RIS Fermentation issues

[Orval62]

Yesterday I brewed a BIAB RIS from the Greg Hughes brew book and hit the starting gravity of 1080. Having transferred it into the FV I added a Wyeast London ale yeast smack pack. It's been 24 hrs and still no activity from the airlock, any suggestions?
As I'm concerned I have placed the FV on a heating tray to see if that will kick start it into action. Never used a smack pack before I tend to rehydrate dry yeast, should I put another yeast into the FV or be patient any advice appreciated.

[McMullan]

Ideally, a decent sized starter is made first, especially for a big beer. What was the production date on the Wyeast pack? What volume of wort did you brew?

[Orval62]

The size of this brew is 21 litres, the yeast was in date but unfortunately packaging is deep in the bin so I can't tell the exact use by date. It is still inactive so off to the LHBS in the morning to get some new yeast, it's been suggested to try Safale S-04 and possibly use two packs to get it going. Fingers crossed as the wort tastes great.

[McMullan]

You could try to aerate (agitate) the wort occasionally over the next day or two, but there is a risk of contamination. Hopefully, it will kick off after some delay. Next time you brew a big beer like this, you could rack the wort onto a fresh yeast 'cake' from a session strength beer. Not perfect, but it'll work.

[Orval62]

Gave it a bit of a stir and it started fermenting so thanks very much for the advice. Fingers crossed it will now ferment out.

[Kev888]

Good stuff. For future reference, liquid yeast benefit more from lots of initial aeration of the wort before pitching. High gravity beers are more of a challenge for yeast too, so generally more yeast are pitched than for normal/low gravity beers.

[Orval62]

Cheers Kev, never used the Wyeast smack packs before and will bear that in mind. I tend to use a dry yeast, rehydrating it before pitching so I see the there is activity. The great thing about this hobby you are always learning and there are great forums like Jim's were there is so much experience and knowledge to help you when you have problems.

[IPA]

Cheers Kev, never used the Wyeast smack packs before and will bear that in mind. I tend to use a dry yeast, rehydrating it before pitching so I see the there is activity. The great thing about this hobby you are always learning and there are great forums like Jim's were there is so much experience and knowledge to help you when you have problems.

Next time try using yeast reference J1 from Brewlab. It comes as a slant and you will need to make a starter but it is very good for high gravity brews.

[Orval62]

Just an update on the RIS, well after the slow start it's still fermenting but has slowed considerably. Took a gravity reading this morning and I have it at 1012, there are no adverse smells and it tastes good, smooth,warming with a hint of chocolate. AVB 8.9%, My only concerns are how long should I leave it, to ferment out or should move it onto secondary?
Your thoughts appreciated.