GHW
I noticed that my homegrown first gold bitter had a markedly different taste to the chris Colby bitter I made with a similar recipe and the same yeast, wyeast 1318 London ale iii.

The Colby bitter was made with a fresh vial, the homegrown with a starter made from half a jar of two (or so) week old slurry recovered from the fv of the Colby.

The homegrown bitter is by no means off tasting or unpleasant, just more different than You'd expect from the recipes.

Now I've just made a starter from the other half of the jar of slurry (now probably 8 weeks old) and it's got the same 'different' smell as my homegrown (if you get my drift).

So the obvious suspect is the slurry. It's giving off a different profile to the fresh. Anyone else had this happen?

Is it:
Autolysing in the jar?
A factor of the original brew (though it wasn't potent or dark or anything)
Yeast mutating (seems unlikely)
Infected (unlikely given that it doesn't taste off)

What's going on?!
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Pesho77
as far as i know if its autolysing it would smell / taste meaty, it could be any of the other factors or a little bit of each, if its only 2 generations old it shouldn't be mutating.

 Could there be another yeast at work here, maybe a wild yeast ? or could it just be the temps ?

 Pesh
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Fermented Culture
I was going to say repitching yeast increases the esters from gyle to gyle then it starts to decrease again. For example John Kimmich explains that after a certain amount of repitches conan "hits a stride" (most likely more fruity esters).

However I don't know what the effect of doing starters in between repitching would do.

No way to tell apart from guessing. It could be that a yeast from your vessel, environment or even the wyeast packet has changed the profile. It could be fermentation, temperature, pitch rates, mixing etc. Was there much difference in lag time and fermentation profile? Does it taste like it has a hint of a previous brew? Did you pitch all of the starter?

BTW did you end up fixing that infection/bad brew from a while back?
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GHW
Thanks both.

Temps had not occurred to me but given that the slurry was stored in the fridge and the second starter made from it smelled the same, temps seems unlikely.
Both beers were also fermented in the same place (albeit without temp control).

No idea what it is. I can't decide whether to use the new starter or a pack of us05 on my zephyr. I wanted an English yeast but not the flavour profile I know I'll get from this starter...
The 05 will make a decent beer, again not the one I wanted.

Brewing tomorrow so I've got a choice to make!
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Fermented Culture
If you use us-05 for zephyr you could make an over sized batch and make a smaller volume beer with some of the starter yeast to determine if the flavour will carry through? Maybe ferment in a soda bottle/demijohn/growler/wine bottle for the test.
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Robert

Fermented Culture wrote:
I was going to say repitching yeast increases the esters from gyle to gyle then it starts to decrease again. For example John Kimmich explains that after a certain amount of repitches conan "hits a stride" (most likely more fruity esters).

However I don't know what the effect of doing starters in between repitching would do.

No way to tell apart from guessing. It could be that a yeast from your vessel, environment or even the wyeast packet has changed the profile. It could be fermentation, temperature, pitch rates, mixing etc. Was there much difference in lag time and fermentation profile? Does it taste like it has a hint of a previous brew? Did you pitch all of the starter?

BTW did you end up fixing that infection/bad brew from a while back?

Or, to add to the list, something like nutrient deficiency or too much/not enough oxygen.

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Simonh82
Just a thought. If you had a lot of slurry and then made a starter you might have a significant over pitch. This might lead to suppressed ester formation so could really change what a bitter turns out like.
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GHW
Thanks for suggestions all. The slurry had the same smell before the (second) starter was made, and the beer made from the first starter smells/tastes exactly the same, so I'm taking that as evidence that it'll definitely carry into the zephyr. Which would rule out the overpitch theory. Unless I overpitched in the first beer that used the fresh yeast...but I don't think so.

God knows. It's all speculation but I think I'll use the 05 tomorrow.

The zephyr uses decent amounts of interesting malts (pale,Simpsons imperial, caramalt) and nice hops (summer, ella, Victoria's Secret) so it'll not lack flavour.

Does make me think twice about keeping slurry though. I should be better at top cropping from a Krausen, I just don't like opening the fv !
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Hops_and_Dreams
I used 1318, made a 3 litre starter and split it into 3, kept 2 in the fridge. I used the second in my oatmeal stout, didn't notice anything when I made the starter from that, but wasn't really looking for anything. It's still conditioning and stout will cover most flavour anyway.

I agree with you, cropping from fermenting beer sounds a bit risky. Why not keep some from a starter, rather than from slurry?
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Clibit
I don't know what is causing the change, but I wouldn't be put off using slurry. I do it a lot and haven't had problems. I sometimes ditch slurry that smells wrong. 
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Pinto
GHW wrote:
I should be better at top cropping from a Krausen, I just don't like opening the fv !


Ah, stop being so anal about these things m8 😉 next thing, you'll be telling me you plan to use an airlock on your ferments [rofl]

There are plenty of amazing beers fermented in open vats - A quick scrape of an active krausen is unlikely to hurt 😉

Slurries can sometimes pick up odd smells and flavours from the previous ferment - especially if the old ferment had speciality grains, powerful hops, or you pick up a percentage of trub with your yeast.
Beer is like porn - you can buy it easily enough, but its so much more fun to make it [wink]
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EddtheBrew
Pinto wrote:


Ah, stop being so anal about these things m8 😉 next thing, you'll be telling me you plan to use an airlock on your ferments [rofl]

There are plenty of amazing beers fermented in open vats - A quick scrape of an active krausen is unlikely to hurt 😉

Slurries can sometimes pick up odd smells and flavours from the previous ferment - especially if the old ferment had speciality grains, powerful hops, or you pick up a percentage of trub with your yeast.

Yup , agree with that , if you're going to top crop , remove the first dirty head carefully, rouse and wait for the second head to form, DON'T crop if the second head is more than 24-28 hours old .
If you're bottom cropping ( a traditional continental method of cropping Lager yeast) ;
Carefully rinse the down the side and spray lightly over the top of the yeast bed to wash the dead yeast away into a bucket, then once the crap's off , the runnings should give you the more viable cells,
Hope that info is of some use ,
Cheers
Edd
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GHW
Yes all good info thank folks.
I’m going with the 05, I don’t want to make another beer that’s just like the last one!
Didn’t sleep all night due to the bloody wind blowing cans and dustbins down my road all night, so mistakes aplenty already.
Compounded by the temp reading on the grainfather going up and down liks a yo-yo. Settled at 67c now and mash is on.

Recipe is (too knackered to add percentages and alphas)

15L trumans zephyr clone (ish)

2400g Maris otter
240g Simpson’s imperial malt
150g caramalt

10g summer @60m
10g summer @10m
10g Victoria secret @10m
10g Ella@10m
15g Victoria secret@0m
15g ella@0m
20g Victoria secret dry hop
20g Ella dry hop

Yeast was meant to be Wyeast 1318 London ale Iii but am using US05 for aforementioned reasons!
Mash 60m @ 67c
1hr boil

OG 1045 FG 1012 ABV 4.4 IBU 36

The original is a red tinged pale ale with lots of tangerine pith bitterness and a mineral finish (London water presumably, so I’m ok there)
If you haven’t tried it I would recommend it, though I doubt you will see it outside London.
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