Olive Oil - Testing

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luke2080

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The purpose of this thread is to create a standard test that fellow homebrewers can perform at home and post the results. Please keep any responses to your test results or ideas to improve the testing only. Opinions and arguements on this topic are already underway on another thread.

I'm expecting to record results from this testing until December 2013, at which point I'll publish the results here at HBT. However, if we have enough results coming in, I'll post it Quarterly.

The purpose of the test:
Quantify the impact to fermentation Olive Oil (OO) has on Final Gravity (FG) and taste, as compared to other known aeration techniques: No oxygen, splashing, aeration from aquarium pumps (AFP), and aeration from an O2 tank (AT). This is the homebrew version of Hull's analysis title "Olive Oil Addtion to Yeast as an Alternative to Wort Aeration". The main point of Hull's testing was to analyze the impact to longevity of the beer, an important factor for commercial breweries. Because I drink beer to quickly, longevity will not be tested.

Required equipment:
To perform this test, you must be able to create a starter. Equally split the starter into two measureable amounts (2 measuring cups), fermentors to split one batch equally to smaller batches, OO, and common sense. Optional equipment - aeration aquarium pump/stone & aeration from an O2 tank.

Process:
Create a proper starter for the beer you'd like to brew. 5 hours before you'll need to pitch the starter (generally before you fire up your HLT) split the starter into two batches. Or more if you are going to test more than 1 aeration technique. The starter can be chilled and decanted first, or the full volume. This does not matter, as long as ultimately all of the yeast is fully shaken up back into the solution/starter, and that this starter is now spread evenly per batch.

One starter should be given a miniscule drop of OO - again, 5 hours before it'll be required. This is difficult to measure, so I'd propose everyone do it this way: Put a bit of OO on a spoon. Over your sink, pour out that OO. Then put the spoon over your starter you wish to add this to, and hang it over until you get one drop to drip in. (If anyone is able to measure how much OO this is, please do). Also - sanitize your spoon first!

After you've brewed and chilled, split the wort into equal batches. There are 4 possible results to record: Using OO, Splashing to aerate, using aquarium pump, using O2 tank, and no aeration. You must at least perform 2 of these techniques with the same split batch and same split starter. If you have the ability to do more than 2 at the time, please do. Be sure to label your batches.

The length of time you ferment, temperatures, and other variables should be the same for all batches. How you control this does not matter (ferment at 80 degrees for all I care), just be sure all the versions from one batch test are under the same conditions.

Record the results in the following format:
Batch: 1-A
Beer Type: Hefeweizen
OG: 1050
FG: 1012
Method Used: OO, Splashing, AFP, AT, No O2
Oxygen parts per million (PPM): If you can measure this..I can't. Doubt any of us can.
Taste Results: 1,2,1,1,2
Did anyone taste OO?: Yes/No
Taste Test Method: Single Blind, Double Blind, Blind Triangle

For Taste Results, #1 is best. If you did 3 tests out of the same batch, people would blind taste test 1 through 3. If 5 people sample it, record all of their results for each batch. These will eventually be weighed for the final taste results across the HBT testing.

Each test should then at least have two sets of results, like so:

Batch: 1-A
Beer Type: Hefeweizen
OG: 1050
FG: 1012
Method Used: OO
Oxygen parts per million (PPM): N/A
Taste Results: 1,2,1,1,3
Did anyone taste OO: No
Taste Test Method: Single Blind

Batch: 1-B
Beer Type: Hefeweizen
OG: 1050
FG: 1013
Method Used: Splashing
Oxygen parts per million (PPM): N/A
Taste Results: 2,1,2,3,2
Did anyone taste OO: No
Taste Test Method: Single Blind

Batch: 1-C
Beer Type: Hefeweizen
OG: 1050
FG: 1014
Method Used: No O2
Oxygen parts per million (PPM): N/A
Taste Results: 3,3,3,2,1
Did anyone taste OO: No
Taste Test Method: Single Blind
 
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luke2080

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FYI - The purpose of adding the OO to the starter 5 hours before use is to build up the yeast cells, so they are ready to go. This test could probably be run putting a drop of OO into the fermentor, but at that time the yeast would already start to duplicate (rather than adding the OO to the starter after it has been done, to build them up). Feel free to aerate the initial starter as necessary.

This may very well reveal no results, or very limited results. But to me this is an interesting topic, and one that hasn't been covered to death. After all I've gained over the past couple of years from detailed analysis of co2 use, refractometer adjustments, water chemistry, yeast starters, etc, I figure I'll try to pay it back on this topic. I'm not a scientist or engineer, but I'm used to doing a detailed analysis of variables so I can recommend the right solution to management at my company - or else I get skewered. So I'll put that to some funner use.

Again - please keep opinions to the other thread. But please do provide feedback on the test and anything else that could be recorded.

This is a pretty simple thing to test, and so I hope we get enough of the experienced brewers on this board to join in - if even for 1 or 2 of their batches. If 50 people do 2 tests, splitting each test to at least 2 batches, my math says we'll have at least 200 data points!
 
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luke2080

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Taste Test Results:
Be sure the batches are split into marked glasses, known only to whom is giving the test. (Have your SWMBO set it up for you). Its important it is a blind taste test and rank the beers. This is very subjective, but simply ranks which option you like best.

When performing the Taste Test, the best method is the "blind triangle test". See post 13. If you can do that, please do. Or whether it is single blind, or double blind - post your taste test method with the results. Post 1 has been edited to show this.
 

Denny

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Taste Test Results:
Be sure the batches are split into marked glasses, known only to whom is giving the test. (Have your SWMBO set it up for you). Its important it is a blind taste test and rank the beers. This is very subjective, but simply ranks which option you like best.
It needs to be a blind triangle test. Two of one beer and one of the other. Pick out the one that's different and if it used OO or not. If you misidentify the different beer, the comments about OO are discarded.
 
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luke2080

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It needs to be a blind triangle test. Two of one beer and one of the other. Pick out the one that's different and if it used OO or not. If you misidentify the different beer, the comments about OO are discarded.
Well - that is more complicated if testing 3 or 4 types of aeration methods with the OO.

Another data point that could be gathered though - did this taste like it had OO.

Also - If aeration and OO provide the same result, and same test, tasting the same, there is a 50% chance you'll get the guess wrong about which one is different anyway.
 

Vigo_Carpathian

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The true test would be to try OO without aeration on a 1.090 imperial stout. I do add a drop of OO to my starters (I don't use a stir plate) but I also aerate the wort before pitching, so I'm not sure if it really makes a difference.
 

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Well - that is more complicated if testing 3 or 4 types of aeration methods with the OO.

Another data point that could be gathered though - did this taste like it had OO.

Also - If aeration and OO provide the same result, and same test, tasting the same, there is a 50% chance you'll get the guess wrong about which one is different anyway.
You need to figure out how to do it. I've done enough of these experiments to realize that the triangle test is the only way to go.
 
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luke2080

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The true test would be to try OO without aeration on a 1.090 imperial stout. I do add a drop of OO to my starters (I don't use a stir plate) but I also aerate the wort before pitching, so I'm not sure if it really makes a difference.
The batch that gets the OO needs to have minimal splashing/aeration. At least as minimal as feasible.

So do the starter first. Then 5 or 6 hours before you brew, split the starter, and add OO to one.

Vigo - I agree that the High Gravity beer will show more of an impact. Next time you do this, add this one small step and share the results. :mug:
 
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luke2080

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You need to figure out how to do it. I've done enough of these experiments to realize that the triangle test is the only way to go.
What I'm trying to measure: does it ferment all the way, and does it taste bad/good. The easiest way to quantify the taste test is to rank the beers from the same test. Its a simple NSAT "customer satisfaction" type metric. If we do 100 tests and all the beers ferment to the same rate, and the weight of ranking splits 50/50, its pretty conclusive OO does nothing.

This isn't a test of - can you taste the OO. However, I would think if someone can taste it, it'll get ranked lower than their other test sample.

For what I'm trying to measure, I'll stick with the ranking system.

Added: Did anyone taste OO?: To the list of results. If you have multiple people answer, record all the answers. I'd be interested to see how many people say yes, in batches where none was used.

Denny - that is not exactly what you were looking for, but for what I'd like to test, I'll keep it like that. Thanks for the feedback.
 

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imo without the blind triangle test, the taste results will be incredibly biased.
 

ajdelange

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Beer A and Beer B are put into groups of three half of which have 2 A's and the other half of which have 2 B's. These triplets are randomly assigned to panel members. Neither the server or the panel member knows which group his beer came from nor should he ever have been around the beer before so that, for example, if the OO beer comes out darker he would be unaware of this. Obviously, if it did the samples need to be placed in opaque cups so that the color difference can't be used to pick the odd beer.

The panelist is then told that he must pick the odd beer and that he must decide whether the odd beer is better than the others or not. If he can't decide he must flip a coin. If the olive oil beer is preferred (scores higher) than the other then the probability of getting that scoring by coin flipping (both wrt to choosing the different beer and preferring it) is computed and if that probability is low enough the null hypothesis is rejected and the OO beer declared better.
 
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luke2080

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if the OO beer comes out darker he would be unaware of this. Obviously, if it did the samples need to be placed in opaque cups so that the color difference can't be used to pick the odd beer.
Not sure how in the world one would come out darker.

So we'll add that. I'm doing my taste tests as Single Blind. If you can do Double Blind or Triple Blind, do so. Then with the taste results, identify which taste test method you used.

If we have enough results, I can show the results by taste test type.

I think its more important to pick out whether you can taste OO. Some tests will be OO vs No Aeration. Others OO vs O2 tank. When they both come out with the same results, not sure flipping a coin of which tastes better shows anything - when they both taste equally good, bad, or average.

Made edits to the initial instructions to include "taste test method".
 

ajdelange

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I'm not suggesting that one beer will be darker or lighter but of course one exposed to oxygen probably will be darker. What I am trying to point out is that one must control for such things. Failure to do so likely impairs the statistical significance of any test result just as failure to do a double blind triangle test would.
 

Denny

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I'm not suggesting that one beer will be darker or lighter but of course one exposed to oxygen probably will be darker. What I am trying to point out is that one must control for such things. Failure to do so likely impairs the statistical significance of any test result just as failure to do a double blind triangle test would.
Hear, hear! I've done enough experiments wrong to have discovered how important it is to design and control the experiment in order for the result to be more vaild than an opinion.
 

pjj2ba

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The triangle test in not complicated to run. I plan to do some triangle tests this weekend - with salt additions to a beer(s). I'll add the same amount of salt to two tasting glasses and none to a third, and then ask my panelist: A, can you pick the odd man out, B, do you like it better. This is a very simple way to set up a tasting, and it really helps to validate the findings. If the taster cannot correctly identify the odd beer out, that means there is no difference in whatever is tasted. If there can correctly identify the odd beer, then I will ask which do they prefer. If they don't pass A test, then there is no point in asking B.

If you are comparing your OO beer with a conventionally aerated beer via the triangle test method, if the tasters cannot correctly detect which of the three is different from the other two, then you know the OO method had no affect on the final product. If they can correctly pick it out, then you can ask which they prefer. To be even more confident, you can do the test again with the same person. If they can pick the odd beer again, you can be fairly sure the difference is real.

I want to find out what the threshold for tasting the effect of added salts is. 20 ppm? 60ppm? Is it the same for Cl- and SO4-. Once we get thresholds for both, then on to the blends with different ratios
 

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I think its more important to pick out whether you can taste OO. Some tests will be OO vs No Aeration. Others OO vs O2 tank. When they both come out with the same results, not sure flipping a coin of which tastes better shows anything - when they both taste equally good, bad, or average.

Made edits to the initial instructions to include "taste test method".
You won't taste the OO. To make that the goal, and not doing a triangle blind test would make the experiment relatively meaningless.

The goal should be to see if OO is indeed a good sub for aeration. In order to see if that happens, a triangle test should be done. Otherwise, the experiment would be invalid.
 

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I'm enjoying watching this thread swing around to same points made in the previous thread.
Yes, and I am sorry about that! I don't think any of us mean to derail the thread about the experiment. There are some scientists on here, though, making suggestions to make the experiment meaningful, and I think that they made some valid points that should be taken into consideration. This is a lot of work, and a lot of data, and so it would make sense to have a proper format before anyone does this.
 

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When they both come out with the same results, not sure flipping a coin of which tastes better shows anything - when they both taste equally good, bad, or average.
Missed this earlier. It's at the heart of hypothesis testing. You can't prove a hypothesis such as: Beer made with olive oil tastes of olive oil. You can only show that the null hypothesis: Beer made with olive oil doesn't taste any different from beer made with conventional aeration is an unlikely explanation for the data you collect. If the null hypothesis is true you might as well flip a coin because tasting isn't going to tell you anything. What you are really testing is how often the panelists have to flip a coin or choose the different beer by any other random means such as picking the cup nearest to them or the one they tasted first.
 

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Yes, and I am sorry about that! I don't think any of us mean to derail the thread about the experiment. There are some scientists on here, though, making suggestions to make the experiment meaningful, and I think that they made some valid points that should be taken into consideration. This is a lot of work, and a lot of data, and so it would make sense to have a proper format before anyone does this.
Don't be sorry, it is a good point.
 

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You won't taste the OO. To make that the goal, and not doing a triangle blind test would make the experiment relatively meaningless.

The goal should be to see if OO is indeed a good sub for aeration. In order to see if that happens, a triangle test should be done. Otherwise, the experiment would be invalid.
The field of "Did anyone taste OO" should not be there. Or, if it is left in, then the rest of the results for said post should be ignored and disqualified from this thread.

Anyone who puts that much OO in their beer didn't read/understand the thesis.
 

ajdelange

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Adding olive oil does have flavor effects - the MBAA paper indicate that the beer becomes more estery - and it would be interesting to check on that. One of the nice features of a triangle test is that you can have panelists, after they have picked the odd beer, answer a series of other questions such as
Is the odd beer more or less sweet than the others?
Does the odd beer taste more like olive oil than the others?
Is the odd beer more bitter than the others?
Does the odd beer taste fruitier than the others?
Does the odd beer have more diacetyl than the others?
etc.

By doing this you can determine whether the OO beers are statistically significantly different tasting and if so along which flavor axis (including an olive oil taste axis).
 

Wynne-R

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I think AJ is playing devil’s advocate. Maybe it’s a sneaky null hypothesis thing.

Two drops is a little less than .1 ml. In 19L of beer, that’s half a part per million. Plus it’s added to the starter and metabolized by the yeast. Any remaining olive oil has to be way below the taste threshold.

I would think asking about olive oil would bias the survey.
 

broadbill

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Two drops is a little less than .1 ml. In 19L of beer, that’s half a part per million. Plus it’s added to the starter and metabolized by the yeast.
has it be directly shown that the yeast metabolizes it? Or is this conjecture?

I would think asking about olive oil would bias the survey.
It only biases the second half of the survey (asking how it is different); It would not put bias in the first half where the taster is asked if they are different in the first place.
 

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has it be directly shown that the yeast metabolizes it? Or is this conjecture?
In theory, yes the yeast can metabolize it. My question is do they have access to it? Does the oil disperse well enough into the wort so the yeast have access to it? If it just floats on top, it won't be taken up very rapidly by the yeast.

I did a few experimental beers with sauteing hops pellets in oil (for rapid isomerization) and then adding the cooked hops and oil to the mash (I found out that much of the bitterness went out into the oil - talk about bitter oil!). To deal with the oil I added lecithin to emulsify the oil (it did disappear from the surface). I don't know how much of the oil got trapped in the mash tun, but there were no head retention issues in the final product - SIX tablespoons of oil went into the mash.

This was before the OO experiment so I didn't pay attention to how the fermentation proceeded
 

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In the thesis, they used between 1 mg olive oil/67 million cells and 1 mg olive oil/25 billion cells.

Is 1 or 2 drops in a 5 gallon batch comparable to these numbers?
 

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Adding olive oil does have flavor effects - the MBAA paper indicate that the beer becomes more estery - and it would be interesting to check on that. One of the nice features of a triangle test is that you can have panelists, after they have picked the odd beer, answer a series of other questions such as
Is the odd beer more or less sweet than the others?
Does the odd beer taste more like olive oil than the others?
Is the odd beer more bitter than the others?
Does the odd beer taste fruitier than the others?
Does the odd beer have more diacetyl than the others?
etc.

By doing this you can determine whether the OO beers are statistically significantly different tasting and if so along which flavor axis (including an olive oil taste axis).
Yes, there are flavors that can be generated by the addition of OO. However, these flavors are not Olive Oil flavors. As you said, there are esters produced from adding OO. However, these esters are created by the yeast from the difference in environment/nutrients (vs. aeration), not from direct OO flavors.
 

ajdelange

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I am not saying that you should (or shouldn't) look for an olive oil flavor. I'm just trying to point out that you can be quite flexible in what you can determine from a properly conducted test. The basic test has a null hypothesis that reads something like "Use of olive oil as opposed to normal oxygenation has no effect on beer." If you find, on the basis of test panel data, that the null hypothesis should be rejected it is natural to want to know why. That's what the secondary question(s) are for.
 

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I realize this is somewhat OT for the thread, but I've been experimenting with OO as a supplement in the media I use to prepare yeast stocks for freezing. I maintain a large-ish yeast bank for my local brewclub (details in my blog, if anyone wants the details), and have been trying to find ways to maximize viability of yeast post-freezing. My normal growth medium is DME @ 1.040 + a zinc supplement at the manufacturers recommended dose. To this I added 0.1ml/L OO. Yeast were grown on a shaker to maximize oxygenation. My rational was essentially to allow the yeast to maximize their production of glycogen/sterols by minimizing their need to synthesize unsaturated fatty acids.

I did a side-by-side, growing wyeast 1056 normally or with OO, freezing at -80C in 1.040 wort + 20% glycerol, and then thawing a sample and using trypan blue to test for post-freezing viability, and I did a post-freezing growth test. The difference in viability was negligible - 68% (normal) vs. 71% (OO), but the OO yeast did come out of lag phase a little faster (budding yeast were observed after 3.5hrs (OO) vs. 5hrs (normal)). This may represent larger glycogen stores or less freezing stress.

It would be interesting to see the effect of this on a starter; in theory you may get larger yeast numbers or happier yeast. I'm not sure I'd want to add OO directly to the fermenter, just because of the potential impact on head retention.

Bryan
 
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luke2080

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In theory, yes the yeast can metabolize it. My question is do they have access to it? Does the oil disperse well enough into the wort so the yeast have access to it? If it just floats on top, it won't be taken up very rapidly by the yeast.
Taste testing aside - This is the point of capturing the FG results. Without proper aeration it is tougher for the yeast to fully attenuate to the degree planned. So capturing the FG of the OO version and different versions of other aeration methods is the most meaningful testing of this, IMO. Without sending every sample for a full lab diagnostic.

I plan to run my taste tests using the triangle method. Should be easy enough - pick out the odd beer, than compare the odd beer with the other.

If the use picks the odd beer incorrectly - are all of their taste test results afterwards (which is bettter, was their off flavors, fruitier, more bitter, etc) then null and void?

I'll tweak the initial instructions to account for this. Makes sense to do that.

I do hope those of you providing feedback run this test a time or two this year as well!

I should have results from my first batch following the tighter control in 3-4 weeks. And will do this with every batch this year.
 

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Could this be done in a more objective manner? Something like: make 2 yeast starters, one only with OO, the other on a stir bar. Then do a cell count of both starters. Dump in a measured amount of something toxic to yeast, I'm thinking vodka. Do another cell count. Theoretically, if the OO does as good as traditional aeration, they should have similar amounts of dead cells.
 

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Could this be done in a more objective manner? Something like: make 2 yeast starters, one only with OO, the other on a stir bar. Then do a cell count of both starters. Dump in a measured amount of something toxic to yeast, I'm thinking vodka. Do another cell count. Theoretically, if the OO does as good as traditional aeration, they should have similar amounts of dead cells.
why is killing the cell necessary? Shouldn't the first measurement be adequate to prove your hypothesis?

Also, killing the cells may be another step at which OO may have an effect; if it does have an effect it might be difficult to interpret the results of OO's cumulative effects.
 

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If the use picks the odd beer incorrectly - are all of their taste test results afterwards (which is bettter, was their off flavors, fruitier, more bitter, etc) then null and void?
If a panelist can't tell whether one beer is different from another how can he tell whether it is sweeter or fruitier than another?

If you are going to do a triangle test you will need to be able to compute the confidence levels associated with your observations. There are tables or you can use a spreadsheet such as this one:
http://wetnewf.org/pdfs/Brewing_articles/Triangle.xls
 

broadbill

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Taste testing aside - This is the point of capturing the FG results. Without proper aeration it is tougher for the yeast to fully attenuate to the degree planned. So capturing the FG of the OO version and different versions of other aeration methods is the most meaningful testing of this, IMO. Without sending every sample for a full lab diagnostic.
The effect of OO on FG vs. normal aeration is already known (no difference). OO appeared to slow the kinetics of fermentation however-OO took longer to reach FG.

What exactly are you trying to demonstrate, that hasn't already been done? Just that this also happens at the home-brew level? Is there any reason to believe that it doesn't?
 

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why is killing the cell necessary? Shouldn't the first measurement be adequate to prove your hypothesis?

Also, killing the cells may be another step at which OO may have an effect; if it does have an effect it might be difficult to interpret the results of OO's cumulative effects.
Yeah, just counting the cells might do it. I feel like introducing a toxic element helps us determine if the cells are as strong as with traditional aeration is another useful data point.

It seems to me that this test should definitely be done before the full batch taste tests. If you already have a microscope and cell counting thing, it could be done for a few bucks and in 2 or 3 days.
 

broadbill

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Yeah, just counting the cells might do it. I feel like introducing a toxic element helps us determine if the cells are as strong as with traditional aeration is another useful data point.
What you need to do is test a range of ethanol concentrations.

The problem with using a single concentration that kills 100% of the control cells is that it will be pretty darn toxic to the OO yeast, even if the hypothesis is correct that OO makes yeast more resistant. It is tough to see a significant difference in this experiment. The same goes for a too low concentration of ethanol.

The standard measurement for these studies is LD50, the dose of toxin that causes 50% lethality. Then compare LD50 of control versus OO yeast. Differences in that value tell you if OO has the effect of making yeast more resistant to ethanol.

If you already have a microscope and cell counting thing, it could be done for a few bucks and in 2 or 3 days.
I disagree, based on my explanation above. It is a much more detailed experiment to do it correctly.
 
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