Pitching Temp

[muthead]

Hi All,

Will be putting down a couple of brews over the next 2 days in my new temp controlled fridge, however had some questions around temperature.

1. Does it matter if you pitch the yeast at 20-22deg before you put into ferm fridge set for 18deg or is it better to get the wort down to 18deg and then pitch?

2. Obviously I only have 1 probe on my temp controller - if I measure the temp of 1 fermenter does logic suggest that the 2nd fermenter will be the same temp?

Appreciate some clarity!

Thanks,

Mut

 

[BjornJ]

Hi there Mut,
you should not get any problems from pitching at say 20 or 22, then putting the fermenter in the fridge set at 18.
This will help the yeast in the initial growth phase and the wort will be down to 18 before any real fermentation kicks in anyway.

Here is an article talking about doing exactly this when brewing lagers, to give the yeast a little extra help:
http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers (warm pitching)

So there should be no ill effects from doing this with an ale and that small temp difference.


Having two fermenters in the fridge with only one temp mate works, I have done this several times.
It will not be as accurate as with one fermenter just because when fermenter1 increases wort temperature through fermentation, the temp mate senses this and lowers the fridge temp.
Unless the second fermenter is following the same temperature rise there may be a slight difference of a degree or two.

In reality, pitching two ales using yeast that have similar fermentation temp profiles, it will be ok.
This is what I have done many times, pitch say half with an US and half with an UK ale yeast to taste the difference in the same wort.
I'll set the fridge at 18 or 19 and both yeasts are ok in this range even if one of them were to drop or increase a degree or two more than the other.


That's what I have done, anyway. And not noticed any worse beer than normal


thanks
Bjorn

 

[Wolfy]

Will be putting down a couple of brews over the next 2 days in my new temp controlled fridge, however had some questions around temperature.

1. Does it matter if you pitch the yeast at 20-22deg before you put into ferm fridge set for 18deg or is it better to get the wort down to 18deg and then pitch?

2. Obviously I only have 1 probe on my temp controller - if I measure the temp of 1 fermenter does logic suggest that the 2nd fermenter will be the same temp?

At the start of the fermentation process, when the yeast is reproducing, is when most of the yeast derived flavours and esters are produced. By starting warmer than your fermentation temp the yeast's metabolism will be higher and so more of those flavours will be produced. That may or may not be what you desire, and it may or may not be noticeable in your resultant beer, or only noticeable if you compared to beers that were otherwise identical, and it's only a few degrees higher so the difference could be minimal, the small change should not produce a 'bad' beer, but it will probably impart more yeast-flavours.

To help minimize yeast derived flavours (if that is what you are aiming for) start the fermentation cool (cooler than your fermentation temperature) so the yeasts metabolism is slower and they produce less flavours/compounds/esters when they are most active and reproducing, slowly raise the temp to your fermentation temperature for the bulk of the fermentation period and then raise the temp slightly at the end of fermentation so that the warmer temps help the yeast be more active while they 'clean up' the compounds produced at the start of fermentation.

Air is not a good thermal conductor, so just because 1 fermentor is at the right temperature does not mean the other one will be, an active ferment (which produces heat) could easily mean that the temps are +/- 5 or so degrees in the other fermentor. However most people (myself included) only have 1 temp-controlled probe in the fridge and so we make-do with that situation as best we can. I have a fan in my fridge to help circulate the air as an attempt to keep the inside (and hence the fermentors) at the same temperature as much as possible.

 

[going down a hill]

I stick my temp probe to the side of the fermenter with a bit of insulation so it takes out the fridge ambient temp. If you butt the probe between the two fermenters somehow it could read both fermenters, I suppose.

 

[argon]

if you can fit 2 fermentors side by side, jam the 2 together and stick the probe in between. The probe will take the average and compensate accordingly

 

[muthead]

Thanks everyone, have just put down Neil's Centerillo, sat in the fridge waiting for the temp to get down to 18 before I pitch the yeast.

Unfortunately the fermenters wont fit side by side - they will be one above another. I'll be putting down another tomorrow night so will have to just make the best I can for temp control. The very fact they are in a fridge is progress.....

Cheers,

 

[katzke]

Hi All,



2. Obviously I only have 1 probe on my temp controller - if I measure the temp of 1 fermenter does logic suggest that the 2nd fermenter will be the same temp?

Appreciate some clarity!

Thanks,

Mut

No, fermentation creats heat. If one was more active then the other it could be warmer then the other brew.

If the fridge is 18 you should be OK.

As to pitching warmer? It takes a while to get the last few degrees out of that much wort. The yeast may kick in and start to warm things up before your brew ever gets down to 18C.

 

[Phoney]

If I put two fermenters in my fridge, one sits on the floor of the fridge and the other on a shelf. If the one on the shelf has the probe strapped to it, the one on the floor will be 1 - 2C lower. So when I ferment two simultaneously, I try to keep them 3 - 4 days apart. Put the first one on the shelf at 18C, slowly bring it up to 20C, then put a new batch down on the floor which will be at 18C...

 

[bignath]

I regularly use my fridge to ferment two side by side. Ill admit it could quite easily be different going vertical though...

For what its worth heres my regime:

Because i brew double batches the recipe is identical in both, and given ideal conditions i have grown accustomed to repeatable fermentation results between two batches within reasonable expectations. What i do do though is a couple of days before i plan to ferment, i put both cubes in the fridge to aclimatise. Then i pull them out and get them both started within 10 mins of each other. Active fermentation, end of fermentation, gravity changing profile are as close to identical as i need or want, so i can only assume that any heat produced by each would be also fairly consistent. I only have one probe too, but if the fermentation is (for all intents and purposes 'the same') then any change in the fridge created by the probe on one fermenter, is most likely a welcome addition for the probeless fermenter anyway.

I measure the temp of all my gavity samples of both fermenters just to make sure the probe isnt lying too. I also allow for a slight difference in actual fermenting temp when setting up the controller. If i set it at 17 and the samples are coming out at 18 for example, then thats all i care about.

 

[BjornJ]

just a comment on pitching warmer than fermentation temp;

What he is doing is pitching at 20 or 22 degrees then putting the fermenter in the fridge set at 18.

That means the wort will be chilled before active fermentation begins I would have thought.

Pretty much exactly what this article by Whitelabs Chris White is saying is acceptable for both ales and lagers:
That no flavour compounds are created during the lag phase so this can successfully be done at higher temps (20-22 degrees C.

http://www.whitelabs.com/beer/Yeast_Life_Cycle.pdf




(Chris white is the one who wrote the Yeast book together with Jamil:
http://www.whitelabs.com/education/book.html )

 

[Pennywise]

I've pitched at 26 several times and had no issues. Goes straight in the ferment fridge and 3-4 hors later its down to ferment temp. This is for Ales