Coffee grounds

a) So, I'm trying to get my hugelkultur bed-box off the ground.  You can read about it here.  In order to get it going, I'd like to add coffee grounds from the local coffee shop.  Given that my hugel-bed-box contains mostly non-rotten wood, how much coffee grounds can I add?  Is there such a thing as too much?  

b) I had some old coffee grounds which I'd picked up last fall, but never used.  They spent a long cold winter freezing in an unheated shed.  I added some water to those, broke up the bigger clumps, and poured this onto my hugel-thing.  Did these seven-month-old coffee grounds still contain nitrogen, or did it disintegrate somehow?  Should I be adding fresh coffee grounds where I spread the old ones?

c) I'd like to add coffee grounds to my compost as well.  Again, is there such a thing as too much?  

I collected about 500lb of used coffee grounds last year and always mix it with some form of carbon. I learned the year before that coffee grounds if left on their own, tend to clod together and form either a brick, or a goopy blob (similar to green grass clippings if they are not mixed).

They tend not to break down well at all on their own if they are in a pile. Now, if you mix them with sawdust  then they become awesome. I have a tower, 6 ft wide by 4 to 5 ft high that is full of used coffee grounds mixed with sawdust. I'm going to grow zucchini in it while I wait for it to break down.

I did a small test last year, and 12 months on, it is about 1/3 decomposed. But I am trying to make compost, not a hugelbed.

I collected about 500lb of used coffee grounds last year and always mix it with some form of carbon.

So, if I mix coffee grounds with leaves, I can put a whole lot of grounds into my compost?  Or should I be following some sort of proportions?

I have a tower, 6 ft wide by 4 to 5 ft high that is full of used coffee grounds mixed with sawdust.

 

That tower sounds awesome.  Where'd you get so much sawdust?  I've been offered sawdust once before, but as most people use at least some mdf and plywood, I wouldn't want to put that in my compost and contaminate it.