Olive Oil In Starter

[Supra-Jim]

ahh now lets really throw an interesting question into the debate...... will the olive oil work in something like a mead where constant oxygenation is a must. that would be some interesting testing

Is constant oxgenation a must for mead or is regular addition of nutrients necessary?

I thought it was the later, especially if as mentioned above that yeast in beer wort consume the necessary oxygen in 6-9 hours.

CHeers SJ

 

[hazard]

No you are right and wrong. If you look at the original thesis, they state that they did several tests, ranging from 1 ml of oil per 67 Billion yeast cells to 1 ml of oil per 25 billion yeast cells. A smack pack is 100 billion yeast cells, so this implies about 1.5 to 4 ml of oil would be added for one smack pack. I think packs of dry yeast are a similar size, so this is still OK. Therefore it appears to be spot on with 3 ml or less. They also added oil to starter 5 hours before pitching. (snip from Hazzard post on another thread)

Cheers

Chappo

Errrrrr - I might confess to an embarrasing error her. I've re-read the thesis and it actually states 1mg per 67 million yeast cells, NOT 1ml. One millilitre of oil is a bit less than 1 gram, ie 1,000 milligrams - so if quantities are measured in milligrams, then they are very much bigger than what was used by Hull. That doesn't mean that doseage used by Chappo is bad, as results to date are reported to be positive.

In Hull's work, results improved as the doseage got bigger, but he did stop at 1 ml (not mg!!) per 25 million cells. So what might happen if dose of oil is bigger? My guess is that yeast will metabolise oil up to a point, and once yeast are fully satisfied, any excess oil will simply float around in the fermenter. But I am an engineer, not a biologist, so don't trust me. I don't know how much oil yeast will use, but I guess that even if they used nothing, 3 ml of oil in 23 litres of wort is not going to do any damage.

So if true dose is 3 mg, not 3 ml - how on earth do you measure 3 mg?

FROM THE THESIS:

"Due to the variation in yeast slurry thickness the amount of olive oil used was based on the total number of cells instead of mg / L of yeast. In the 360 hl batch the olive oil was added to the yeast at a rate of 1 mg / 67 billion cells pitched (15 mg olive oil / L of yeast assuming a count of 1 billion cells /ml). In the 720 hl trial the concentration was increased to 1 mg / 50 billion cells and in the 2100 hl trials the concentration was increased again to 1 mg / 25 billion cells."​

 

[chappo1970]

If the yeast is dried, is it not conditioned to do its job without aeration?

You are 100% correct both Fermentis and Safyeast state on their respective websites that on first pitch aeration is not really required but good practice.

As an aside I have emailed both companies asking about Olive Oil and if they have done any study on the subject. I will be interesting to see if I get a reply?

Chappo,

Would not be possible to get a reasonable approximation (with an acceptable degree of error for the home brewer) by using a stir plate, air stone + cylinder, olive oil, same strain of yeast and same starter.

Your two variables would be 02 or olive oil and with the starter, you could get a reasonable approximation of the growth of the yeast (i.e without trub from a full fermentation). These could even be fermented side by side in a double batch split between two fermenters.

I think given (as you stated) the 'wiggle room' in our equipment etc, an experiement like this should be able to produce a resonably acceptable result. Evidence could be seen in the yeast grown in the starter and that could also be compared against the fermentation results (OG vs FG etc).

Food for though?

Cheers SJ

I guess it is possible. Here's my initial thoughts say I crack one 11gr sachet of Safale s05. Split it 3 ways evenly say 3gr a pop. If I was to do 3 starters and ferment them over say a 36 hour period that way it would run over a weekend and I could keep cloer attention to the experiment.
The 3 experiments would be say:

1. O2 only
2. Olive Oil only.
3. No aeration

Wort comes from the one batch so it could be considered as a controlled source with the same OG and fermentables available to the yeast. Ferment all 3 in my fermentation fridge so the climate for all three would be the same.

Does anyone know if I measured the 3 before and after, taking care to measure all liquid additions carefully and accurately, for weight would I be able to ascertain actual biomass from that and would that be an indication of a result or a complete waste of time?

I appreciate that this is Ametuer hour X 1000 but I willing to listen to anyone willing to chime in on how to do this better and or more accurately.

Cheers

Chappo

 

[Supra-Jim]

I don't know if weighing the samples will work, as they say 'you don't get nothing for nothing'. The increase in yeast cell mass should be proportional to the reduction in sugar/fermentable reduction in the sample, should it not??

A less accurate method could be to ferment out the starters and then chill them. Taking note of the depth of the yeast at the bottom of the flask. This could give you a volume of yeast grown.

BTW, if you use the stirplate you mentioned you have planned (I have one under construction at the moment), you should bew able to grow a good sized starter in 24 hours. Although you are starting with 3gms each sample so yeah try 36.

Then ferment the three batches side by side and see which one wins!!

Cheers SJ

 

[mika]

Does anyone know if I measured the 3 before and after, taking care to measure all liquid additions carefully and accurately, for weight would I be able to ascertain actual biomass from that and would that be an indication of a result or a complete waste of time?

Not without breaking the laws of Physics. If you could somehow drain off only the liquid and keep all the yeast, then somehow dry it and measure it's mass, you might get close. But a lot of variables within it.

Edit: Beaten to it...

 

[JonnyAnchovy]

Errrrrr - I might confess to an embarrasing error her. I've re-read the thesis and it actually states 1mg per 67 million yeast cells, NOT 1ml. One millilitre of oil is a bit less than 1 gram, ie 1,000 milligrams - so if quantities are measured in milligrams, then they are very much bigger than what was used by Hull. That doesn't mean that doseage used by Chappo is bad, as results to date are reported to be positive.

In Hull's work, results improved as the doseage got bigger, but he did stop at 1 ml (not mg!!) per 25 million cells. So what might happen if dose of oil is bigger? My guess is that yeast will metabolise oil up to a point, and once yeast are fully satisfied, any excess oil will simply float around in the fermenter. But I am an engineer, not a biologist, so don't trust me. I don't know how much oil yeast will use, but I guess that even if they used nothing, 3 ml of oil in 23 litres of wort is not going to do any damage.

So if true dose is 3 mg, not 3 ml - how on earth do you measure 3 mg?

FROM THE THESIS:

"Due to the variation in yeast slurry thickness the amount of olive oil used was based on the total number of cells instead of mg / L of yeast. In the 360 hl batch the olive oil was added to the yeast at a rate of 1 mg / 67 billion cells pitched (15 mg olive oil / L of yeast assuming a count of 1 billion cells /ml). In the 720 hl trial the concentration was increased to 1 mg / 50 billion cells and in the 2100 hl trials the concentration was increased again to 1 mg / 25 billion cells."​

Glad this has been cleared up. I've been scratching my head while following this thread trying to work out precisely how people came up with the 3ml figure. Thought I had it nailed in the other thread (below), but I've often been known to be out by several orders of magnitude in my calculations!

I think this was one of the orignal articles outlining the process. in the experiemnt they do a 360 HL batch with 15ML of Olive oil, if i'm not mistaken that'd mean around 0.01ml for a regular 22L batch.

Someone please correct my math!

I'd be reluctant to overuse oil, particularly in largers, because most of the accounts report higher ester production when using olive oil.

 

[technocat]

If you use water as a medium of mass 1ml = 1000mg You would have to determine the mass of olive oil to arrive at the true answer. All academic really not much in it unless you were brewing in a big way. I am just a retired Electronics Tech so not that much in to it from a biological point of view.


Cheers

 

[JonnyAnchovy]

Why doesn't someone get their act together and genetically engineer the ultimate yeast that never needs aeration, always attenuates to the perfect level, flocculates into a solid repitchable brick at the end of fermentation (leaving behing crystal-bright beer), seeks and destroys all foreign bacteria/spores, and generates the exact same flavor profile at any temperature?

Why are we wasting our time making disease resistant plants and high yield crops when we could be working on something much more urgent like this??

 

[chappo1970]

Ok what about these two ideas then?

1. Kill the yeasties with say 10mls of chlorine solution causing them to drop from the solution. Draw off as much liquid as possible and weigh the results? A centrefuge would no doubt help. Hmm what can I jerryrig?
2. Give them 24 hours and then measure the amount of sugar that they have eaten?

Cheers

Chappo

 

[Supra-Jim]

IF you kill them, then you can't add them to a wort and give them a field test with a full fermentation? yes?

I see this experiment in two parts. One, see how much yeast can be grown in a given starter in a given time (with variables mentioned by Chappo earlier).

Then two, ferment a full batch and measure results.

Cheers SJ

 

[chappo1970]

IF you kill them, then you can't add them to a wort and give them a field test with a full fermentation? yes?

I see this experiment in two parts. One, see how much yeast can be grown in a given starter in a given time (with variables mentioned by Chappo earlier).

Then two, ferment a full batch and measure results.

Cheers SJ

Agreed but I thought I might take down one debate at a time. So by doing a starter only test and then move on to a fermentation test later on.

Really I am only going to waste say 3lts of wort and 1 sachet of yeast to do this initially but I should really do it at least 3 times to see whether the results are repeatable and represent the overall trend of outcome, No?

Cheers

Chappo

 

[Supra-Jim]

Yes, it would be good to repeat the process (3 times is good). That way you more evidence to back your claims/results.

Cheers SJ

 

[Leigh]

Not having read the thesis (I will with time), but is the term "olive oil aeration" used at all, or is it "olive oil to replace aeration"?

Also, does the author provide dissolved oxygen concentrations in the wort as a function of time with a comparison of the olive oil method and another aeration method?

Were the different "batch" sizes performed in the same vessel? Was the surface area the same?

Being a scientist, I suspect (and will stick my head on the block having not read or skimmed the thesis) that the olive oil does not act as a nutrient as implied above (far too small a concentration), but rather acts as a surfactant, reducing the surface tension of the wort and therefore allowing more oxygen to be absorbed through the surface...this could theoretically allow the yeast access to more oxygen over a longer period (easily proven by measuring DO as a function of time with back-to-back treatments that are otherwise identical), accomodating the yeasts requirement for oxygen (which can not miraculously be replaced by anything with another name).

Given my hypothesis, I would suggest that at some point, the olive oil would stop acting as a surfactant (probably at concentrations where it is no longer miscible in water) and form a seperate layer, potentially slowing the absorption of oxygen.

Now for those who have read the thesis to shoot me down in flames LOL

 

[brettprevans]

very interesting leigh. why dont you make up some controlled trials and bring them to the caseswap for testing by the expert panel.

seriously, it is interesting.

 

[JonnyAnchovy]

Not having read the thesis (I will with time), but is the term "olive oil aeration" used at all, or is it "olive oil to replace aeration"?

Also, does the author provide dissolved oxygen concentrations in the wort as a function of time with a comparison of the olive oil method and another aeration method?

Were the different "batch" sizes performed in the same vessel? Was the surface area the same?

Being a scientist, I suspect (and will stick my head on the block having not read or skimmed the thesis) that the olive oil does not act as a nutrient as implied above (far too small a concentration), but rather acts as a surfactant, reducing the surface tension of the wort and therefore allowing more oxygen to be absorbed through the surface...this could theoretically allow the yeast access to more oxygen over a longer period (easily proven by measuring DO as a function of time with back-to-back treatments that are otherwise identical), accomodating the yeasts requirement for oxygen (which can not miraculously be replaced by anything with another name).

Given my hypothesis, I would suggest that at some point, the olive oil would stop acting as a surfactant (probably at concentrations where it is no longer miscible in water) and form a seperate layer, potentially slowing the absorption of oxygen.

Now for those who have read the thesis to shoot me down in flames LOL

interesting idea, but I think the olive oil works through a different mechanism. From the thesis:

"The reason the yeast needs oxygen for a proper fermentation is because it needs to synthesize sterols and unsaturated fatty acids (UFAs) for its cell walls ... One interesting alternative to aerating the wort is to add the UFAs directly to the yeast during storage. Theoretically the yeast should be able to take up the UFAs and use them in a subsequent fermentation without the use of oxygen. This should result in a beer that has better resistance to staling oxidation without adversely effecting fermentation performance or flavor." (pp. 8).

 

[technocat]

I have glanced through Hulls thesis and find the topic interesting and intend to give it a read in depth time permitting. The thesis does mention the problem that we all try to avoid and that is of oxygenation or staling of wort through aeration of wort during the brewing process particularly at high temperatures. However it is understood that this is not such a problem at fermenting temps and aeration prior to pitching yeast is advisable for healthy yeast viability. The subject of aeration in the brewing system has been covered here through other topics such as cavitation in ball valves, leaky unions, tubing, and any other place air can ingress. We accept the fact that oxygenation is a fact of life for good fermentation but I for one keep it to a minimum when pitching yeast. Do others who are critical of their brew experience staling as usually an after taste in otherwise a good beer. Occasionally I experience the wet cardboard taste very faintly as an after taste although not perceived in the first taste or aroma and this IMHO detracts from an otherwise excellent brew. The Olive oil theory is an attractive one as the way I see it it keeps roughing up the wort to a bare minimum. Any comments.
Brian

 

[sah]

Be very careful doing your measurements and recorded results, You probably don't have the gear to generate an accurate objective result.Im not saying OO doesnt have merit I just dont think you can do it justice.
GB

We've all got the gear to measure results that are relevant to us small batch brewers.

The benefit appears to be long term storage.

If someone is keen to experiment, split a batch, aerate half, olive oil the other half, pitch the same amount/type/health of yeast. Bottle and conduct blind side by side (even triangular) testing at intervals say 1 month, 3 months, 6 months, 12 months, 18 months.

regards,
Scott

 

[muckanic]

The benefits of not oxygenating could be difficult to detect in naturally conditioned beer. That oxygen has to get in and have an effect before it is consumed by the yeast (ie, we are not talking post-ferment aeration here), and the staling effect has to be non-reversible.

For my money, attenuation and byproducts would be the most practical indicators. Use a high gravity, intentionally bright wort that has not been allowed to absorb air post-boil. Deliberately underpitch and use closed fermentation. Test whether the lipidated brew (main batch only, not the starter) chokes in comparison to the oxygenated brew. Use a third comparison which receives neither lipids nor O2 just to ensure that we are brewing at pitching limits and that something chokes. Avoid dried yeast because it comes with glycogen reserves built up. All it takes is three 2L test batches and there could be a result in a week.

 

[chappo1970]

I am really liking all the idea's and thought's on this being put forward.

...For my money, attenuation and byproducts would be the most practical indicators. Use a high gravity, intentionally bright wort that has not been allowed to absorb air post-boil. Deliberately underpitch and use closed fermentation. Test whether the lipidated brew (main batch only, not the starter) chokes in comparison to the oxygenated brew. Use a third comparison which receives neither lipids nor O2 just to ensure that we are brewing at pitching limits and that something chokes. Avoid dried yeast because it comes with glycogen reserves built up. All it takes is three 2L test batches and there could be a result in a week.

I'm really liking this idea muckanic. Thanks for putting it up.

Although my initial thought was a lighter styled beer. My reasoning was that in a lighter styled beer there is very little to get lost in the body and or hopping of the beer. Say something like a SMASH (single malt and single hop) as we want to taste the difference between all 3. Also could be repeated by others willing to have a go and try it for themselves?

I agree that the use of a liquid yeast is a must. If it is a smack pack then it must remain unsmacked obviously.

Another question then arises should the starters be done equally the same as I would assume it would be best to come from the same batch of yeast?

Cheers

Chappo

 

[mika]

I have glanced through.... blah, blah blah
Brian

Interesting show on the Brewing Networks 'Brew Strong' program on Hot Side Aeration. Some scientist dude they interviewed (I'm a little vague on the specifics now in case you hadn't noticed) had done some research and back to back testing and came to the conclusion that while HSA was a potential issue, a good fermentation would 'fix' itself.
Based on that, I would say that any aeration pre-ferment, Hot or cold, shouldn't be an issue as long as you have nice healthy active yeast to ferment out your beer. Oxygenation after fermentation could prove to be an issue, but I don't see the Olive oil helping you in that instance.