Harvesting Coopers Yeast - 2 Colours Of Yeast

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Hi All,

After having 2 x 1 litre flasks out on the kitchen bench for 4 days I had to combine them to fit in the fridge (put the contents of flask B into flask A). I've noticed there is a mid layer of darker yeast in the middle - anyone know what this means? I think this was from flask B, which was 1 1/2 days younger than the flask A.

When I swirl it I get a bit of fizz, but it's been going since last thursday so I think the yeast in flask A has gone through all the sugar (and is whiter) while flask B has a little bit to go - does this sound about right?

I plan to pitch this tonight into a double batch (recipe forum link: here ) and just want to make sure nothing bad will happen, as I'm dumping 5kgs of LDME into it.

unless the photograph is decieving there does not seem to be enough yeast there for a double batch.

Sorry cannot answer the colour question but can see the distinctive layers.
I always get 3 layers with coopers yeast, Like pictured whit on the bottom and top and a brown centre. I have noticed that the yeast in the bottle when you pour it out is very dark (not white like normal). I am not sure if they use a combination of 2 types of yeast or what.

As TB says there is not enough yeast there and people always complain about banana in the coopers I can tell you 80% this comes from under pitching as I pitched one (single batch) I used 3 stubbies and 600ml starter then I tipped that into a 1.1lt starter (so prob 4x the amount in the culture thread) fermented at 17 deg and got banana smell threw ferment but it went away very fast. I pitched same brew onto the yeast cake (the other half of the 42lts) and it had no banana threw ferment and was heaps cleaner.

My yeast cake was 20ml over the calculated mr malty pitching rate (think it it was 8mm of yeast in the bottom of a 1.2lt grolch bottle) so that would be heaps more then you have and also was for a single batch.
Agree with tropical that is doesn't look like enough healthy yeast, Darker Stuff is usually associated with either trub mixed into the yeast or dead/sick yeast.
The fizz is CO2 coming out of suspension, so its probably still fermenting, the cloudiness of the wort suggests that to me also. but i crash chill my starters generally for 24 hours to make the yeast settle before pitching, unless its a big strong flavoured beer.

I wouldn't waste the 5kgs of LDME as it looks like you'll be under pitching.
Id crash this starter overnight, make another 2L starter tomorrow,
decant the current starter and pitch the settled yeast slurry into the new starter, let that ferment fully. Crash chill it friday night.
Saturday Decant some of the starter and taste it to see if it taste good (not infected)
and then brew on the weekend.

EDIT: Sorry didn't read the Double Batch Bit, I was thinking for 20Litres. You'll need to guestimate the amount of yeast you currently have (refer Mr Malty Website) and work out how much you need from there. But as a VERY VERY general rule of Thumb I aim to have Min. 2 litres starter worth of healthy creamy yeast on a stir plate to pitch into the average 1045-1050 20 litre batch.

Ive done far too much under pitching in the past and am yet to experience an over pitch that i know of.
also will add there charst to bring the starter (or yeast) up to temp before pitching the yeast into another starter or into the fermenter as thermal shock might kill off alot of them yeast you have just grown up.
also will add there charst to bring the starter (or yeast) up to temp before pitching the yeast into another starter or into the fermenter as thermal shock might kill off alot of them yeast you have just grown up.

Agreed! I always forget a crucial bit of advice!
no worries I always do to. I think most of the time I don't make sense but that's another story :p
also will add there charst to bring the starter (or yeast) up to temp before pitching the yeast into another starter or into the fermenter as thermal shock might kill off alot of them yeast you have just grown up.

Fair comment but some sources suggest pitching cold yeast into slightly cooler than main ferment temp wort is ok but not the other away around. Eg. http://www.maltosefalcons.com/tech/cold-pitching-yeast

I had to do this recently when my cube was accidentally opened, the brew turned out really good.

+1 on OP building that starter up for a 40L brew. Alternatively, use it to ferment out 10L of brew then pitch 30L with the harvested yeast from the 10L brew (of course i don't know if you have the 40L brew ready to go etc or still in LDME form)
thanks for all the replies, I obviously didn't set up the 'instant notification' email thing properly so I thought nobody had replied. so, errr, I made the brew :/

a bad night on the brew I must say, mistakes, here is my shameful comedy of errors:
- added the rest of the LDME + dex to the fermenter post boil and not the last 5 mins of the boil (what was I thinking?!) should be OK though.
- yeast bottle got moved around and wasn't completely settled, so decantering it meant I was losing suspended yeast and ended up pitching almost all of the jar. It tasted OK, alcoholy but smelt more like beer than yeast
- didn't get the yeast up to 20c (was at around 15c). didn't leave it out of the fridge long enough, maybe 1.5 hours
- took a bad reading of the fermented temp, so some of the liquid was still at 25c when pitched
- while cooling the fermented in the sink with cool water + ice, overflow from the hot water service fills up the laundry sink, parts of the fermenter up to 35c (testing with an ifrared thermometer). At this point things are looking pretty grim!
- temp controlled fridge was not on, so I had to warm it up from 10c - grrr!

As it's a 23L concentrate, the OG was 1.118 (OG from Ians Spreadsheet was 1.092, it did go up from 1.112 to 1.118 after 10 mins or so) ! There may have been a smidge over 5kgs of LDME + a bit from the starter but I didn't think it would be so high.

probably not going to ferment out and even if it somehow defies the laws of good brewing it'll taste like sour piss is what I'm thinking.

I think this one will go down as a learning experience...should I get another starter going to try to save once I observe what happens over the next 3-4 days? Should I post this back in the kits and extract section instead?
in terms of the volume of yeast, the jar had a 4.5cm radius and the yeast was around .7cm to .9cm in height.
in what can only be seen as a stroke of luck this brew turned out well! The yeast looked knackered (was very dark and sludgy) and my readings were still in the 1.020 range, I thought I was going to be pouring 50odd tallies down the sink. These readings must have been have both been off...hmm...fantastic creamy white head, golden colour and only a tiny hint of a errrr....homebrew taste, WIN!

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