Chicory I thought not acorns ? could be wrong however
i think it was just made of anything up to and including sawdust and dirt by the end of the war! 
Quite possibly
Anyways heres some how to make your own Acorn coffee recipes for porta
Boy sprout method
http://www.scouts.org.uk/magazine/OctNov06/p36.html
You will need:
• About 40 acorns • Salt
• Milk and sugar as required • Water
Method:
1. Wash the acorns well and chop them roughly, using a sharp knife.
2. Place on three sheets of foil, on which you have pierced holes, and place over the hot embers for about five minutes, shaking regularly.
3. Remove from the fire and allow to cool before chopping the acorns up into smaller pieces and adding eight cupfuls of boiling water in a foil pan, adding a small pinch of salt to the water.
4. Simmer for three or four minutes and immediately prior to serving, add a small quantity of cold water to make the acorn grounds settle.
5. Serve with milk and sugar as required, and enjoy
Ray Mears method
http://www.howies.co.uk/content.php?xSe ... =x&limit=0
or you could spend the day airsofting feck how long to make a brew
theres nowt so Permanent as temporary
He'd prepare his acorn coffee in advance you nit 
well that or get Mrs Porta to do it for him
thanks for the recipe, and mrs porta wont doing anything to help with "silly airsoft"
the only time she ever mentions airsoft is when she finds a bb in the kitchen garden , or whereever
"i`ll stick these white balls up your arse 
if i see another in my house" , mrs porta to joseph porta , (for the last 4 years )
"Take that you rotton helping of strawberry flan!"
Joseph Porta to "strawberrys and cream", in the sven hassel book ,ogpu prison
My Mrs (being an ex cub leader) reckons acorn coffee tastes the same as the cheap happy shopper chicory stuff. I remember buying some several years ago and it was pretty grim.
"I`ll stick these white balls up your arse if I see another in my house"
I get the same reaction from my Mrs
Its amazing where you find the little blighters, however I've gone from blaming Che for them being found everywhere to erm still blaming Che...well you wouldn't find me leaving BB's all over the house, so it must be HIM 
