Did I kill my yeast??

[brjohns3]

Yesterday, I embarked on my first brewing experience. There were a few hiccups, but nothing major UNTIL...I asked my girlfriend to get the yeast ready as I was sanitizing a the last few things I needed. She brought it to me about fifteen minutes later, and everything seemed fine...except for the fact that the glass felt quite warm. I didn't think anything of it until after I had added it to the wort, topped the carboy off to the 5 gal. mark, and stoppered it with the airlock. A little later I found a link about pitching the yeast too hot so I asked her how hot the water was, and she told me that she turned on the hot water from the sink and let it get pretty hot and then added the yeast. I went back and check how hot that actually is, and the thermometer read 114.5 F. Did we kill the yeast? If so, I have another pack of the same stuff (Safale US-05, dry ale yeast); should I just add it to the wort? It's been about 18 hours, and the airlock hasn't moved. Are there any other visible signs that it is fermenting?

Thanks in advance,
Billy

 

[tonyscha]

I haven't done this myself, but my guess is you killed some of them, but not all of them.

Even with healthy yeast, it can take 48-72 hours to show airlock activity. I would wait it out until 72 hours, if no activity, then add the other packet.

 

[Paradigm]

As the other guy said, likely some yeast were killed. Wait a couple days and if you've seen no activity add some more yeast.

The upside is that at worst case you'll still have beer, just not perfect beer. And, trust me, we've all goofed a few batches.

 

[Bob-MTL]

You did exactly as I did on my first attempt.

After waiting for about a day, we finally got sign of activity. But that activity was not yeast, but some wild bacteria. And because it was my first brew, I didn't know about it and let it work it's way for a few weeks. We did bottle the result and well, let's just say I was never able drink it. The taste was awfull and even worst, they were priming bombs (but that was because of something else 8).

I would suggest to put your yeast. Worst case, you will have lost the price of your yeast (which is a lot less than the price of your batch).

 

[brjohns3]

Thanks for the quick response! I'm glad you agree there's still hope haha. One last thing, I added two gallons to my carboy, then the wort (at about 80 F), then the yeast, and topped it off with water, did I need to stir this? Or is stirring unnecessary?

 

[Paradigm]

80 is still a bit high, you want high 60s ideally. Stirring is unnesscary no worries

 

[boydster]

I'm pretty sure your yeast won't be killed due to the heat until the temp gets up above 120F (I read 124 the other day, would need to look to see where, but I've heard 125-130F for ale yeast before) but the problem you run into is heat shock when you pitch into wort that is more than 10-15F different than the yeast temp. In this case, the yeast was warm and you pitched into a cooler environment, so it will want to go dormant, making it take longer before it actually gets started fermenting.

As mentioned earlier, 80F wort temperature is warmer than ideal too. If the yeast get started while the temp is still above the ideal range, the fermentation will be fast and generate a lot of heat, making it very hard to control the temperature and resulting in off flavors.

The best thing to do is rehydrate according to manufacturer instructions, and then temper the yeast slurry by adding small amounts of cooled wort (low-to-mid 60's usually, but check your strain and get it cooled to the lower end of the ideal range) to help bring the temperature down to within 10F of the wort temperature. That ensures the least amount of stress and helps get your yeast working quickly and cleanly.

 

[BigFloyd]

It sounds like he was doing partial boil, got the wort to 80*F and combined that with his top-off water. If the top-off water was chilled, he may have actually ended up in the sweet spot of ale pitching in the low 60's.

Like boydster, I am a bit concerned that he failed to attemperate the rehydrated yeast slurry and badly shocked the yeast by taking it quickly from 110*F+ perhaps as low as into the 60's.

 

[brjohns3]

BigFloyd is correct, it was a partial boil. Also, the yeast solution started at about 115 F, but it sat at room temperature for about 15 minutes, I would assume it cooled a bit before I added it, so maybe I just shocked the yeast, as opposed to killing it...you guys were also right about not needing to panic so soon, as I am beginning to see some small bubbles forming, and a bit of flocculate beginning to form on the surface. Maybe I'll still get some halfway decent beer!

 

[BigFloyd]

BigFloyd is correct, it was a partial boil. Also, the yeast solution started at about 115 F, but it sat at room temperature for about 15 minutes, I would assume it cooled a bit before I added it, so maybe I just shocked the yeast, as opposed to killing it...you guys were also right about not needing to panic so soon, as I am beginning to see some small bubbles forming, and a bit of flocculate beginning to form on the surface. Maybe I'll still get some halfway decent beer!

Good to hear.

I'm a fan of rehydrating dry yeast to obtain the best cell count, but it's better to pitch it dry into wort than to try and rehydrate if you don't follow the steps well.

 

[brjohns3]

Maybe I spoke too soon. My OG was 1.048, and now (15 days later) I'm at 1.021...I was expecting 1.010-1.012. Am I screwed?

 

[Euphist]

Give it another week or two and check again.

Sent from my GT-P3113 using Home Brew mobile app

 

[brjohns3]

It's been close to a week, and I'm still at 1.021-1.022.

Do I have any other options?

 

[kh54s10]

With extract brews it is fairly common for the FG to end up around 1.020. If you are concerned, swirl the fermenter gently to rouse the yeast and increase the temperature a little and see if you get any further fermentation.

My guess is that it is done.

 

[boydster]

Try warming it up a few degrees and rousing the yeast, if you haven't already done so. If that doesn't drop it any lower, it's done. Did you measure FG with a hydrometer or did you use a refractometer?


Edit: kh54s10 beat me to the draw... I should have refreshed before I posted.

 

[brjohns3]

I have a refractometer. I swirled it for a few minutes, the airlock jumped around a bit, but no activity since then. I guess it's as done as it's going to get. Thanks for all the responses!

 

[boydster]

I have a refractometer. I swirled it for a few minutes, the airlock jumped around a bit, but no activity since then. I guess it's as done as it's going to get. Thanks for all the responses!

You need to correct the refractometer reading for the presence of alcohol. There are conversion charts and calcs if you dig around - you may find that you are in better shape than you thought.

 

[BigFloyd]

I have a refractometer. I swirled it for a few minutes, the airlock jumped around a bit, but no activity since then. I guess it's as done as it's going to get. Thanks for all the responses!

Like boydster said. If you're using an uncorrected refractometer reading and it's 1.022, you're probably way lower than that. Once alcohol enters the mix, they read artificially high.

I compared it one time last year. Same sample: refract=1.035, hydrometer=1.017

 

[NYShooterGuy]

I'm wondering if I killed off my yeast today. I removed a 1 liter starter from the refrigerator, gave it a quick stir, and then pitched it directly into my 80° wort. I never allowed the starter to warm up to room temperature before putting it into my wort, and now I wonder if I have any viable yeast cells left.