Lag time

[oxford brewer]

On sunday i pitched a rehydrated sachet of Danstar Nottingham into my wort(5g)at 2.30pm,when i put the lid on the FV it had a good frothy head and the temp was 23c.I checked the brew at 9.45pm(temp at 22c) and the airlock had no pressure at all(pushed the lid a little to see if the water moved in the airlock and held its position,it did, so it was sealed ok).I checked it again at 7am and expected to see a good rate of bubbling from the airlock but all i saw was a little rise in pressure in the airlock,so i sterilized my mixing spoon took the lid of the FV and gently stirred the sediment at he bottom back into suspension,got home from work at 5.30pm and it is bubbling at the rate of one every 2 seconds.
It just seemed to have a very long lag time compared to using safale-04,which i normally get good airlock activity within 5-7 hours.
Is the Nottingham generally a slow starter,or is the safale-04 just fast?
What lag time do you other brewers experience with your types of yeasts?

Colin

[Scooby]

I have recently used Gervin Ale yeast which some comparison charts say is the same as the Nottingham, I rehydrated as directed just before the end of the boil with luke warm water and 1/2tsp sugar, then added 250ml cooled wort and whisked well to aerate, this was working by the time I had run the rest of the wort through the CFC, I aerate the wort by going like hell with a large ballon whisk when I pitch the yeast. There was airlock activity after about 2Hrs.

I think getting the yeast going prior to pitching and good aeration is the key.