Questions regarding Cooper's Commercial Ale yeast.

[Nostrodamus85]

Good evening fellow home brewers, I have some questions regarding the use of CCA yeast. 

About 8 days ago I attempted to brew the Coopers Best extra stout recipe.

I followed the instructions regarding harvesting CCA yeast. I used 6 bottles of Mild ale (dated best after 1/7/21) in 60g DME and 600mL water.  After 2.5 days I let it sit in the fridge. There was a good amount of slurry at the bottom of my sanitised Demijohn. I let it sit in the fridge for about half a day. 

I pitched into a wort of 21 degrees as recommended in the BES recipe. The only difference in the recipe was that I added water up to 21L instead of 20L to drop the temperature. The OG was 1.054-1.055

The ferment started off nicely. An eruption after about 12 hours and had been bubbling away nicely for around 6-7 days. I got a hydrometer after day 6 (Sunday) and it was 1.030. I checked today and it has dropped to 1.028! The ambient temperature in our house sits around 19 and does not really fluctuate. 

Have I underpitched this ferment as it is a slighter high OG? Was the yeast in the bottles too old and not as viable because of the date of the beer? Has the yeast been shocked due to the decrease from 21 to a steady drop in temperature down to 19 degrees

I have read some posts where a 2 L starter is made. How would I do this from the above method of harvesting?

Sorry about all the qustions but any help would be greatly appreciated!

[iBooz2]

What size bottles were they, 740 ml or 375 ml etc. ?

Yes it was an under-pitch going on your 1.055 gravity wort.   You should have done the 60 g DME in 600 ml then stepped it up with a second stage starter of 100 g DME in 1 L to generate and get enough cells for your beer.

 

[Nostrodamus85]

Thanks for the advice. 

Yeah, They were 375mL bottles. 

So should I just wait and see if it drops slowly until comes down closer to the FG (it has been 8 days so far) or should I add the prepacked dry yeast that comes with the stout LME?

[iBooz2]

How quick can you do another 6 x 375 ml stubbie starter just like the first 60 g in 600 ml?  It will not hurt to throw some fresh yeast in there to help out at this stage to help finish it off.

I have not brewed a stout but have used CCA yeast (from harvesting exactly as you have done) dozens of times and it is surprising how it just chug's away and gets the job done albeit on 1.045 gravity brews I have been very happy with it.  Let it chug away and do another starter in parallel if you can.

What is the predicted FG?

[Greenyinthewestofsydney]

CCA is a great yeast. If I had a choice of but one yeast to brew with and one only it would be the yeast I choose because it is versatile. But from about 20 batches of experience with it it is a finicky yeast.  Like you @iBooz2 I have had issues with fast ferments to 1030 then a chug away of 2 points per day till FG. It all comes down to the yeast pitch. I always overpitch this yeast now and it's done in about 5 or 6 days at 18c and gives that classic coopers taste. Too little yeast and you get pear esters. Too high a temp and you get pear esters. 

[Oldbloke]

If it took off, should be OK IMO. But another starter will not hurt. What about the yeast sachet? Just toss that in?

I've done a lot of stout. Not unusual to go 10 days and usually finish with a high sg. So relax and be patient. 

[iBooz2]

3 minutes ago, Greenyinthewestofsydney said:

CCA is a great yeast. If I had a choice of but one yeast to brew with and one only it would be the yeast I choose because it is versatile. But from about 20 batches of experience with it it is a finicky yeast.  Like you @iBooz2 I have had issues with fast ferments to 1030 then a chug away of 2 points per day till FG. It all comes down to the yeast pitch. I always overpitch this yeast now and it's done in about 5 or 6 days at 18c and gives that classic coopers taste. Too little yeast and you get pear esters. Too high a temp and you get pear esters. 

I have never noticed it finicky and I always pitch very low to start it off and then let it creep up to 20's C.  Too warm and you will get banana smoothie IMO and miss out on that classic Coopers flavour (not talking about stouts here just ales in general).

I would make another CCA starter over pitching the kit yeast as its not the same strain.

[Nostrodamus85]

Quote

20 hours ago, iBooz2 said:

How quick can you do another 6 x 375 ml stubbie starter just like the first 60 g in 600 ml?  It will not hurt to throw some fresh yeast in there to help out at this stage to help finish it off.

I have not brewed a stout but have used CCA yeast (from harvesting exactly as you have done) dozens of times and it is surprising how it just chug's away and gets the job done albeit on 1.045 gravity brews I have been very happy with it.  Let it chug away and do another starter in parallel if you can.

What is the predicted FG?

 

I have 5 stubbies left. I will do a yeast starter tonight and add it in. 

As far as the predicted FG, to be honest, I am kind of guessing based on posts I've read on here in the past. I have assumed  80% attenuation and FG is coming in at 1.011. 

I checked again today. The wort is extremely bubbly. I gave a sample a bit of a shake before I checked it in the hydrometer and the reading is now 1.024. I think I will still make a new starter and add some fresh yeast. Do you think I add the whole contents or should I decant the liquid part and only add the yeast slurry this time around?

Thanks again for the advice

[Shamus O'Sean]

13 hours ago, Nostrodamus85 said:

I checked again today. The wort is extremely bubbly. I gave a sample a bit of a shake before I checked it in the hydrometer and the reading is now 1.024. I think I will still make a new starter and add some fresh yeast. Do you think I add the whole contents or should I decant the liquid part and only add the yeast slurry this time around?

Your brew still seems to be moving.  Adding more yeast will not hurt it.  I would decant most of the liquid leaving enough to swirl up the yeast and pitch it into the brew.

[Nostrodamus85]

On 10/14/2021 at 8:08 AM, Shamus O'Sean said:

Your brew still seems to be moving.  Adding more yeast will not hurt it.  I would decant most of the liquid leaving enough to swirl up the yeast and pitch it into the brew.

So tonight, I pitched the decanted yeast starter, trying not to agitate the wort. Hopefully it will be enough yeast to ferment to the end and not cause too much oxidation of the beer. The hydrometer went down to 1.022, so yeah still slowly moving a couple points every 2nd day. 

[Shamus O'Sean]

2 hours ago, Nostrodamus85 said:

So tonight, I pitched the decanted yeast starter, trying not to agitate the wort. Hopefully it will be enough yeast to ferment to the end and not cause too much oxidation of the beer. The hydrometer went down to 1.022, so yeah still slowly moving a couple points every 2nd day.