Have I pitched the yeast too cold?

[motman]

Hi all, please redirect me if this has already been covered but I could t find much with a quick google.

I'm wondering the impact of pitching too cold.. Reason being that I have just started no chilling and on the weekend filled the fermenter, started rehydrating my yeast (k97 kolsch) and realised the wort was at 8c and the yeast at 24... I warmed the wort to 9c with the belt and pitched, setting the belt to warm the fermenter to 15.5, which would have taken overnight to achieve.

This will be a pretty common situation in tas in winter I imagine and I could plan to heat the wort in the fermenter pre pitch but that would leave it prone to infection.

So in wondering if he temp shock would be likely to cause off flavours and yeast health issues?

Thanks for any input.

Cheers,
Tom

 

[Yob]

Greater than 10'c temp difference isn't recommended as thermal shock can be an issue.

I see patience is still being learned here... I'd have brought the cube inside, warmed it up and delayed the pitch... Or attemporated the yeast first and pitched.

Likely it'll be ok but not Great practice for yeast health

 

[GalBrew]

I put the cube in my fermenting fridge and heat/cool it to my desired pitching temp the night before. Easy.

 

[yankinoz]

Don't reuse the yeast.

Let us know how it turns out.

 

[manticle]

I always pitch cool although my starter wort will be the same/similar to my main wort.

For intended fermentation at 15, I'd be looking around 12.5ish for my pitch.

If you are no chilling in a sealed cube, you can get your wort to whatever temp you want before pitching with no fear of infection.

 

[mstrelan]

This will be a pretty common situation in tas in winter I imagine and I could plan to heat the wort in the fermenter pre pitch but that would leave it prone to infection.

Couldn't you heat it in the cube?

 

[motman]

Yep, thanks all. I'll heat the cube up next time. Poor forward planning and Sunday arvo rush whilst juggling kids are my key excuses. No fermenter action at this stage, so I may have shocked the poor wee yeasties. Close to identical to the other half (not cubed) of the double batch, so it should make for an interesting comparison. I'll update in a month

 

[dr K]

OP
K-97 ..you mentioned it was a Kolsch yeast?
Certain about that?
Was it factory packed (under inert gas or vac)
Yeast health (including our treatment of it) is critical

 

[motman]

OP
K-97 ..you mentioned it was a Kolsch yeast?
Certain about that?
Was it factory packed (under inert gas or vac)
Yeast health (including our treatment of it) is critical

I believe it is termed 'German ale' yeast by fermentis but Ross at craftbrewer recommended it as a kolsch yeast and quite a few around the traps also. I've had good results for kolsch in the past. I think it is probably the go to in dry yeasts for kolsch.

It was vac packed, repackaged I think from bulk.

Agreed on the yeast health side of things.

 

[Dazzbrew]

Me too.
i brew at night so i put the cube in the ferm fridge in the morning and adjust temp from there (usually still have to knock a few deg off). By evening its ready to pitch at appropriate temp.

 

[klangers]

Something that I've wondered about is:

If one oxygenates with pure O2, waits for say 6 hours until wort has reached pitching temp (eg cooling from 20 deg to 10 deg for a lager), does an appreciable amount of oxygen come out of solution?

Or do you wait until it's reached temp, oxygenate, and then immediately pitch?

 

[GalBrew]

I pitch immediately after oxygenation.

 

[motman]

Something that I've wondered about is:

If one oxygenates with pure O2, waits for say 6 hours until wort has reached pitching temp (eg cooling from 20 deg to 10 deg for a lager), does an appreciable amount of oxygen come out of solution?

Or do you wait until it's reached temp, oxygenate, and then immediately pitch?

I think wort only has capacity naturally for 8ppm or so. I reckon it'd loose the excess above that provided by oxygen quite quickly. It's been a long time since my last chemistry or physics lecture though, so I'm sure someone will supplement these comments with some facts.

 

[Yob]

Nooooo, can only get to 8ppm from natural air, can get well over 12ppm from oxygen which IIRC is bad...

 

[motman]

Nooooo, can only get to 8ppm from natural air, can get well over 12ppm from oxygen which IIRC is bad...

Yep, but if you Leave it to sit after oxygenation it'd loose the o2 back to ambient right? Partial pressures, mumble mumble

 

[motman]

Update, the brew came to life and has a massive krausen. In the end the temp difference would have been about 8c so hopefully not too big a drama