joining wood

ijoined 6pieces of 3x1" pine using biscuits and glue,clamped for 24 hours,once finished i took it inside,24 hours later it bent up 1" at one end like a bannana, what do i need to do to stop this next time

Is that 3" x 1"?

Did you make sure you alternated the grain pattern i.e. ununun from the end view. This will reduce the cupping. Also did you glue somewhere damp or outside and the brought into the nice warm indoors, hence drying out the timber very quickly. If you did, next time keep the timber indoors for a day or two first to lessen the moisture content before you glue.

yes it was 3"X1" and i did glue and clamp it in the shed outside and then took it inside the house after 24 hours :now i no what i did wrong,thankyou;