Lager fermentation lag time?

[Daniel Ashman]

Hi all,

I brewed my first all grain (BIAB) lager on the weekend. It's a Pilser. Used all Bohemian Pilsner malt and Lubelski hops. Came out at 1.046 OG and 27L. A little under what I was aiming for but not too bad.

My issue is I pitched the yeast on Saturday night and now over 36 hours later I am still seeing no signs of fermentation (no activity in the blow off tube). I am starting to get a bit of a yeasty smell when I open my fridge now though. My question is what sort of lag times should I be expecting and should I be worried?

Some further info:

I made a yeast starter using 2 packets of Mangrove Jack's M84 Bohemian dry lager yeast and a bit of yeast nutrient into 2L of 1.045 OG starter wort. I have a stir plate and put this in my fermentation chamber at 20degC. Unfortunately about 8 hours after pitching the yeast into the starter my fridge stopped working so the starter was at room temperature (high 20s) for about 12 hours before I could fix it. I then cold crashed the starter to 2degC after about 26 hours from pitching for 14 hours. I then decanted it down to 500mL the next day. I then left the starter in the fridge at 14degC during brew day.

My main issue was I struggled to get the temp of my Pilsner wort down to pitching temp, even after cooling in an ice bath then putting it in my fridge. Several hours later it was still well above my desired pitching temperature and I was getting worried about having the wort sitting round in the fermenter too long without pitching. I also wanted to go to bed so I pitched the starter at around 20degC (much higher than I wanted). It took about 6 hours over night for the fridge to bring it down to 12degC.

I stirred the wort for quite a while to aerate before pitching so I think I should have got enough oxygen in there.

Could having the yeast starter too warm for a while or pitching cooler yeast into warmer wort have upset the yeast too much and caused some issues? Obviously it wasn't the plan.

Sorry for the noob questions.

[Peter Smith]

You can grow lager yeast starters at higher temps then you would ferment the main brew with no major issues....  I did a 10L starter at 20C recently (they seem to throw a lot of sulphur aroma at this temp....)   . Haven't used that MJ yeast but Wyeast lager yeasts are not that quick to start either, on the plus side you don't need blowoff tubes for lagers....   From memory its taken 48hours plus for the lagers to start chugging,    even then always seems slow compared with ales.   I would not be concerned.

[oliver]

Hey Daniel, did you rehydrate the dry yeast first, or did you sprinkle the yeast straight onto your starter wort? Sounds like you know what you're doing, probably not the easiest time of year to brew a lager, I struggle to get below 19 with my ground water at the moment. 

36 hour lag time for dry lager yeast is nothing to worry about, I get at least 24 hours - 36 hours with liquid lager yeast, usually dry yeasts are a bit slower. If you didn't rehydrate your yeast before pitching I'd expect the lag time to be even longer, give it some more time before you start worrying :)

A true pilsner is probably a bit ambitious for your first all grain as I'm sure you know, if you're really keen on the style and you want to brew another one while the temps are still warm you could brew a 'faux' lager. Using something like US-05 or workhorse, maybe ferment it a little cooler and longer and give it some time to condition. If you're dead keen on lager yeast you'll need to figure out a way to incorporate ice in your cooling process (ice bath, second immersion chiller in an ice bucket, pump recirc. ice water through your chiller, etc). 

[Daniel Ashman]

Hi Oliver,

Thanks for the reply. No I didn't rehydrate the yeast before pitching the packets into the starter. Just sprinkled them into my conical flask. The tutorials I saw didn't mention rehydrating it first but I definitely do that next time.

You are right in saying I was being a bit ambitious to choose a Pilsner as my first all grain brew. I just figured seeing as I have built a BrewPi temperature controlled fermentation chamber I may as well make use of it.

I thought an ice bath would be enough to cool the wort down but clearly not. I filled up literally the whole bath and added about a dozen 2L salter ice bottles into the bath so it was pretty cool. Kept stirring the wort to try and get the best transfer of energy too. It got down to 35degC pretty fast but struggled to get below that. I will be investing in an immersion chiller before my next brew I think and if I do another lager doing what you say and setting it up to run through an ice bucket or something too.

Let hope it kicks off soon to ease my mind.

[oliver]

Yeh so there's a rough rule of thumb that half the yeast will die if you sprinkle it straight onto wort so you effectively pitched one pack. That would in my mind extend the expected lag phase a bit, you should hopefully start to see a bit of krausen by tomorrow. Don't expect as violent a ferment as with ale yeast too, usually for me lagers have a thinner krausen and less bubbles. 
Cool that you've got the BrewPi going :) Good luck with the brew

[Daniel Ashman]

Wow that's not good! I didn't realise that. Next time I'll definitely rehydrate before pitching into the starter.

[Peter Smith]

In winter with 12C tap water its easy to get wort down but in summer you are a bit stuffed, my fridge drops a 46L fermenter about 1.75C per hour,  so I often pitch the next morning after a midnight finish.   I like massive lager starters or a serious repitch from under a beer.  I often rack to corny and brew at same time,  I dont repitch the entire cake but a serious amount...  About to do a Gladfields special , 95% gladdies pils , bit of gladiator and bit of their acid acid malt, add in southern cross and mot and you have a very NZ based pils...  cheap as chips as well as I got the yeast from one of Ryans beers.

Can you start a BrewPi thread and post pictures.... be good to see it

[Daniel Ashman]

Here's a link to my BrewPi build:

http://forum.brewpi.com/discussion/663/dan-s-build

Note that this is on the old BrewPi forum. They started a new forum now:

https://community.brewpi.com

I'm really happy with the build. It turned out that having my stir plate running in the fridge on the same power supply caused the power supply to overheat, hence the fridge shutting down. I will have to address this before my next brew but at least I know what caused it.

Also got one of Malt Mechanics 30L conical fermenters and this will be my first brew using it so excited about that.

[Aarad Russell]

While my gut feel is that it wouldn't get the yeast off to a good start, does anyone know if pitching into a dropping temperature (eg 20C >> 12C in Daniel's case) adversely effects the yeast compared to a stable (or rising) temperature?

[oliver]

Lots of discussions out there on this, with different people advocating both approaches (pitching above or below your ferment temp). 

My quick summary:
Pitching warm: shorter lag phase, need less yeast, danger of excess off-flavours in finished beer (can be offset by cooling the beer to ferment temp quickly enough)
Pitching cold: safer, need slightly more yeast, less diacetyl, slightly longer lag phase

Have a listen to the brew strong episode on lagers: http://thebrewingnetwork.com/shows/525

I've been trying to pitch cold for my lagers (8 deg or below) and have had good results. Make sure you pitch twice as much yeast as you would for ales.

[Daniel Ashman]

Still haven't seen a single bubble from my blow off tube so I popped the lid and there appears to be good krausen:

Seems more likely now that there is a leak somewhere in the lid or blow-off/thermowell assembly. I think it's ok

[Nicholas Jones]

Hey Daniel check the seal groove on the plastic body of the fermenter if you have no joy with your blowoff assembly. We had one which was poorly machined and not picked up by the manufacturer and consequently had sealing issues (it will be very noticeable if this has occurred). If this is the case a contact me for a replacement. Cheers Nick

[Daniel Ashman]

Cheers Nick will do. I didn't noticed anything when I was putting it all together but I'll have a closer look