Olive Oil - New Thread - No Recent Posts

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I tried using olive oil as an experiment after a suggestion by another brewer with interesting results so far.
Last night I made two starters from Wyeast 1084 Irish Ale, on dark dry malt to SG1040, ready for the two porters I am brewing today.

I poured 4 liters of boiled wort, with 2grams of nutrient into a 5 liter demijohn in water bath to cool to 20degC, added yeast from activated pack, shook like crazy, poured 2 liters into 5 liter demijohn with smidge (new scientific measurement unit) of olive oil for sterols.

After 14 hours, the one with olive oil is different from the other for sure.

The olive oil starter is producing less gas, has less sediment and the froth on top of the wort is made of big bubbles not fine meringue like the other.

Olive oil absolutely makes a difference; I dont know what but there you go.

I took photos but they don't show the obvious variation.



Anybody out there have a take on the differences?

 

[Wolfy]

I poured 4 liters of boiled wort, with 2grams of nutrient into a 5 liter demijohn in water bath to cool to 20degC, added yeast from activated pack, shook like crazy, poured 2 liters into 5 liter demijohn with smidge (new scientific measurement unit) of olive oil for sterols.
...
The olive oil starter is producing less gas, has less sediment and the froth on top of the wort is made of big bubbles not fine meringue like the other.
...
Anybody out there have a take on the differences?

I thought the olive oil 'thing' came about because someone did an experiment and suggested it could be used as an alternate to aerating wort?
However, it seems that you've shaken/aerated the wort and then split it into two batches, one with some oilve oil (from memory the experiment suggested the amount you need for home brewing is less than a pin-head, so how much is a smidge?)

However, less gas, less sediment, and bigger 'bubbles' sounds like a less active ferment to me.

 

[MHB]

If by "smidge" you mean any portion visible to the naked eye, then you have probably used about 100 times too much oil and are just seeing surface tension effects on the bubbles.

I'm far from convinced that olive oil is a complete answer. But any way here is the original document View attachment 40477you can do your own conclusion drawing.

MHB

 

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Wolfy,

it would appear that way but it may be the yeast is taking longer in it's adaptation phase. Perhaps getting healthier before setting off on a marathon sugar eating journey?

Mark from MHB sent me a great article on the use of olive oil. Mark is probably right (as always) in that changes in surface tension likely explain the bubble / foam difference.

The article suggests there is room for more experimentation with more olive oil and or more aeration.

My experiment was far from scientific, I just wanted to see if there would be a noticeable difference in fermentation vigor or final gravity. I now wish I had the forethought to split a single batch of the same beer as there are far greater impacts than just ferment vigor. While I carried this experiment out on two porters they are two different recipes and I wont be able to see if there is a difference in flavor stability and increased ester production suggested in the article posted by Mark.

Mark,

As always, thank for your insight and help.

By the way, I will need another glass carboy to run the olive oil test on a single batch, do you have one by chance? I will pick it up with my Brain Spasm grain bill.



TeeDee