Try rehydrating the yeast for 30-60mins in a cup of sterile water at roughly 25c before starting. Many of the yeast in the pack may have died if it's close to BBE, so best to give it the best chance possible. Or buy a sachet of S-04 or US-05. If you are ever near Leytonstone then I can give you a spare pack of S-04.
I usually pre-start the yeast in body temperature water, with yeast nutrient, anyway before adding it. Got some spare yeast and a good brewing supply shop down the road anyway.
Try rehydrating the yeast for 30-60mins in a cup of sterile water at roughly 25c before starting. Many of the yeast in the pack may have died if it's close to BBE, so best to give it the best chance possible. Or buy a sachet of S-04 or US-05. If you are ever near Leytonstone then I can give you a spare pack of S-04.