Keeping Yeast Active

[Strange Dog]

Hi,

I am on brew #2, which I put in the fermenter 2 weeks ago. Its a coopers lager but I used SAF 23 yeast. It is brewing at around 12-14 degrees. The OG was 1036. It has now dropped down to 1012 but I think it is slowing down and I am worried that it is going to end up as, god forbid, some kind of low alcohol beer.

Is there anything I can do to ensure I am getting the most out of my expensive yeast (I blew $6 on it). I am sorely tempted to just stir the entire contents of the fermenter to wake up the yeast, is this wise? Or should I rock the fermenter and swish the contents around? Or is it too early to be concerned ?

My previous brew was the same kit (but I used the provided yeast) and it came out flat. I am paranoid that that is going to happen again.

 

[esssee]

I can't really comment with any authority, as I haven't done a Lager yet, but just a few points.

1. Yep, should be no problem swishing the fermenter to rouse the yeast a little.

2. I would have thought that with the lower temperatures of a Lager fermentation, a healthy starter would be needed to lift (read Double), the cell count of your yeast.

Check out You Tube for "Yeast Starter" for some guidance.

I would be interested in the comments of the more experienced members, as I am looking at doing a Kolsch in the near future.

 

[yum beer]

what did you add to the kit?

 

[Strange Dog]

I added the can of Coopers Lager extract, 11g of SAF 23 yeast, 1kg of dextrose.

 

[Pennywise]

I'd start with just raising the temp a little. You'll be fine to ramp a little at this stage, 18c won't hurt an will actually benefit

 

[fcmcg]

Hi,

I am on brew #2, which I put in the fermenter 2 weeks ago. Its a coopers lager but I used SAF 23 yeast. It is brewing at around 12-14 degrees. The OG was 1036. It has now dropped down to 1012 but I think it is slowing down and I am worried that it is going to end up as, god forbid, some kind of low alcohol beer.

Is there anything I can do to ensure I am getting the most out of my expensive yeast (I blew $6 on it). I am sorely tempted to just stir the entire contents of the fermenter to wake up the yeast, is this wise? Or should I rock the fermenter and swish the contents around? Or is it too early to be concerned ?

My previous brew was the same kit (but I used the provided yeast) and it came out flat. I am paranoid that that is going to happen again.

Mate...
First thing i need to say..RELAX....
Now listen...your only on your second brew and you have just begun a long journey....
Before you do anything , you need to understand why , we as brewers , do things and how our brews behave....but Rome wasn't built in a day and brewing knowledge won't be gained in 2 brews or off the internet , in my opinion....but you will get there...if you persist and do some research and ask questions...as you have already done
So...
Most lagers take at least 3 weeks to ferment(imho) , especially at that temp...well done on using the right temp for your lager..this is a good start
Your beers starting gravity and ending gravity set your alcohol ....so your starting gravity was quite low....so yes...if your beer finishes at 1.010 , then you will have a beer that is about 3.5% alcohol....nothing you can do about it...adding extra sugar now won't make it stronger...but learn and ask why yout OG was so low...did you add alot of water to your kit ?
You say you want to get the most out of your yeast....with a lager at that temp , you should have pitched 2 pkts...but hey..your just starting out and you have much to learn , grasshopper...don't worry about making a starter , especially with dry yeast...just use 2 pkts and "re-hydrate"
Don't stir the beer...you may well oxidize it and then it may taste not the best....your better off GENTLY swishing the fermentor to try and rouse the yeast and raisng the temperature too...having said that , your probably that close to being done at 1.012 , its not funny. Pennywise is right...rasing the temp could benefit...oneday if you ever go All grain...you will do this when you make a grain lager...it's called a diaceytl rest...but you don't need to worry about it at this stage...all you need to know is that rasing the temp at this stage will promote some more yeast growth to finsih off any residual sugar..which we've already established there isn't much left...
I recomend you really just relax and enjoy the ride....have i said relax enough ?
You say your last beer came out flat...how much priming sugar did you use ? How long was it between bottling and tasting ? How warm was it after it was in the bottle ? did you give it enough time ? Maybe some more details could help us , help you
Good luck with it...
Hope i've helped
Ferg

 

[Yob]

Don't stir the beer...you may well oxidize it and then it may taste not the best....your better off GENTLY swishing the fermentor to try and rouse the yeast and raisng the temperature too..

Its my understanding that o2 enters the wort from the surface... a swishing may lead to more o2 being absorbed than a gentle stir near the bottom given that there will be more activity on the surface.. or have I got that wrong?

having said that, unless you are whisking/shaking/stirring the crap out of it you are unlikely to get oxidisation from a 'careful rousing' of the yeast..

and +1 for raising the temps as a first attack (and relaxing)

Yob

 

[Nick JD]

If it's at 1.012 warm it up to 20C for a week. It's common practice when brewing lagers - called a diacetyl rest.

 

[QldKev]

As already mentioned, push the temp up to make the yeast finsih it all up.

Then once you hit your target gravity and it is constant, drop the temp cold for a week or more to lager it.

Once you have racked off the beer (bottled it etc) pour out half the yeast cake and brew the next lager onto it. So now your yeast cost has halved. Then do it again, and again Also that yeast cake you are pouring out from the first batch, pour it into a sanatised 600ml coke bottle and store it in the fridge. Don't store the yeast for many years, but it's a great way to kick off a new ferment.

You now have very cheap yeast.


The other Q, you said you had flat beer. How much sugar did you prime the bottles with?


QldKev

 

[Thefatdoghead]

Hi,

I am on brew #2, which I put in the fermenter 2 weeks ago. Its a coopers lager but I used SAF 23 yeast. It is brewing at around 12-14 degrees. The OG was 1036. It has now dropped down to 1012 but I think it is slowing down and I am worried that it is going to end up as, god forbid, some kind of low alcohol beer.

Is there anything I can do to ensure I am getting the most out of my expensive yeast (I blew $6 on it). I am sorely tempted to just stir the entire contents of the fermenter to wake up the yeast, is this wise? Or should I rock the fermenter and swish the contents around? Or is it too early to be concerned ?

My previous brew was the same kit (but I used the provided yeast) and it came out flat. I am paranoid that that is going to happen again.

Did you hydrate your yeast before you added it?
If you dont your most likely only going to end up with a 50% viable batch of yeast. Just throwing the yeast in the beer dry will kill half of the yeast. Also the other half wont ferment as well and the dead cell's will begin to admit off flavour to your beer. Read the manufacturers guide on rehydration of your yeast and if you do this you will find a much better fermentation at those low temps and a healthier yeast will no doubt give your beer a much better flavour profile. Because your just using kit and kilo it's quiet imperative to get a good healthy yeast started or your beer isn't going to taste very good at all.

 

[Strange Dog]

Thank you for all the replies.

For my previous flat brew I used carb drops as directed (2 drops per coopers long neck PET bottle). I kept the bottles in cardboard boxes in my kitchen for 2 weeeks before testing. It was flat then and it is still flat 3 weeks later. Not completely flat, just no where near the carbonation you would expect of anything carbonated. I am still drinking my way through it though so it's not awful, if anything the lack of bubbles make them go down a little too fast.

I have covered the fermenter with a blanket as I do not yet own a heat belt (I figured I would wait till next winter seeing as Canberras hot summer is just around the corner).

I did not hydrate the yeast, just carefully spread it over the surface of the wort. I believe I did add too much water to the brew. I was using a sachet from a home brew store that was 11g compared to the 7g you usually get in a coopers kit, so the home brew store guy said it would be more than enough. Next brew I will hydrate the yeast.

 

[Thefatdoghead]

Thank you for all the replies.

For my previous flat brew I used carb drops as directed (2 drops per coopers long neck PET bottle). I kept the bottles in cardboard boxes in my kitchen for 2 weeeks before testing. It was flat then and it is still flat 3 weeks later. Not completely flat, just no where near the carbonation you would expect of anything carbonated. I am still drinking my way through it though so it's not awful, if anything the lack of bubbles make them go down a little too fast.

I have covered the fermenter with a blanket as I do not yet own a heat belt (I figured I would wait till next winter seeing as Canberras hot summer is just around the corner).

I did not hydrate the yeast, just carefully spread it over the surface of the wort. I believe I did add too much water to the brew. I was using a sachet from a home brew store that was 11g compared to the 7g you usually get in a coopers kit, so the home brew store guy said it would be more than enough. Next brew I will hydrate the yeast.

Yeah mate you'll see a big difference if you re-hydrate the yeast. The pack you have wouldn't really be enough for a lager if you didn't re-hydrate because you want a 90% viability rate. Also depending on how long you lager for you might need to just add some of the coopers yeast when bottling time comes. If you lager for more than about 4 weeks or so you probably want to add 20 billion cells to get a good carbonation.
Cheers

 

[Strange Dog]

you might need to just add some of the coopers yeast when bottling time comes

I kept the coopers yeast in the fridge, and I also have another sachet of the SAF-23 available. How would i go about adding it prior to bottling, and how much should I add ?

 

[super_simian]

I kept the coopers yeast in the fridge, and I also have another sachet of the SAF-23 available. How would i go about adding it prior to bottling, and how much should I add ?

Nope. Don't do that. Just raise the temp to 18-20 for 48 hours, then drop it to 1-5 for 3 to 5 days (edit: well, actually you could properly lager at this point, but for bottle conditioned lager, I wouldn't bother. Perhaps "lager" the bottles after carbing fully.) Bottle with usual amount of sugar/carb drops, no added yeast. Make sure the bottles are 100% sealed, then leave them for a month at least - at or above the ferment temperature. Don't arse about with extra yeast or priming sugar. Just be methodical and exercise patience. If you reckon the first lot didn't carb, try storing them warm for a while. Warm, not hot. Like around 18-21. For a week to 10 days.

 

[jakethedog]

Its my understanding that o2 enters the wort from the surface... a swishing may lead to more o2 being absorbed than a gentle stir near the bottom given that there will be more activity on the surface.. or have I got that wrong?

having said that, unless you are whisking/shaking/stirring the crap out of it you are unlikely to get oxidisation from a 'careful rousing' of the yeast..

and +1 for raising the temps as a first attack (and relaxing)

Yob

If the airlock is on tight there will not be much O2 in the fermenter anyway - displaced by the CO2 from fermentation. Giving it a good stir should not cause oxidation as long as the fermenter lid has not been removed.

 

[Thefatdoghead]

I kept the coopers yeast in the fridge, and I also have another sachet of the SAF-23 available. How would i go about adding it prior to bottling, and how much should I add ?

sorry mate didn't mean to confuse you. Adding yeast for bottle conditioning would only be needed if your lagering for more than 1-2 months where the yeast wouldn't be very viable after then.
If your current brew is only lagered for a short period ie. a couple of weeks the yeast should be ok, although as you pitched the yeast when it was dry it's vitality has most likely suffered because of this. Also under pitching yeast can cause higher levels of fusel alcohols and esters. One likely reason your ferment has been slow could be due to under pitching. If you decide to reuse the yeast in your current ferment it's likely that the yeast will follow the same pattern of sluggish fermentation and some unwanted flavours.
The point is if you treat the yeast right and pitch at the correct rate for your given amount of wort and original gravity and keep the temperature stable give or take 1 to 2 degrees then you will end up with a much more palatable beer. Re-hydrate your yeast maybe 2 packs for a lager depending on gravity of wort and yeast viability in pack and you should see better results next time.