Wee bit of Olive Oil for a stuck fermentation?

[pjj2ba]

This hopefully won't be necessary as so far my beer is bubbling along well. I made an Imperial Alt - OG 1.102 (Dusseldorf yeast strain) and I just want to be prepared in case it decides to misbehave. This yeast is not one typically recommended for large beers. Obviously one does not want to add O2 to a fermentation in progess. I realize the original use for Olive Oil is in the starter, not the fermentor. I suspect though, that the OO might help to revive the yeast without adding O2, and would act in a manner as if one had added O2, but without the oxidation as, well, none is being added. I'm thinking one could dissolve a tiny bit of OO in some vodka and add that to the fermentor to help disperse it (and sanitize it). I doubt the amount of OO added will cause problems with head retention. Even if so, I'm doing some head retention experiments that would take care of any problems. I could autoclave the OO, but then I'd still have the problems of dispersing it.

So, has anybody out there tried this, or thought about something like this?

For the chemists out there, I realize one does not need O2 for oxidation, just something to strip away electrons/H+. If the added fatty acids are involved in an oxidation process (thus becoming saturated), it would be in a controlled biochemical process, very different from the oxidation via O2 and free radicals.

 

[Edcculus]

I highly doubt that would work. The original study was to see if STORING yeast in olive oil would substitute for aeration. It has to do with the compounds yeast need when reproducing. Even though people have tried it, I dont think the study ever intended olive oil to be added directly to wort or beer.

 

[Jester369]

I highly doubt that would work. The original study was to see if STORING yeast in olive oil would substitute for aeration. It has to do with the compounds yeast need when reproducing. Even though people have tried it, I dont think the study ever intended olive oil to be added directly to wort or beer.

Are you sure? I thought BYO did an article on fermenting with it.

 

[Edcculus]

Are you sure? I thought BYO did an article on fermenting with it.

hmm, I remember seeing that online. I just assumed it was a more reader friendly version of the report put out by the guy that did the research with New Belgium.

 

[PseudoChef]

The addition of OO during the starter is so that the yeast produce the sterols necessary for its reproductive cycle. I believe that since the yeast will have already gone through this process (which it should do before fermentation actively begins) then it will not help the yeast finish it off.

 

[Edcculus]

Also, you don't really want the yeast to go BACK into the reproduction phase once fermentation has started. You want them to continue to eat the sugars. If your yeast crap out, they aren't eating the sugars and they sure as hell won't start reproducing again. I bet you will be fine, but I would look into other ways to unstick a fermentation.

 

[navysnail]

i would let the alt yeast go as far as they can, i dont think you will have a problem with it anyway. if it doesnt dry out like you need it to, then i would go with a more alcohol tollerant yeast if and when your original stops. i think it will be fine though, maby just a little slow if anything

 

[pjj2ba]

I guess the ultimate question is what is (are) the cause(s) of a stuck fermentation, and then what to do to prevent it.

Certainly too high an alcohol content can kill and/or severely inhibit the yeasts metabolism. For a given yeast strain probably the only way around that would be to add a more tolreant strain towards the end of fermentation.

Assuming though the yeast are still healthy, what could it be.

Premature flocculation. - swirl the fermentor occasionally to resuspend the yeast.

Are the yeast running out of other required nutrients? I'm talking various minerals, vitamins and other cofactors.

If a healthy amount of yeast was pitched and there was very little reproduction, then there should be plenty of these around. These are all cofactors used for enzymatic reactions and for certain structural components. As such, they are not consumed, but are used over and over again (Ca will always be Ca, it doesn't get used up - once repoduction has stopped)

It is possible that the cell membranes of the yeast have lost some of their integrity resulting in the loss of metabolic activity. Adding some OO would allow the yeast to replace any sterols in the membrane (hard to do with no O2 around). The membrane of any living cell is not static, it is dynamic. It is not a one time need for sterols during cell division. Components are continually being added and removed. Some components are recycled, others must be made again from scratch - if the cell still can. As cells age, they loose membrane integrity and will eventually die (like our skin cells). The whole anti-aging skin industry is based on prolonging skin cell membrane integrity.