Unsaturated Fatty Acid as Oxy substitute

[Lyrebird_Cycles]

Though it's been around for a while, I've never tried it and I'm going to give it a whirl. More info here: http://www.kotmf.com/articles/oliveoil.pdf
note that at home brew scale the additions required are tiny and hard to do accurately.

The active principle of the olive oil is oleic acid, I happened to have a bottle of reagent grade oleic acid in the cupboard from when I was doing weird things with ferrofluid. Checked on the solubility and it's fairly soluble in ethanol, so I made up a 1% w/w solution in SVR.



This will make the addition a whole bunch easier, rather than trying to weigh out 4 mg of olive oil I'll be doing 0.4g of the solution (approx 0.5ml).

First xpmt will be in a two yeast Belgian brewing today, I'll play with comparing rates on future brews.

Anyone who wants to try this, I'm happy to send you a few ml of the solution since I've got enough oleic acid for a couple of megalitres of wort.

 

[yankinoz]

After reading the same thesis a while back I've tried the method using a very small quantity of olive oil and did no aeration beyond pouring from kettle into fermenter. Yeasts have included Notty, US-05 and BRY-97 and West Yorkshire liquid. For the latter I added the oil to the starter. Batches were 21--23L, OG from 1.048 to 1.054.

Lag times were under 12 hours, even with BRY-97, which has a reputation for long lags. On that limited evidence I can say that vigorous aerations weren't absolutely necessary to promote yeast reproduction.

Since I did no side-by-sides, I can't state whether there are some effects on lag time or any on flavour.

I will be interested in your more controlled experiments and would be grateful for a small amount of the solution. Keep in mind I only brew 12-15 batches a year and my youth is past.

 

[Lyrebird_Cycles]

I will be interested in your more controlled experiments and would be grateful for a small amount of the solution. Keep in mind I only brew 12-15 batches a year and my youth is past.

PM me your address and I'll send it out. I'll have to buy some smaller test tubes so it will be next week.

BTW the SVR is 95% ethanol so there's no need to sanitise this before adding to yeast.

 

[Bribie G]

Subject covered several times on the forum.

 

[sp0rk]

Subject covered several times on the forum.

Though 99% of the time people are just using olive oil
I found it worked alright for me, but whisking the fark out of the fermenter with a paint stirrer is my new favourite method
Will move to actual oxy later when I can be bothered

 

[Droopy Brew]

Subject covered several times on the forum.

Dont open it then.
First I have read about using an ethanol/oleic acid solution to replicate the benefits of aeration.
Maybe you could point me towards where this has been covered?

 

[Lyrebird_Cycles]

Another possibility is Tween 80 (polyoxyethylene sorbitan monooleate), which is about 20% by weight oleic acid. Although it's a surfactant, once the yeast cleaves the oleic acid off it should lose its surfactant ability and thus not affect head. The advantage of using Tween is that ergosterol is soluble in Tween so you could get UFA and ergosterol into the yeast at the same time.

I'm sure I used to have some Tween somewhere but I can't find it. I definitely don't have any ergosterol, so this will have to wait for another day.

 

[Killer Brew]

Given the cost and potential safety risks of using oxygen covered in another recent thread I will follow this with interest. Recent judging of my beers highlighted ferment flavours as the biggest opportunity for improvement and given I do appropriate size starters and have good temp control this is the area I will be looking at.

 

[peteru]

Funny that this should come up now. The last batch that I did on the weekend had a 2L starter where I added a single drop of extra virgin olive oil. No side-by-side comparison, but it certainly seemed to grow nice and fast on the stirplate.

I also went experimental on the water. This was Cooper's stout kit with an extra can of Cooper's Amber malt. I made this up to about 12 litres and aerated with a paint stirrer on a power drill, as usual. For the remaining 10 litres of water, I filled a cube container almost to the top and added 6ml of 6% hydrogen peroxide, mixed it and let it stand with the lid on for about 10 minutes. Then poured into the fermenter, followed by the yeast starter.

It was going nice and strong only 4 hours later.

Of course, no science there, just a case of "what would happen if". If it goes horribly wrong, I'll know not to bother with this. If the results are good, it may be time to design a slightly more controlled experiment to see what's what.

 

[sp0rk]

I can't wait until MHB gets here...

 

[Bribie G]

Oleic acid is the major component of olive oil.

However despite this topic being a long running one it's good to have someone with a scientific background giving it a whirl, and am also looking forward to the results.

 

[Lyrebird_Cycles]

Oleic acid is the major component of olive oil.

Yes, see the second para of my OP.

There is however a significant difference in that the oleic acid in olive oil is present as triolein (oleic triglyceride).

I decided to try straight oleic acid mostly because I could but also because it should be available to the yeast earlier since they don't have to deacylate the triglyceride.

Also my reading of the original paper says that they stopped at a relatively low level because they were afraid that excess triglyceride might affect head retention. This should be much less of a problem with the straight oleate, so I'm going to try higher levels than they did to see if it suppresses ester formation.

 

[MHB]

Using pure Linoleic acid has already been tested, as referenced in the original Hull Olive Oil Thesis View attachment hull-olive-oil-thesis.pdf
I am pretty sure people have also played with pure Oleic Acid too.

The one point I wish people would get their heads around is that this was done to yeast in storage, as is made very clear in the thesis.
The only time the genes required to take up fatty acids directly are expressed is when the yeast is in its dormant phase. There is no point to adding Oil/Fatty Acid to the ferment!
Mark

PS work was conducted in 2005 over 10 years ago, if it worked I think there would be a lot of breweries doing it. Not even New Belgium where the work was conducted.
M

 

[JDW81]

I prefer the tried and tested method of oxygenation with O2, rather than adding something to my beer that may potentially kill head retention.

If someone really wants to show it works, then do a double blinded, randomised controlled trial with identical worts, yeast and pitching rate etc with a sample size that is going to give you a statistically significant result, with the analysis done by an independent group of people (both chemical and sensory).

While the topic is interesting, the actual research doesn't really come up to muster with respect to design, methodology or statistical analysis.

IMHO it is a pretty average piece of research that doesn't prove anything.

JD

 

[Lyrebird_Cycles]

The one point I wish people would get their heads around is that this was done to yeast in storage, as is made very clear in the thesis.
The only time the genes required to take up fatty acids directly are expressed is when the yeast is in its dormant phase. There is no point to adding Oil/Fatty Acid to the ferment!


PS work was conducted in 2005 over 10 years ago, if it worked I think there would be a lot of breweries doing it. Not even New Belgium where the work was conducted.

I am sure you are wrong here.

The uptake mechanism has been closely investigated, see for instance http://www.ncbi.nlm.nih.gov/pmc/articles/PMC193871/
Yeast with deletions of the genes for fatty acid uptake are unable to grow in anaerobic conditions when the fatty acids are supplied where yeast that have the genes do grow, suggesting they are expressing the genes during growth.

I can find nothing in Hulls' paper or in the two cited papers by Moonjai that says that the genes are not expressed in growing cells, merely that the original research was done on addition to cropped cells. This was done to avoid perceived problems with adding FA to wort.

In this case the FA are also being added to the yeast. I don't see a significant difference between this and the methods used in the original work. The rate of uptake of FAs in Saccharomyces is known to be very rapid, see http://www.sciencedirect.com/science/article/pii/000527608490198X)

To your last point, I am not sure "no-one does it" correlates one-to-one with "it doesn't work". As noted above the original research was not of particularly high quality, also brewing seems to be full of people who think they already know everything.

 

[Bribie G]

Go, lyrebird, sock it to CUB good.

 

[Lyrebird_Cycles]

Actually when I was at CUB most of the people there were very good, in those days they had a first class research facility in the windowless bunker in Bouverie St.

Sadly those days are long gone.

Actually one of the people I remember from the research division was a bloke by the name of Mark, we were at a conference at Mt Macedon together and one morning we decided to run up the mountain. He nearly killed me.

Hey MHB, you didn't happen to be a world class Rogainer / 24 hour orienteer in your youth did you?

 

[JDW81]

To your last point, I am not sure "no-one does it" correlates one to one with "it doesn't work". As noted above the original research was not of particularly high quality, also brewing seems to be full of people who think they already know everything.

I suspect no one does it as it hasn't been proven to work. There may be theoretical reasons for it to be of benefit, but unfortunately theory doesn't always translate into results.

If there was good, scientific and sensory evidence that the beers produced were better than current practice then it may well be taken up by the industry, until then I suspect the naysayers will continue to naysay.

JD

 

[timmi9191]

Starting with:

I am sure you are wrong here.

Ending with:

.. brewing seems to be full of people who think they already know everything.

 

[Mozz]

Thanks for sharing this work, and explaining the chemistry.
Whether it works on a micro brew scale or not is moot.
There are no new findings without those doing the hard yards.