Delayed fermintation

[sgt_monkey]

I brewed a double IPA last week, it had a SG of 1.088 and I added in the suitable amount of safale 05 yeast. It sat for almost a week with no activity at all then suddenly started to ferment as would have expected within 24 hours of pitching.
Any ideas on why this would happen?

 

[Pie_Man]

I'm not sure I understand your question. How long did it take for the yeast to show signs of visible fermentation? It sounds like you don't have much to worry about.

It's not critical that your yeast is visibly fermenting as soon as they are pitched, or nearly so. Visible fermentation within 24 is fairly standard, sometimes it takes even longer. Lag time can depend on a number of factors like your pitching rate, temperature of the wort at pitching time, oxygentation levels, etc. Also, keep in mind that the yeast go through phases and not all yeast cells are on the same phase at the same time. There's a lag phase, a growth phase, then the fermentation phase begins.

Also, although not required, I like to rehydrate my dry yeast as this is said to "wake up" the yeast and get them active prior to adding them to your beer.

 

[sgt_monkey]

I hydrated my yeast before pitching and was very careful to oxygenate the wort before pitching too. There was very little sign of yeast activity for a week (a few small bubbles) then 1 week later a mass of fermentation with a massive yeast head rising. I have always had vigorous fermentation within 24 hours with my other brews but this is the first time I have ever experienced a delay. It all looks good now I was just wondering if it would have any negative affect on the beer.

 

[Pie_Man]

Thanks for clarifying, I see you updated the original post. Interesting, a 7-8 day lag period before visible fermentation. No, I've never that before. If it were my beer, I'd wait for fermentation to slow down and take a sample to measure the gravity and taste the beer.

I guess it's possible that a wild yeast could be fermenting your beer, but I woundn't worry too much about that at this point.

 

[sgt_monkey]

Thanks for you input pie_man, the fermentation is slowing so I am going to take a gravity reading tomorrow and 2nd rack if at my target FG. I'll report back.