1 hour and 50 minutes, but is that the correct cycle for a whole wheat dough, or for a standard white flour dough?  Whole wheat, particularly with added whole grains like the rolled oats and with the oat bran, has more available food for the yeast, and so will ferment / rise faster than a standard white flour dough.  Does your machine have a different setting for whole wheat?  Is it possible to try a faster timing than this?

Also, it looks to me like there isn't enough dough going in to your tins, so letting them rise to the top of the tin is basically letting them more than double in volume and over-proof.  With that much whole wheat, I would be looking for only about a 50% rise (if the dough is 1-1/2" deep in the pan, with the sloped sides you would be looking for it rising no more than 1/2-2/3"). 

I don't know if your machine would allow it, but I would adjust the recipe for a dough amount better suited for the tin - so, either drop the total quantity and bake only 1 larger loaf or increase the quantity to bake 2 larger loaves.  It is easier for me to work with baker's percentages for this kind of thing, so I would be thinking like this:

Now, for final timing, I'm thinking that I'd start checking the dough with a poke test starting 30 minutes in to the final rise / proof.  If the dough feels really tight and springs back right away, then I'd give it another 10 minutes and repeat.  If it feels tight and airy, and the dent fills in somewhat slowly, then it is time to get it in to the oven.  If it doesn't fill in, then it has over-proofed, and you can either dump it out, reshape it, and then let it re-proof only for 10 minutes or so, or just put it in to the oven right away, knowing that you won't get as much oven-spring.  I would have the oven ready and pre-heated so that you have no delays once you've tested the dough as ready.

What do you think?

Brava, IceDemeter!  Nicely done!