I baked some pretty yeastytasting loaves of whole wheat bread when I first started milling grain at home. I thought I had put in too much yeast, but I followed the instructions or at least I thought I did. Turns out there were a few potential reasons that the loaf could seem yeasty.
After forming the loaf - the rise time will vary upon size of loaf, weather and conditions in the kitchen.
A good rule of thumb really is double in its size.
If the loaf starts to look lumpyor cellulite like on top (especially if it was smooth at first) it may have risen too long....sorry...I dont know what to say if that happens....I usually give up and start another loaf or go cry. I guessyou could punch it down and see if it works again.
DONT forget to factor into the Rise time that your oven has to pre-heat! It can take some ovens up to 15 minutes to pre-heat and by then the loaf may have risen too long and will FALL.
Some say you can add more than called for and others say you can add less. I am of the experiment crowd.
ALWAYS make sure your yeast is good and at least room temperature.
If it doesnt act like yeast (instant or otherwise) by spiking out like the little iron shavings on that bald-guy- drawing-travel-game it may be bad.
It was through trial and errors that lead me to writing Tips 10- 13 which are a medley of this vs. that. I sure hope they are helpful to you and can help you avoid my many beginners pit falls!