Aeration / Olive Oil / Efficiency

[SpanishCastleAle]

I can't remember where I read it but from what I recall, your results are similar to others; i.e. the EVOO samples having a longer lag but then fermenting faster once it gets going.

 

[lamarguy]

I can't remember where I read it but from what I recall, your results are similar to others; i.e. the EVOO samples having a longer lag but then fermenting faster once it gets going.

Actually, they found an increased fermentation time and increased ester production from olive oil.

 

[weirdboy]

Actually, they found an increased fermentation time and increased ester production from olive oil.

There's a section of that paper entitled "Analytical Analysis".

 

[lamarguy]

There's a section of that paper entitled "Analytical Analysis".

Correct, here are some quotes:

The olive oil test fermentation was 20% longer than the average aerated fermentation during that time period but it did attenuate completely. Both had good yeast viability.

The ester profile for the test in Figure 1 was higher than that of the control but not out of the breweries specifications for the brand.

Despite the increase in esters, the taste panel found no significant difference in the flavor of the non-aerated olive oil beer (shown below) despite the increase in acetaldehyde, ethyl acetate, isoamyl acetate, and ethyl hexanoate.

View attachment 12864

 

[weirdboy]

Despite the increase in esters, the taste panel found no significant difference in the flavor of the non-aerated olive oil beer (shown below) despite the increase in acetaldehyde, ethyl acetate, isoamyl acetate, and ethyl hexanoate.

I read the whole paper. Here are some other quotes:

The results of the sensory panel are given in Figure 7. Again the test was rated higher in isoamyl acetate and sweetness but the differences were not statistically significant. Some esters such as ethyl hexanoate and ethyl acetate were actually perceived as being higher in the control. Based on the results shown in Figure 7, the goal of this study, which was to achieve a flavor match without aerating the wort, was achieved in this third test.

After three weeks warm storage the olive oil test was significantly less oxidized than the control. It was also perceived by the panel as retaining more of the fresh beer attributes such as ester and hop flavors (Figure 11). Overall the olive oil test was preferred to the control.

Now, these last two quotes were from the final two tests performed, where the olive oil had been increased by 100% over test two, and 33% higher between tests one and two.

I also thought it was interesting that the GC results showed a lack of DMS in test batches one and two, and lower DMS levels in tests three and four. But, the sensory panel still placed the DMS levels near the control batches in each case.

Overall this seems like a good reason to try using olive oil on my next batch. It seems a rate of 1 mg/25 billion cells is what I should aim for, so about 9mg of olive oil I suppose for my next batch. I plan to hydrate the yeast and mix the olive oil into the yeast slurry, rather than into the wort.

 

[weremichael]

I have tried using a paper clip tip, dipped in olive oil in several of my beers. I didn't notice any off flavors or oily taste. As far as duration of fermentation or attenuation, I can only be anecdotal so I'll leave that out. I've talked to a brewer at New Belgium and they quit they're experiment with olive oil over a year ago.

 

[Bsquared]

Okay It looks like things are moving along well, and the olive oil batches are taking the lead.

1) 1.031
2) 1.031
3) 1.031
4) 1.028
5) 1.028
6) 1.028

Because I'm using a refractometer, I don't get to taste much, but I can't discern much of a taste difference between the batches.

 

[craigd]

Just wanted to say kudos on performing this experiment! This is the kind of stuff that makes this the best forum out there. Can't wait for the results!

 

[Bsquared]

I guess I need to do some work with getting the brix to gravity conversion down. I was a little surprised the past few readings, and was thinking I was a little high. I just took two Specific gravity tests with my hydrometer so I got a whole 100ml taste!

the 1gallon aerated sample with no olive oil is at 1.022 @ 60ºF

the 1gallon non-aerated sample with olive oil is at 1.014 @ 60ºF

My 6 gallon batch is at 1.026 @ 60ºF

Flavor wise at this stage, I could only discern a difference in attenuation, the three beers where vary similar in taste, and with the ester profile it was hard to pick up a difference beyond that of sweetness.

Looks like I might try a little Olive oil in my next batch.

 

[Beernik]

Once you start fermenting, the standard chart for S.G to Brix doesn't work. The ABV calculation for a refractometer is:

(O.Plato - F.Plato)*0.42/0.8

I think I pulled that out of one of my Palmer books. From that you can back calculate the specific gravity.

 

[weirdboy]

Any updates on this?

 

[weirdboy]

*TAP* *TAP* *TAP*


Is this thing on?

 

[Bsquared]

I'm going to check things tonight, I was out of town this weekend.

I think I will let them sit in the primary for about 10 more days before transferring to the keg/bottles. I'm having a group over October 24th and I will probably set up a blind tasting at that time with a bigger group.

If any one in the area wants to swing by for it in October, PM me and I shoot you the specifics. I should be having four other beers on tap(ESB, Pliny, Pumpkin spice ale, and some thing else?) and I always like feedback from brewers.

 

[Bsquared]

So I was out of town so I missed leveling off, but there seems to be a pitching rate issue that has arisen from this experiment, so I don't think any Taste comparison will really be valid. It might be a good Idea for me to repeat this experiment with a few changes to really determine if there is no noticieable flavor change by using Olive oil. From reading the papers posted from this thread I will pre-conclude that the differences in final flavor would be not be precipitable, but it would be a simple experiment.

To todays data:

All batches have finished at FG 1.012 @ 60ºF

the 6 gallon batch, which was produced as I normally do (Stirred Starter with calculated yeast count determined by Mr.Malty calculator pitched in to Aerated Wort) was probably pitched with twice the yeast that all the other batches were.

I took samples from all batches today and the 6 gallon batch has noticeably thicker haze that is expected from a wit. where as the 5 other gallons that where pitched with 1/5 of a white labs vial, were significantly clearer. indicating to me that the yeast did not reach an optimal population.

Taste wise, the 6 gallon batch had a good fruity ester profile, with some spice and hot alcohol, all together balanced and complex with the slight bitterness of the hops and spice from the nutmeg and coriander.

the 5 1 gallon batches all lacked the haze one would expect form a wit. as well many of the ester flavors that come along from having these yeast in suspension where lacking. This led to a mono tonal ester profile, were only the hot spice ester note came through. The lack of fruit was vary evident in all the 5 beers, and a difference could not be attributed to Olive oil.


I plan on writing this up as I do a scientific paper in the near future, but for now I think the take home message is that Olive oil appears to aid in attenuation in non-aerated wort. I am some what conflicted about these results, because I clearly saw that the Olive oil batches increased the rate of fermentation, but it also demonstrated to me that one vial of WL-400, is not the proper amount to pitch. Even though the non aerated/no olive oil batch finished probably at the same time as the 6 gallon batch, there was a clear difference to the two batches.


I am curious to hear the results from the BYO/Basic brewing radio pitching rate experiment.

 

[Bsquared]

The only criticism I have of your set up is that I wish you also had 1 gallon of the traditional stuff, instead of 6 gallons. It's probably minor, but 6 gallons of wort doesn't behave exactly as 1 gallon does. Otherwise, I LOVE this idea! Thanks so much for doing this for all of us.

I should have listened...
So Yooperbrew is probably right on about this, that the yeast in the big batch are not going to behave like the yest in the one gallon batches.

Any one else listen to the brew strong fermentation vessel show? I did and I thought it was interesting that Jamil mentioned that Vinny from Russian River had to experiment with his fermentation vessels with his Belgian style ales to get the proper ester profile he was looking for. I was thinking that this might be the issue with my flavor differences?

So now the question is, did this difference just affect the flavor of the beers? or did it also attribute to the difference in attenuation rate? I'm not sure but I think that the attenuation rates are real due to the addition of Olive oil.

For this experiment I will say that we can only compare the 5 One gallon batches, and that all can be determined is there is a difference in attenuation rates, and any difference in flavor was negligible.

Though the difference in batch volume and flavor was noticeable, but could be due to pitching rates, or batch volume? so I guess it will be for another experiment.

This is the problem with experiments, once you factor in all the controls and sample sizes, you go from having to brew a 10 gallon batch to having to brew 30 gallons...

It would be neat if we here at this site could set up a collaborative to do experiments, where as a question could be asked, and a group could determine and experimental recipe and protocol that any one could decide to precipitate in, collect data, and share the results.

 

[axlrose16]

I posted quite early in this thread that there has already been a dissertation written on this technique and you should read it as opposed to wasting more time on experiments. The method works. Quite effectively, I might add.

 

[Bsquared]

I posted quite early in this thread that there has already been a dissertation written on this technique and you should read it as opposed to wasting more time on experiments. The method works. Quite effectively, I might add.

Yes , you did, and thanks for posting that, it is how I determined the amount of Olive oil to be used, and I do agree from what I saw and what I read, it worked well. I just like to do experiments

I think now I'm interested in the difference between the 6 gallon batch and the 1 gallon batches.

But I probably be adding a little olive oil next time I pitch a new vial. as for right now though I'm re-pitching.

 

[bkov]

how about just dipping a hop pellet in alittle olive oil then dropping that pellet into the carboy when you pitch the yeast

 

[Bsquared]

how about just dipping a hop pellet in alittle olive oil then dropping that pellet into the carboy when you pitch the yeast

You need to add the oil to the yeast directly before you pitch, so they will have time to absorb the sterols and unsaturated fatty acids. If you just added them to the carboy I doubt the yeast would be able to utilize them. Oil does not dissolve in water so only the yeast in contact with the hop pellet that was soaked, would have access to the oil.

 

[The Pol]

What if you dropped a soaked hop pellet into your yeast starter?

 

[bkov]

the oil would get just as much into the wort from a hop pellet then it would from a metal skewer dipped in

 

[z987k]

I'm not sure but I think that the attenuation rates are real due to the addition of Olive oil.

I'm trying to figure out how you came to this conclusion. All the beers finished at 1.012 including the no olive oil no aeration. So to me this means the olive oil didn't produce any better attenuation than doing nothing.

 

[Bsquared]

I'm trying to figure out how you came to this conclusion. All the beers finished at 1.012 including the no olive oil no aeration. So to me this means the olive oil didn't produce any better attenuation than doing nothing.

Sorry I might not have been clear. Buy attenuation rate, I was referring to how fast the beer fermented. In the batches that got olive oil they where at 1.012 at around day 5-6 where the other batches reached 1.012 around day 7-8.

You are right though that the apparent attenuation was the same for all beers at 75.9%

 

[Haputanlas]

Sorry I might not have been clear. Buy attenuation rate, I was referring to how fast the beer fermented. In the batches that got olive oil they where at 1.012 at around day 5-6 where the other batches reached 1.012 around day 7-8.

You are right though that the apparent attenuation was the same for all beers at 75.9%

Bsquared,

Have you pursued this any further? I'm trying to assess how many people actually do this on a regular basis.

One of my brew buddies has done this for a long time, but I'm still a little bit skeptical. I might try one of my own tests to see what I can come up with.

One of the concerns I see with the test above is the amount of oxygen that was absorbed from transferring the wort from the brew pot to the fermenter. Might be interesting to transfer into a fermenter that already has a nice C02 blanket to confirm that there is no oxygen at all for the yeast to work with.

 

[crushingblackdoom]

I've done it. It works. It's weird, for sure. I burned a safety pin white hot, wiped it clean with alcohol, dipped it in some EVOO, shook it off, dipped just the tip of the pin into my wort, and made a couple of good beers. Just sayin'.

 

[Denny]

Did you have a control to compare it to? I have to admit I'm skeptical unless someone splits a batch and tries it both ways. The only test I'm aware of that did that found that the OO batch tasted stale sooner then the non OO batch.

 

[crushingblackdoom]

Did you have a control to compare it to? I have to admit I'm skeptical unless someone splits a batch and tries it both ways. The only test I'm aware of that did that found that the OO batch tasted stale sooner then the non OO batch.

I have not done a side by side. Sometimes I use oo, mostly I just use my stick blender to foam up the wort. If anything, I think I'm getting over-attenuation. Maybe too much oxygen...

 

[Denny]

Or maybe a miscalibrated thermometer. More likely IMO.

 

[ak-71]

Would be interesting to see a 1 gal non-aerated/no-starter version to see if any of that needed with this pitch rates