Lager Yeast Pitching Temps

[Bloom_198d]

Hello,

I brewed my first lager last night, and had some questions about yeast pitching.

I have read that it is better to pitch slightly colder than the fermentation temp (50F). I have also read that letting the beer start fermenting for 24h before chilling will allow for a good yeast propogation, but will produce more esters and off flavours. My understanding is that warm pitching is worse than cold pitching....but you can still make good beer using the method...yada yada.

Last night by the time the beer was chilled to ~70F it was already midnight so I decided to transfer the beer to a carboy, and aerate the wort with a aquarium pump for 45min while sitting in the fridge (50F). I than pitched the yeast (~600 million cells, starter wort decanted off at 50F) into the warm wort (assuming around 60F) which was sitting in the fridge and slowly cooling.

What will the result from this be? I imagine it would have taken 4-5 hours for the wort to reach 50F, which wouldn't give the yeast much time to produce off flavours. Is the only problem with this method that the yeast gets shocked from all the temperature change? Is it essential to wait 4-5 hours before you pitch the lager yeast?

Adam

 

[BigFloyd]

No need to wait for pitching if you can get it to the target temp quickly. What are you using to chill the wort?

For a lager, I want to try and get it down to 60*F or lower. 45*F is preferable if you can do it.

I would not assume that your wort dropped 10*F (from 70*F to 60*F) in just 45 minutes sitting in a 50*F fridge. Probably more like 2-3 degrees at best at that temperature differential. Air isn't a very efficient conductor of heat. If we have any engineers around, they could tell you exactly how much it cooled before you pitched. I'm guessing it was around 67.5*F

 

[inhousebrew]

If you're confident in your cleaning and sanitizing (which you should be!) I would wait next time and just let it ride in the carboy in the fridge until the morning. At that point it will be cooled all the way and just pitch yeast then. I do this a lot. Especially in the summer when ground water runs warm.

You should be fine though. It will be beer. Just keep a note of this and think about it when trying that first sip to determine whether or not you notice anything.

 

[Bloom_198d]

Haha I am a chemical engineer. Usually I would suspect a pretty significant drop in temp from transferring the wort in the Carboy, prob due to high surface area, agitation and the Carboy acting as a heat sink. Your prob right though and it was somewhere around 65F. Although its prob more realistically a quadratic temperature profile of 60F at the outsides and 68 near the Center. Next beer I will wait the 8h overnight though. I use a wort chiller but it needs to be fixed bc it's flow rate is pretty slow (doesn't hook up to the sink quite right so I just make a siphon.

 

[tgmartin000]

Make sure to do a D-rest and it should be fine.

 

[BigFloyd]

Make sure to do a D-rest and it should be fine.

+1 on the D-rest. I have a maibock that I started cold crashing this afternoon. I took a taste of the hydro reading last week prior to the D-rest and then another taste after the D-rest to compare. Now I know what Diacetyl tastes like - kind of a fake butter flavor with a little bit of sharpness (like from cheap bourbon). After the D-rest, all gone.

 

[Cyclman]

I always recommend a D Rest for lagers 2/3 through ferming.

At that point, yeast were growing, not actively fermenting yet, so there should be minimal to no flavor impact.

I pitch low and let the yeast go up in temp, which they "like" to do. They don't like going down in temp, it can make them sleepy.