Lag time increases with oxygenation?

[BlueHouseBrewhaus]

No, this isn't a "is something wrong" thread. It's more of an observation with a question.

SWMBO recently gave me an oxygenation (O2) setup. I have done about 6 brews with it and love it. I used to routinely finish a couple of points above projected FG and am now much more consistent and better attenuated (or at least my beer is). However, I have noticed that my lag time has increased to 36 - 48 hours consistently regardless of the type and strain of yeast. I figured this was because the yeast were now taking longer to "eat up" the oxygen before going anaerobic and producing CO2. I usually ferment in the lower end of the yeast's temp range so I'm used to some lag time but this is significantly longer. I've searched around some and I have also seen posts from people that said their lag time shortened when they started oxygenating.

So what's the story? I do about a minute with a 2 micron stone. Should I do more ... or less? Is the lag time a good thing? Again, I'm liking my results but I'm curious about the process. What have you folks experienced?

 

[WoodlandBrew]

Well, I don't know what the case may be, but I don't think it would be due to aerobic respiration over anaerobic fermentation.

Both Anaerobic fermentation and aerobic respiration produce CO2. See here: http://www.woodlandbrew.com/2013/03/yeast-propogation-with-aerobic.html

Also, the crab tree effect will cause the yeast to metabolize the sugar anerobily even in the presence of oxygen.

I would suspect the lag time to degrease with additional oxygen because it is used by the yeast to convert glycogen to sterol during the lag phase.

 

[schematix]

What temp are you fermenting at and how much are you pitching?

Longest lag I've ever had was about 36-48h with 2 packs of rehydrated US-05 into a 1.060 wort fermenting at 62F. Definitely on the colder side.

Second longest was just less than that with a 1.055 lager using Wyeast 2124 at 51. It was under pitched by about half. That beer was buttery as hell even after a d-rest.

 

[Cyclman]

Are you pitching using a calculator, I do, plus I do O2 injection, and don't ever have lag times that long- typically 12 hours. I end up with great attenuation- I temp control to the low end of the yeast range for 2/3 of fermentation, then let it finish warmer.

As long as the beer's great, I wouldn't worry about lag- I think people obsess with it too much. Overpitching will reduce lag time, but can negatively affect the beer. Good beer's the goal!

 

[BlueHouseBrewhaus]

The batch I did two days ago is a IIPA - OG 1083. Pitched 2 packets of rehydrated MJ West Coast Yeast. Other brews were an ESB (OG 1050 - 1 packet MJ Burton Union), a Vanilla Porter (OG 1049 - 1 liter starter Wyeast 1056), an IPA (OG 1063 - 2 packets US-05), a Brown Ale (OG 1053 - 1.5 liter starter Wyeast 1098) and a Holiday Ale (OG 1068 - 2 packets Notty).

As you can see, a variety of styles and gravities using dry and liquid yeast. I use YeastCalc for my liquid yeast starters with a stir plate. I always rehydrate the dry yeast (although I have pitched dry with good results - but that's another thread). They all fermented in the low 60s and then I bump to high 60s to finish. They all ended spot on for FG. Much better attenuation and consistency than previous brews.

It just seems wierd that they all had this long lag time. As I said above, it's more curiosity than concern. I'm liking the end product. It's just that after 40+ brews, it's like someone flicked a switch. I guess it's the engineer in me. I want to know why.

 

[BlueHouseBrewhaus]

So, right on schedule, the latest brew started chugging and churning 48+ hours after pitching. Temp is at 64F and it's looking just like any other brew. To quote the late, great Mr. Spock, "Fascinating".

 

[beergolf]

That is strange. I have used O2 for a long time and have never noticed a langer lag time. I brew in the morning and usually pitch about 1-2 pm. By the time I get up the next morning the brews are all going strong.

 

[BlueHouseBrewhaus]

Beergolf, that was my previous experience, too. Twelve to 18 hours usually. The only yeast (besides lager yeasts) that typically gave me longer lag times was US-05. As long as the results are still good, I guess I'll just accept it as it is and keep the same process.

 

[beergolf]

It's all about the taste. If your brews taste good that is all that matters. I think too many obsess about lag time. If it works and makes beer who cares if it starts in 4 hours or a couple of days.

 

[ncbrewer]

I'll pass along an email that I got from Danstar: "Our technical manager suggests that you don't go longer than 30 minutes after the start of rehydration before pitching the yeast into wort as the yeast needs nutrients. If there is a delay you could actually add more wort to the rehydration water to give the yeast something to eat while you are waiting to pitch it, so long as it isn't too hot." This doesn't exactly fit your sequence of events, but still might be worth considering. I got improved ferments when I started adding a little cooled wort after the 15 minute initial hydration.

I like to see fairly short lag time because it gives the good yeast a jump start, so that undesirables can't get a foothold.

 

[BlueHouseBrewhaus]

That's a good point about pitching rehydrated yeast. Actually, this most recent brew was pushing that 30 min window for pitching so that may have contributed to this lag, which was even a little over 48 hours. But some of the others were liquid yeasts from starters so it is still perplexing. Well, that current brew now has about 2 inches of krausen and the temp has risen to 66F. It seems happy as a clam. We'll see what happens with the next one.

 

[hendo80]

Since I switched to O2, my fermentations generally start in 4 - 10 hours, and I've been getting super attenuation. I have a .5 micron stone and according to my research, the smaller bubbles oxygenate the wort faster and more thoroughly than with the 2 micron.

I'm sure the 2 micron works, but I also run mine for about a minute and I can guarantee I'm getting a lot more O2 injected with the .5 micron stone.

Try running yours for 2 or 2.5 minutes and see if it helps. Most people use the 2 micron stone with an aquarium pump due to the lower pressure needed to pump air through the stone. The .5 works best with pure O2 tank and regulator setup.

good luck!

 

[BlueHouseBrewhaus]

Hendo, thanks. I did read about the different uses of the .5 vs 2 micron stones. I decided to go with the 2 because it came mounted on a stainless wand, which made it easier to manage, and I heard a lot of complaints about .5 micron stones getting clogged. I figured the 2 micron would still be better than the shake-the-crap-out-of-the-fermenter method. I'll give the next batch another minute or so and see how it does. The strange thing is that my attenuation is right on target. Just a long lag.

 

[DurtyChemist]

If my attenuation was spot on for 6 batches I would stick with what is working and not worry about it. Recently I've been trying a strong yeast and getting a reliable 70-75% attenuation whereas before it was 68 on a reliable day. I'm not going to start looking into using oxygen wands when my site plate and re pitching volumes are getting me where I want to be.

 

[BlueHouseBrewhaus]

I do keep telling myself I should leave well enough alone. But then that damn nagging curiosity rears its ugly head For now, I'll take your advice and do the whole RDW-yada-yada thing.

 

[hendo80]

But do try boosting your oxygen an extra minute...can't really hurt.

 

[BlueHouseBrewhaus]

Just an update if anyone's interested. Just did my latest brew. A Belgian Dark Strong, OG 1086, WLP 530 Abbey, 2L starter. I did 2 minutes of O2. In 8 hours it was chugging away. It's 3.5 gal in a 5 gal carboy and at 24 hrs I just got a blowoff on in the nick of time. Eight inches of krausen!

So it seems the "lag time blues" are over. I actually don't think it was the O2 that made the difference. Probably several factors but I'm not going to worry about it anymore. It's all good beer regardless of how I got there.

 

[hendo80]

Great to hear, and while it may not have been just the O2,'I'll bet it is definitely a positive to the overall equation. Good luck and I'll be curious to hear how your attenuation goes.

 

[brick_haus]

Kind of late, but i inject O2 for 3 minutes, pitch, then 1 more minute. All at 3 psi .5 stone and 10 gallon batches. My lag times are around 12hrs.

 

[Bowtiebrewery]

I actually have seen similar issues with my lag times when adding O2. I See roughly a 36-48hr lag time as well.

OP, I don't think your recent brew is any indication of that changing as I see several variables that you changed. You were using dry yeast before now you used a 2L starter... Unsure if you decanted and then pitched or woke up and pitched at kreusen. Also being a belgian dark strong, thats significantly higher OG than your other brews and its fermentation temp is higher, which would result in a more active and quicker fermentation.

I would say hold the applause for changing your lag time till you brew a common strength ale like a 1.056 APA or something. I bet your lag time will still go back to 48 hours.

 

[day_trippr]

fwiw, I use a half micron stone on an ss wand (Williams, iirc) and give a 5+ gallon batch 4 minutes @ .5 liters per minute while constantly swirling the beer with the wand.

If I pitch at 4pm-ish the beers almost always are actively bubbling along with a healthy krausen by the next morning...

Cheers!

 

[BlueHouseBrewhaus]

Bowtie, actually two of the previous batches were liquid yeast starters pitched at high krausen. Either way, I don't really attribute the current short lag solely to the extra O2. I'm sure it didn't hurt but I'm guessing there are multiple factors I'm not even taking into account. For one thing, the Belgian has a good amount of candy sugar so the yeasties went right to town. And, as you noted, I stated fermentation at 66F instead of my usual 64. I will start raising it into the 70's today. That should really give it a kick.

The bottom line is that the lag time didn't effect attenuation or the final product so I'm learning to let go of my curiosity. I'll probably look back on this 10 brews from now and see that it was just a coincidence that I happened to have several long lags in a row. One thing I think I can attribute to the O2 is that I am much more consistently hitting my FG since I started using it. That makes it worth it for me.

 

[Bobby_M]

I've done a few controlled experiments and I agree that O2 does increase lag time. It's not important though. It's how it finishes.

 

[wobdee]

Could longer lag times be from over oxygenation? I recently read an article in Zymurgy Nov/Dec 2011 by Dan Gordon who stated pure O2 over 12 ppm can kill yeast. He graduated Weihenstephan brewing school so maybe he knows a thing or two. I bet most of us are just pumping pure 02 in our fermenters without really knowing how much is going in there.

 

[beardown2489]

Greg Doss from WYeast said they find 12-15 ppm is optimal in most cases.

 

[day_trippr]

Could longer lag times be from over oxygenation? I recently read an article in Zymurgy Nov/Dec 2011 by Dan Gordon who stated pure O2 over 12 ppm can kill yeast. He graduated Weihenstephan brewing school so maybe he knows a thing or two. I bet most of us are just pumping pure 02 in our fermenters without really knowing how much is going in there.

In the book Yeast , Chris White took a batch to over 40ppm without issue.

He also provided a table showing time vs flow rate to achieve various concentrations, which was very helpful in establishing my own regimen.

I'd trust an actual yeast producer over any brewer...

Cheers!

 

[wobdee]

In the book Yeast , Chris White took a batch to over 40ppm without issue.

He also provided a table showing time vs flow rate to achieve various concentrations, which was very helpful in establishing my own regimen.

I'd trust an actual yeast producer over any brewer...

Cheers!

I agree, I'd trust what Chris White has to say. I guess I need to read his book.Thanks for the info.