Bottle carbonation.

[Sozzled Sab]

For my sins I normally use a pb as most of my brews are ales which require only low carbonation levels. I do occasionally bottle which is where my problem lies.
After packaging I put either pb or bottles in the fermenting fridge at 20 degrees for a fortnight. Whereas the pb is producing the usual glass of foam After a week the bottles are still lifeless after 2 weeks.
I prime with 70g of sugar solution per 23l in the pb or half a teaspoon of caster sugar per 500ml bottle.
Would it be better to use a sugar solution in the bottles or is this normal?

 

[pilgrimhudd]

I have no idea why yours aren't carbonating.

I boil up 200mls of water and dissolve 50-100gms of granulated sugar (depending on what i'm brewing) into it, I then syringe 5mls per 500ml bottle for my usual 30-35 bottles.

My personal experience and I have no science behind this whatsoever is that Caster sugar doesn't seem to carbonate as well as granulated. Why that would be is a mystery to me.

 

[jof]

My personal experience and I have no science behind this whatsoever is that Caster sugar doesn't seem to carbonate as well as granulated. Why that would be is a mystery to me.

Do you think they put some kind of anti caking agent into caster sugar like they do in icing sugar & that's what's causing the difference?