I recently made a Belgium Ale, which was slow to start fermenting, but once it got going it finished fine. It cleared in a secondary and was bottled using 5oz of corn sugar for the 5 gallon batch. It's in the cellar which runs from to low to higher 60's depending on the time of day (a previous batch carbonated just fine in those conditions).
After one week I open a test bottle, it has a little gas pop, tasted ok, but was flat. Another week and the bottle popped well, was poured into a glass and got a head consistent to soda, which dissipated rapidly, leaving the beer tasting ok, but pretty flat. It seems that CO2 is being made in the bottle, does it just take longer to go into solution? Does it just need more time to create a head? Thanks for any insight.