Under carbed

My Deez Nuts Brown Ale is under carbed. I let it set another week, no change.

If I pour it quickly, I will get a soapy head for a minute, but it fizzles away quickly and looks like maple syrup and tastes a little flat.

Could I open and put a little sugar in each bottle and re-cap?

How much sugar?

I will experiment on a 6 pack and see how it turns out before doing the entire batch.

 

What did you add initially, and how much, to carbonate? What size batch? What temperature have you had it at?

 

Nuts are in the title but are there any nuts in the beer?
Nuts contain fats/oils that kill the head of the beer.

 

No nuts.

It's a normal 5G batch.

I use the same sugar as I do for everything I ever brewed, about 3/4 cup.

I did 2 weeks at 60F.
2 weeks room temp 74 in secondary.
2 weeks room temp in bottles/sugar.

 

Give your beer at least two more weeks, 70° to 75°F. Chill a beer for three days after two more weeks to see if there is some improvement. Make sure your glass doesn't have soap residue. Soap is a quick head killer.

 

You should have plenty of sugar already in there. Can you try a warmer location?

 

I suppose I could put it in the garage. It's been getting up to about 85 degrees. however last time this happened it never carbed any better. in fact I have never seen an improvement after two weeks