safale s33

I used safale S33 for the first time on an old ale recipe from Dave Line. As Experienced by others, the fermentation was vigorous for the first 24 hours, then nothing. Gave the brew a good stir but still nothing. The OG was 6.4 with FG of 2.2. After 5 days with no further action I gave up and I racked of to clear with finings before bottling.

After a further 7 days I dragged the brew out to bottle and to my surprise the air lock was bubbling away nicely and SG is down to 2.0. The temp of late has been exceptionally high so this is probably the explanation as beer temp is up to 25C and hasnt cleared at all. Still, as this is my first time with this yeast, does anyone have an alternative explanation?

I intend to leave the brew a little longer and observe the unexpected fermentation. Might be an interesting end result.

The gas can be excess co2 being released. When the beer finishes it's protected by a layer of co2 - changes in atmospheric pressure or very slow production might push some more out the airlock. If it's fairly regular though it's a good sign it's still fermenting. Like you say, ramping up temp will increase attenuation towards the end too.
In short - leave it alone until it's stable. And ignore beersmith gravity estimates.

This could be caused by a number of things. I've not used this yeast but it might have a higher demand for oxygen than other strains, is particularly temperature sensitive, or perhaps your wort was low in Zinc etc., and that's resulted in a sluggish ferment. You may find that the beer isn't so good as a result though, clearly the yeast has struggled and that can easily lead to unwanted flavours, even worse, it might not be the s33 that's now doing the fermenting. Fingers crossed it turns out ok for you!

Have you tried it?

Have tried and the flavour is promising, definitely a strong old ale taste. It seems to have body and shows signs of having a good head. I intend to barrel it just in case its too lively in the bottle and keep the temp down to 21 as it conditions. I am hopeful that the end result will be drinkable.

I have used this recipe on many occasions and have not experienced problems with fermentation using higher attenuating yeasts