Failed fermentation/duff yeast

[bbslaw]

I put a Brupaks Irish Moor Stout kit on last night. Everything seemed to be fine. Rehydrated the yeast in boiled, cooled water (as instructed), stirred the wort vigourously to introduce oxygen. As of now, nothing has happened. I had a look this morning and there's no activity on the surface of the wort. Airlock hasn't moved at all. I thought it might be a bit chilly, so I wrapped it in a fleece and put it nearer the radiator. Still nothing so far.
I'm concerned the yeast was defective - it was the 6g pack that came with the kit, said XTBB Premium on it. As far as I'm aware it wasn't exposed to extreme temperatures and I rinsed VWP off everything I used very well.
I have the yeast from another kit (St Peter's Ruby Red Ale), which I'm thinking I'll pitch in tonight if there's still no activity, and then replace it when I get the chance to go to the LHBS. Or should I give it longer? I don't want the wort sitting there doing nothing for any length of time. All thoughts welcome

 

[jonnymorris]

Give it at least 24, if not 36hrs before worrying. Also be aware that putting it next to the radiator might warm it up too much.

 

[morethanworts]

Agree, this is a common but understandable early concern. I wouldn't do anything until late tomorrow, nearly 48 hrs on. Some yeasts just have a longer lag period and 24-36hrs is perfectly normal. As long as your vessel is stood at the recommended temperature range, I'd take off any extra wrapping.

One more thing. Ignore the airlock entirely, from start to finish. It may do nothing now, and then still bubble long after fermentation has finished later on, for example, as the beer loses gas. Trust your hydrometer and nothing else, but unless you don't see some krausen by 48 hrs, then don't go sticking even that in until around 8 days or so, to take an initial SG reading.

 

[bbslaw]

Thanks for the advice. Patience paid off (as always). It's got a krausen on top and is smelling beery/yeasty now, so I can relax. Have just never had one that took so long to get going, but it's possibly due to cooler temperatures. Phew!