Coopers Yeast

[dicko]

Hi brewers,

I have done a search but cant seem to find an answer to my query.

I have brewed on many occassions, the CPA clone using Andrew Qld's recipe and a recultured yeast from a few stubbies of CPA.
Until now I have allways got around 75% attenuation from the cpa yeast with a mash temp of 66 deg c.

Now nothing as far as the recipe has changed but I have recently aquired a stir plate and I built the yeast starter using it by stepping up to a three litre starter rather than using the old method of a shake when I walk past the starter flask.
I put a brew down the other day and the fermentation took of violently.

It ran rampant for about three days and I had trouble trying to bring the fermentation temp back to 20 deg c.
The beer is now finished and according to my hydrometer and Promash I have got 85% attenuation.
This has made the beer a lot dryer than usuall and the hop bitterness is lasting a lot longer on the back of the tongue than it normally does.

What sort of attenuation do you guys and gals get from this yeast normally and would the extra attenuation be caused by the use of my stir plate?

Cheers

 

[AndrewQLD]

I usually get around 75-78% real attenuation Dicko and I use a stir plate, I've no idea why you would see a jump in attenuation unless this yeast you used is say generation 3 or more, if you have been repitching from previous fermentations it could have changed and become more aggressive.
I'm only shooting in the wind here.

Andrew

 

[dicko]

I usually get around 75-78% real attenuation Dicko and I use a stir plate, I've no idea why you would see a jump in attenuation unless this yeast you used is say generation 3 or more, if you have been repitching from previous fermentations it could have changed and become more aggressive.
I'm only shooting in the wind here.

Andrew

Hi Andrew,

This starter was made straight from the yeast of four stubbies and built up from 500ml to 3 litres over 4 or 5 days.
The only thing that I can think of is that the stir plate made me more active amount of yeast than I would normally get and this caused the rapid take off of the fermentation.
BTW I have got a slight banana flavour from the higher temp at the start of fermentation but it is not over powering and actually quite nice.

I once threw a robust porter on top of a CPA yeast cake and it went off like a rocket but as the style is very forgiving it came out OK.

Cheers

edit spelling;

 

[crundle]

I have just built a stir plate and have noticed that I can get the same amount of yeast with a smaller starter now than the size I needed for the 'walk by and shake' method. Not too sure about the greater attenuation, but you would certainly have more and quite likely healthier yeast by this method.

Maybe for the next attempt build up a 2l starter instead on the stir plate, or for an experiment, have a comparison 3l starter going at the same time to see visibly how much more yeast you have from constant aeration.

I used to use a 3l plastic milk bottle for my starters and they worked great, but now find that a 2l Erlenmeyer flask does a better job by far (at least for ales it does, I make 2x2l starters for lagers now)

Crundle

 

[dicko]

I have just built a stir plate and have noticed that I can get the same amount of yeast with a smaller starter now than the size I needed for the 'walk by and shake' method. Not too sure about the greater attenuation, but you would certainly have more and quite likely healthier yeast by this method.

Maybe for the next attempt build up a 2l starter instead on the stir plate, or for an experiment, have a comparison 3l starter going at the same time to see visibly how much more yeast you have from constant aeration.

I used to use a 3l plastic milk bottle for my starters and they worked great, but now find that a 2l Erlenmeyer flask does a better job by far (at least for ales it does, I make 2x2l starters for lagers now)

Crundle

Hi Crundle,

The starter looked about the same size as I would normally have but maybe I could build it from say 2 or 3 stubbies only with the stir plate.

I have used the stir plate to build a few starters with Wyeast Thames Valley Ale as well and the three beers I have made with them have all attenuated at around the 76% which is as far as I know, pretty close to the mark.

The other only variable with this clone brew was that I used up 1 kg of Bairds GP with JW ale insted of all JW as I wanted to use up the bit of GP I had left.

Cheers

 

[bear09]

Hey guys. Just tapping into an old post here. Anyone had this before...

I made a 1L starter of coopers PA yeast from 8 stubbies dreggs. Lifted to 2L a couple of days later - STIR PLATE.

Pitched this yeast and normally for me after 24 hours it just about jumps out the fermenter to say hello BUT this time... a 1cm krausen. I left it for another day.... 1 cm krausen. The yeast didnt look active at all even though it went off on the stir plate.

On day three panic sets in and I do a gravity reading.... 1006 - what the hell??!!.... OG was 1048. Seriously it dropped 42 points in 3 days with a 1 cm Krausen....

Ive never had this happen before.... can any one share their experiences like this?

 

[manticle]

No idea about the krausen lack but coopers yeast attenuating fast and high matches my experience.

It's a beast of a yeast.