Yeast Casse - some thoughts

[evanvine]

These are just some observations and thoughts on my part with regard to Yeast Casse.
Firstly I quote Nick Poulter who used to run a commercial vineyard on the Isle of Wight in his second book entitled “Wines from your Vines”.
“ Never allow the wine to rest on the old yeast for longer than six weeks or you will run the risk of a yeast casse, easily recognised by a disgusting “ mousey” flavour and after taste in the wine. This is caused by the enzymes in the yeast digesting the yeast cells themselves and the results are disastrous.”

Many wine makers on this Forum say that the wine should not sit on the lees for more than two weeks, I wonder if there is a difference here between “ grape” and “country” wines?

When we make Beer and Cider we deliberately “prime” the product with sugar to induce a secondary fermentation.
Whether it is bottled or kegged, the beer or cider can sit on the yeast from the secondary ferment from two months to over a year without any ill effects!

I again wonder if there is a difference between beer/cider yeast and wine yeast.

Can’t you tell I’ve got nothing better to do!

 

[unclepumble]

Jim looky here http://en.wikipedia.org/wiki/Autolysis_(wine) that should answer some of your questions.
And Here http://www.extension.iastate.edu/NR...A-AD16-778678B3E1CF/56377/yeastautolysis1.pdf
UP

 

[evanvine]

Thanks for that URL UP.
It certainly answers a question I didn't ask because I didn't know about it!

It still leaves 2wks versus 6 wks and why ale/cider are unaffected!

 

[unclepumble]

Thanks for that URL UP.
It certainly answers a question I didn't ask because I didn't know about it!

It still leaves 2wks versus 6 wks and why ale/cider are unaffected!

To be honest Jim I have never heard of Yeast Casse, however I have done some study on autolysis etc through work, and I have assumed that the 2 are the same thing, (someone shoot me for jumping to conclusions).

I cannot give you a definitive educated view I'm afraid.

I think the 2wks versus 6wks is to try and ensure no hydrogen sulfide is produced by the lees.

I think beer/cider are affected but the effects are more desirable in the finished products, hence 6-12 months ageing of certain beers and ciders.

I do know modern american style lagers are seperated from the yeast and pasturised as soon as possible after fermentation and a few days conditioning. to keep that "fresh taste"

UP

 

[evanvine]

I think beer/cider are affected but the effects are more desirable in the finished products, hence 6-12 months ageing of certain beers and ciders.

If that is true it would certainly explain the lovely smoothe rich taste you get in beer after a couple of months or so.
Maybe for the same reasons as champaign does in your URL.

 

[Aleman]

And then you have to consider wines '-sur-lee', That is That have been left to age on the lees for a significant time . . . like Muscadet.

I think the issue is not with the yeast per se but with the exteraneous gunk that we have in the primary fermenter . .. In beer you have the break protein, cider (even pressed) will carry over some pulp, and country wines will have a load of pulp . . . getting the young beverage off this in a reasonable time has to be considered a good thing. . . . And then you need to consider that even a traditional Burgundy will only have a couple of days fermentation on the pulp to extract the colour before being run off into fermenting tanks.

Yeast in bottles . . . or even cask is pretty much dormant, but it is not dying, it only takes one yeast cell to die and release its enzymes and then all of a sudden they all do it . . . in bottle conditioning (and champagne production) they really have a minimal amount of yeast . . . or should do . .. so that if autolysis occurs it does not taint the wine.

Just some random ramblings

 

[evanvine]

Just some random ramblings

Carry on AM, a lot of your ramblings tend to make sense when we can understand them. (grin)

 

[Moley]

Thanks for that UP, I never knew that stuff about Champagne. Then again, proper Champagne is wasted on me, I would much prefer an Asti, or even the sort of demi-sec Vin Mousseux you can buy in France for around 1€.

Personal opinion with the benefit of perfect 20:20 hindsight is that when I was making wine many years ago I frequently left it on lees for far too long and it did start to deteriorate, but internet didn't exist and I'd never even heard the word “autolysis”. This time around I tend to first rack 2-4 weeks after fermentation has finished. Any sooner, the sediment hasn't compacted and you lose far too much. If I add finings I will 2nd rack after 1-2 weeks, if I leave clearing to nature 2nd racking will be after 2-3 months. Wines which are left for longer-term maturation have no residue.

 

[Aleman]

Another thing that has an effect on yeast autolysis is of course temperature. . . the warmer it is the faster it is likely to happen . . . which is why generally wine and beer should be stored at a cool stable temperature, if it is going to be stored for any length of time.

 

[evanvine]

which is why generally wine and beer should be stored at a cool stable temperature, if it is going to be stored for any length of time.

Ooops, that's another thing I do wrong, I'm not fit to be let loose on the Forum! (sheepish expression)

 

[Sean_Mc]

Interesting thread Jim.
Palmer briefly goes over the subject, but says he's left brews for several months with healthy yeast in a well-prepared wort in the primary fermenter without any evidence of autolysis.

 

[evanvine]

Palmer briefly goes over the subject

Could you enlighten my ignorance Sean and give me a hint who "Palmer" is?
The interest for me came with the "wine makers" not alowing their wines to sit more than a fortnight on the yeast and the "beer makers" deliberately encouraging their brews to sit for months on the yeast.

 

[Sean_Mc]

Sorry Jim below is a link, some of its outdated, still worth a read though

Click the orange enter button and it brings you to the beginning of the book

http://www.howtobrew.com/

 

[leondz]

The fantastic country wines book I have recommends a pretty similar schedule for all wines; stir daily for the first 10 days in primary fv (usually a lidded bucket), then rack away from the ****, to avoid necrotising grapes/fruit "contributing"; leave to secondary ferment in a 20 degree is place for about 4 weeks, then rack, and leave in the cool for a couple of months, and bottle after that (then leave for a year or two). There are always lees at the end of racking, and wonderfully clear wine above, but I've never noticed an off flavour at this point. I daresay leaving wine on the gunk from primary fermentation is a bad idea, though, and never do this, not even with kit wines. Is that the stage that Nick Poulter is referring to?

 

[evanvine]

Is that the stage that Nick Poulter is referring to?

Many thanks Sean, will have a look at that URL.

Leondz
He is refering to the "white wine ferment", which is normally over in 3 wks and the wine is then alowed to stand for 6 weeks before racking.

Sean, that URL's massive, can't read it now as I have to get ready for that four letter word!