Out of interest I saw some 'fresh' yeast going cheap in Morrisons the other day (50p for 4 blocks) I put quotes around fresh coz they were at their use by date. I figured out that if we keep them in the fridge they should be good for abit longer yet :-) Anyhow, Mrs G has baked 2 loaves with them since and they were lovely. Fresh yeast does seem to make a difference.