Oxygen and lag times

Can adding pure o2 to wort before pitching increase lag times since the yeast has more oxygen to multiply with, before starting on the sugar.

IME, it decreases the lag time.

Not only that, but the Crabtree Effect states that in the presence of a >.05% glucose solution, fermentation will begin immediately.

interesting…must be the cooler fermentation temps since I have started using a basement.

I’ve had some experience with cooler temps and longer lag times but oxygen should speed it up rather than slowing it down. I think they absorb that stuff pretty quickly. What kind of brew is it? What temp did you pitch at and what’s it sitting at now? Most importantly how fresh was the yeast and did you pitch enough for your gravity levels? All of these can affect the lag time.

Well the last two started after about 20 hours. Both were pale ales with 2 row and crystal malt. Temps were in the mid 60s first one writhe an og of 1.075 and I used 1 gallon yeast starter of 1056. The other was an og of 1.059 yeast was wlp002 without a starter.

A 20-hr lag is quite a bit longer than I typically see when oxygenating and pitching at 62F - how much O2 are you using per fermenter and how are you dispensing it?

1 minute of o2 from a tank with a stone.

Also the first ale tasted good. So it’s not a big deal just trying to understand the process a little better.

Any idea what the date on the yeast was? I guess that wouldn’t really matter much if you made a starter though. Maybe a deficiency of nutrients in the wort itself that didn’t provide enough for healthy growth???

Hmmm…sounds like you did everything correctly and this could be chalked up as a fluke fermentation. Yeast is weird sometimes. So long as your sanitizing was solid everything should turn out well.

[quote=“jrodie”]1 minute of o2 from a tank with a stone.[/quote]If you had a lot of foam on the surface you could try slowing down the flow (foam indicates that the O2 is flowing too fast for the wort to absorb it). And for the bigger beer, try adding 50% more O2. I use a 1L/min flowrate and do 60 seconds for anything up to 1.060, 90 seconds up to 1.090, and two minutes for anything bigger.

Yeah a lot of foam. I’ll try slowing down the flow rate next time.

Did you pitch warm yeast into colder wort? That can cause increased lag times.

[quote=“Belpaire”]Did you pitch warm yeast into colder wort? That can cause increased lag times.[/quote]If his yeast was much warmer than his wort, he would have killed the yeast! :wink:

The yeast was in the fridge up until pitching. I meant to let it warm before pitching but forgot.

Not necessary anyway.