I made a real stupid mistake. Can I save this batch?

[Sarrsipius]

Brewed 10 gallons of Milk Stout on Sunday. Into the fermenter and pitched yeast starter about 2pm sunday. By bedtime it was actively fermenting. I ferment in a stainless conical inside an upright freezer with temp controller (probe in thermowell sensing wort temp).

I have a small space heater in the freezer so I can maintain temp up or down depending on the garage temp. To start off I had it in heat mode with the heater plugged into the controller (maintaining 66 deg). Monday night at 10pm I checked the beer and it was in a very active fermentation and the temp had gone up to 68 so I plugged in the freezer and set the controller to cool and maintain 67deg.

Problem was, I forgot to unplug the heater. Before leaving for work this morning I checked the temp on the controller and it read 99deg. Holy ****!!! I opened the freezer and imediately saw my mistake (the heater and freezer were both running and the heater was winning the battle). There is no bubbling in the airlock and I suspect I've killed all the yeast only about 24 hours into fermentation. I unplugged the heater and will let the beer chill back to 70deg today.

At lunch today I will go to the HBS and pick up a smack pack of 1056 (same yeast pitched from the starter) and re-pitch that when I get home tonight. Hopefully I can get fermentation started again.

Anyone have any other suggestions? I'm wondering if that yeast threw off a bunch of funky esters as it warmed from 68 to 99 degrees over night. I'm not sure what 1056 does when it gets that hot. I hope I didn't ruin this batch!!!

 

[Snafu]

Odds are you just killed 300 billion cells, but hey, they are pretty robust. chill back down and see what happens. Prolly going to have some funky flavors, name it the Atomic Waste Land and give it to your friends. How long was it at 99 deg?

 

[Homercidal]

AFAIK 99 degrees is not quit enough to kill yeast. I've had a professional brewer recommend near that temp for a saison. In fact, I think I read that you should target around that temp for rehydrating dry yeast.

It's outside of the yeast's optimal range for flavor though. Hopefully they haven't cranked through the sugars and made terrible tasting beer!

 

[Sarrsipius]

It was at 68 at 10 pm and at 99 at 7am.

 

[Sarrsipius]

AFAIK 99 degrees is not quit enough to kill yeast. I've had a professional brewer recommend near that temp for a saison. In fact, I think I read that you should target around that temp for rehydrating dry yeast.

It's outside of the yeast's optimal range for flavor though. Hopefully they haven't cranked through the sugars and made terrible tasting beer!

I hope you're right. There were no visible signs of fermentation this morning so I'm fairly certain fermentation at least stopped. Hopefully between getting the temp back down to normal and pitching another smack pack of 1056 I can get it fermenting again and the new healthy yeast may be able to clean up some of what the first pitching may have thrown off during the high temp.

All told, I'm guessing it will spend about 18 hours outside it's normal temp range.

 

[JeepDiver]

Doubt the yeast are dead but they probably through some seriously nasty off flavors. I'd plan on racking and letting that age in secondary at least a month after primary is done

 

[JeepDiver]

That big of a starter at those temps I'd bet you are close to FG

 

[Seven]

I'd cool it back down to where it should be then take a gravity reading to see where it's at. If fermentation isn't complete and doesn't restart (assuming it stopped because of the high temps) then pitch more yeast.

No use stressing over off flavors, etc., until it's done fermenting and you've had a chance to taste it.

 

[Sarrsipius]

I'd cool it back down to where it should be then take a gravity reading to see where it's at. If fermentation isn't complete and doesn't restart (assuming it stopped because of the high temps) then pitch more yeast.

No use stressing over off flavors, etc., until it's done fermenting and you've had a chance to taste it.

That's the plan. I'm still going to re-pitch though(it won't do any harm and may help provide for more healthy yeast to clean things up).

 

[Sarrsipius]

That big of a starter at those temps I'd bet you are close to FG

maybe. I'll take a gravity reading tonight.

 

[stevea1210]

Hopefully the yeast didn't throw too many off flavors. I wouldn't be surprised if fermentation was already completed.

This won't help you with your current batch, but could help in the future.

I bought a 2 stage controller for my ferm chamber. That way I can set a high and low temp and the controller will turn on either the freezer or the heater automatically. No need to manually make the changes.

Costly upgrade to the single stage you have already, but it could prevent a repeat.
This is the one I got:
http://www.etcsupply.com/ranco-etc211000000-stage-prewired-temperature-controller-p-110.html

 

[beerman0001]

Yeast has to hit around 120 to be killed by heat. I bet they where really happy at 99.

 

[Sarrsipius]

Hopefully the yeast didn't throw too many off flavors. I wouldn't be surprised if fermentation was already completed.

This won't help you with your current batch, but could help in the future.

I bought a 2 stage controller for my ferm chamber. That way I can set a high and low temp and the controller will turn on either the freezer or the heater automatically. No need to manually make the changes.

Costly upgrade to the single stage you have already, but it could prevent a repeat.
This is the one I got:
http://www.etcsupply.com/ranco-etc211000000-stage-prewired-temperature-controller-p-110.html

I had considered the 2 stage but didn't think it was worth the cost. I won't upgrade to it but if I had it to do over again I would probably go with the 2 stage.

 

[Sarrsipius]

Yeast has to hit around 120 to be killed by heat. I bet they where really happy at 99.

Hopefully they were happy enough to not throw off too many esters. If nothing else, this will be a good experiment to find out what this sort of extreme temp range can do to the flavor. If this was going to happen, I wish it had happened on one of my regular recipes. This was the first time with this recipe so I won't know for certain what flavors may have been from the temp issue.

 

[Sarrsipius]

I may have gotten lucky. Gravity reading when I got home from work was 1.028 so most of the primary fermentation may have been complete when the temp went beyond the normal range. The sample tastes fine, no noticeable off flavors or esters. I had the 1056 smack pack I picked up at lunch so I re-pitched anyway and fermentation is restarted (temp back to 68 now).

Does anyone know how to determine how many gravity points I should get from the lactose? It was 2lbs in 10gal.

 

[postal_penguin]

Hopville lists lactose as 35ppg. So about 7 points in a 10 gallon batch(35ppg x 2 lbs / 10 gallons).

 

[Sarrsipius]

Tapped this brew today and it turned out fine. No off flavors, no noticeable:rockin: affects from the temperature excursion! Never give up on a beer!

 

[sweetcell]

Hopville lists lactose as 35ppg. So about 7 points in a 10 gallon batch(35ppg x 2 lbs / 10 gallons).

somewhat off-topic, but lactose isn't fermentable (that's why we use it to sweeten) so it shouldn't add any gravity points.

or so i've been told - am i wrong here?

 

[BrewKnurd]

somewhat off-topic, but lactose isn't fermentable (that's why we use it to sweeten) so it shouldn't add any gravity points.

or so i've been told - am i wrong here?

specific gravity is just a measure of the density of the solution. adding any sugar, fermentable or otherwise, will increase it. It won't add any alcohol, it won't increase the *change* in gravity points from OG to FG, but it will definitely add gravity points to both OG and FG.