US-05 vs kit yeast flavours

[Igoe]

I'm still fairly new to this HB game, so I like to experiment a bit, using Coopers kits mostly while I get the hang of it and learn what I like most.

My go-to brew is the Coopers APA, using 1kg BE2 as recommended. The first batch I did was virtually indistinguishable to my taste buds from the real Pale Ale.

 

I recently did 2 batches side by side, using different yeasts, so I that could compare them.

 

One had the kit yeast rehydrated, the other had US-05 rehydrated.

Both were fermented in a fridge at a steady 21° (using STC-1000), then CC'd for the last couple of days.

Fermentation of both was pretty quick, being completed in about 4 days.

OG 1.042 FG 1.012

I bulk primed at 5.5g/litre with raw (not brown) sugar.

They've been in the bottle now for about 5 weeks.

 

I'm still trying to develop my palate, but it seems to me that the US-05 batch has a bit of a citrusy finish that is not there with the kit yeast. I'm not that keen on it to be honest. The other one is delicious.

 

So... why would this be so?

And given my penchant for experimentation, are there any other yeasts I should try?

 

Ian

 

[BlackSands]

I like that you did a side-by-side experiment like this. It really is the best way to determine the impact that a particular variable can have on the process and final outcome. Different yeasts offer differing ester profiles so I'm guessing that's what you're picking up. However, US-05 generally has a reputation for being very clean (though not for some of us!), so I wouldn't have expected it to be the one with 'citrusy' notes, based on majority experience. It may have been different if fermented at 18ºC which I know a lot of people prefer.

 

As it happens, I'm a huge fan of the Coopers kit yeast myself and now use it in preference to US-05.

[ChristinaS1]

Hi Igoe. Well there is kit yeast and then there is kit yeast. Not all of the kit yeasts are the same. Are you familiar with this sticky:

 

https://club.coopers.com.au/coopers-forum/topic/14826/

 

Coopers dry ale yeast (which is different than their commercial yeast) comes in all of the Original Series kits, plus the English Bitter, and Canadian Blonde kits. It is a very robust, neutral yeast that is more tolerant of being dry pitched, under pitched, and brewed at fairly warm temps. Its attenuation rate is ~72% which is very middle of the road for an ale yeast. US-05 is also neutral but attenuates much higher, ~81%, similar to lager yeast. The resulting beers will be much drier.

 

The APA and Mexican Cervesa kits come with a blend of Coopers ale yeast and a third party lager yeast. I am not sure of its attenuation rate but estimate it is ~77% (mid-way between Coopers ale yeast and the average for lager yeasts). The APA yeast is my favourite yeast; I always use two packets and ferment it at 18C. I have had a lot of bad luck with US-05, especially if there is wheat in the recipe; I don't use it anymore. You mention using 21C for your side-by-side and but that is too high for both the blended yeast and US-05; I suspect that is why found US-05 fruity. You might want to repeat the test at 18C. At 18C I think you will find US-05 slightly cleaner than the blended yeast. I find the blended yeast slightly fruity and I am guessing that is because 18C is slightly warm for the lager portion. Coopers recommends 18C for the blended yeast because colder than that is too cold for the ale portion, and warmer than that is too warm for the lager portion.

 

The identity of the third party yeast in the Thomas Coopers line are all secret, but my personal guess is that the Bootmaker, IPA, and Family Secret are BRY-97, and that the Porter is S-04. No idea about the others. The attenuation rate of BRY-97 is 72%, same as Coopers yeast, but it accentuates hops more.

 

Cheers,

 

Christina.

[BlackSands]

It is a very robust' date=' neutral yeast that is more tolerant of being dry pitched, under pitched, and brewed at fairly warm temps. Its attenuation rate is ~72% which is very middle of the road for an ale yeast. US-05 is also neutral but attenuates much higher, ~81%, similar to lager yeast. The resulting beers will be much drier. [/quote']What's interesting about this for is that the Beersmith data I have put US-05 at @74% - but checking their spec sheet... 81% is mentioned, so I subsequently updated the info. I have 72 - 77% attenuation down for the kit yeast - info for which I got here:

https://www.brewtoad.com/yeasts/25910

 

In practice I never really noticed much attenuation difference between the two to be honest - in theory 05 should ferment a couple points lower but they both seem to give me quite similar results.

 

One thing I am actually trialling on a current batch is a US-05/Kit yeast blend - maybe best of both worlds without the issues I've had with US-05 on its own. So far...so good...

[BlackSands]

And given my penchant for experimentation' date=' are there any other yeasts I should try?

[/quote']There's plenty to choose from, for ales Nottingham is a very popular. I experimented a bit last year with alternatives but personally, in the end I really didn't find the results different or compelling enough to lure me away from what already works reliably and consistently. But there's certainly no harm in trying out new stuff!

[ChristinaS1]

One thing I am actually trialling on a current batch is a US-05/Kit yeast blend - maybe best of both worlds without the issues I've had with US-05 on its own. So far...so good...

 

Hmm, I'd be interested in results you may have using the US-05/Coopers yeast combo together with wheat. As I have mentioned elsewhere I used to find about one out of three batches made with US-05 and wheat had clove-like phenolic off flavours. My theory is that US-05 produces a tiny bit of the enzyme that can covert the ferulic acid in wheat malt into 4-VINYL GUAIACOL . Using the two yeasts may or may not reduce the level of 4-VINYL GUAIACOL below taste threshold levels. Please keep us posted BlackSands.

 

Regarding Nottingham, I am not a huge fan. I prefer the taste of Coopers dry ale yeast. The only time Nottingham really makes sense to me is winter time brewing under cool conditions. Coopers will not carbonate my bottles for me below 18C, but Nottingham will still carbonate bottles at 15/16C.

 

Cheers,

 

Christina.

[BlackSands]

Hmm' date=' I'd be interested in results you may have using the US-05/Coopers yeast combo together with wheat. [/quote']This particular brew has no wheat... as far as wheat goes, for me it's very much a case of 'once bitten twice shy'! But, you've got me thinking... maybe wheat is something I could try again with this yeast combo. It was a blonde ale that was an absolute 'band-aid' disaster that put me off the wheat + US-05 combo. Dare I risk another batch??

 

Regarding Nottingham, I am not a huge fan. I prefer the taste of Coopers dry ale yeast. The only time Nottingham really makes sense to me is winter time brewing under cool conditions. Coopers will not carbonate my bottles for me below 18C, but Nottingham will still carbonate bottles at 15/16C.

I have yet to use it myself... and while it's Winter performance has some appeal, but as I'd mentioned elsewhere, I'm also interested in trying out lager yeasts for my Winter ales. I realise now after this Summer just gone that my Winter brews last year probably never ever actually reached full carbonation.

[Igoe]

Thanks for all the feedback.

I didn't realise the Coopers kit yeast was an ale/lager blend.

 

When my current batch is finished, I might try the experiment again at 18°.

 

Ian

[Otto Von Blotto]

The yeast in that particular kit and one or two others is an ale/lager blend but not all of the kits contain this yeast. The OS series are straight ale yeast, and the other lines contain various ale and lager yeasts depending on the kit.