Pitched right on yeast cake and no sign of fermentation

Hi guys, yesterday I brewed an extract with steeping grains Delirium Tremens clone and wanted to pitch right onto the yeast cake of a Belgian strong golden ale that I bottled at the same time I brewed the DT clone. After reading the thread started by Bob about not pitching right onto the yeast cake mainly because it's always overpitching by a lot and reading some other advice, I poured 1/2 of the cake out before racking the DT clone on top of it. I also added a packet of Safale 04 because I read that the commercial DT uses that in addition to the Belgian yeast. The one thing that all the ferments that are pitched right onto the cake seem to have in common is that they take off immediately and are explosive. I pitched 12 hours ago at 68 degrees and still there are absolutely no signs of any activity. OG of first beer was 1.08 and FG was 1.014 and I used 2 packs of Wyeast 1388 and 1 vial of White Labs 545 with no starter. OG of new wort was 1.086. I poured off at the most 1/2 of the cake but could that have been too much? Should I get some more 1388 and pitch that tonight when I get home from work? Any advice that will help me now is appreciated.

it's generally not recommended to re-use yeast from a bigger beer (>7% I think) as it starts to impact yeast health. half a cake was more than enough yeast since you didn't even need 2 cups worth before the additional S-04. i'd just give it some more time, the yeast are probably worn out from the bgsa

So you don't think I need to pitch another pack of 1388?

no, i think you'll see activity by the end of the day. if it goes another day, i might think about getting more, but there should be plenty in there as is

velorider11 said:

So you don't think I need to pitch another pack of 1388?

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Just to be straight...you have half a healthy yeast cake and a pack of S-04? I think you have plenty of yeast in there for now.

Yes, 1/2 a yeast cake and a pack of 04. I'm bothered because almost without exception, the accounts I've read of pitching onto the cake relate that the fermentations were immediate and extremely vigorous. So I'm wondering why such a long lag time. The prospect of a very short lag time was one of the things that appealed to me so much about this method.

velorider11 said:

. . . . . . . . So I'm wondering why such a long lag time. . . . . .

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Could be any number of things, pitching on a yeast cake is no guarantee of imediate fermentation, the new wort is different for one thing. There are numerous other factors that affect fermentation, some of which are completely out of our control.

wilserbrewer said:

Just to be straight...you have half a healthy yeast cake and a pack of S-04? I think you have plenty of yeast in there for now.

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I wouldn't call half a yeast cake from a high gravity beer "healthy."

Hard to explain, unless you pitched at an unusually low temperature. When I pitch on a cake, that's exactly what I do, shooting for the low end of the yeast' range. Started after loosing about half a batch to a very rapid fermentation.

After a harduous fermentation, the yeasts might be tired and unhealthy and they might need a growth phase anyway, especially with such a high OG on the second beer, hence the lag time. Just wait. It'll start fermenting.