Germey
Well-Known Member
I just listened to a BrewCrazy podcast talking about a recent paper published by an employee at New Belgium.
Here's an abstract...
Olive Oil Addition to Yeast as an Alternative to Wort Aeration
To extend the flavor stability of their beers, many breweries are researching ways of reducing oxygen ingress throughout the brewing process. However, the practice of aerating the wort prior to fermentation is almost universal in the brewing industry because oxygen is necessary for yeast health and growth. Recent studies have shown that alternative methods to traditional wort aeration such as aeration of the yeast prior to pitching or the addition of the unsaturated fatty acid linoleic acid can yield fermentation characteristics similar to wort aeration. It has also been shown that using these alternative methods instead of aerating the wort can reduce oxidation potential. This paper reports the findings of a series of full-scale production tests that were conducted in an operating brewery to evaluate the effects of another type of yeast treatment. By mixing olive oil into the yeast, during storage, instead of aerating the wort, fermentations can be achieved with only minor increase in fermentation time. The beers produced from these fermentations were comparable in flavor and foam retention to beers produced by traditional wort aeration. The ester profile of the beers produced using olive oil addition was significantly higher than the controls and the flavor stability of these beers was significantly improved.
Presentation PresentationBibliography:
Grady Hull graduated from Colorado State University in 1994 with a BS in Food Science and Technology. After an intership with Coors Brewing Company he worked as a brewer for CooperSmith's and Fleetside brewpubs. In 1996 he began working at New Belgium Brewing Company where he is currently the Assistant Brewmaster. While working at New Belgium he recieved his MSc in Brewing and Distilling from Heriot-Watt University.
Is presentation an:
OriginalWork
Work done at:
New Belgium Brewing Company
The difficulty is that they only use a very small amount at full production scale. Here is a quote from someone at New Belgium
"The olive oil thing was the result of some research done first at the University of Leuven in Belgium, and then some full scale testing we did here at New Belgium.
"The basic concept is that since yeast uses an oxygen atom to pull a hydrogen away from an 18 carbon chain unsaturated fatty acid to make a monounsaturated fatty acid chain to help it grow, you could simply provide an 18 carbon monounsaturated fatty acid and it would be able to use that. This works well in practice, we made a little over 1 million bottles with beer where the yeast had had olive oil added.
"The main thing to remember is that since you're working on a molecular level, and the olive oil has a high concentration of that molecule, the amount you actually need is pretty small. Additionally, you want to use a very small amount to avoid any detrimental effects that the oil would have on the beer's head retention.
"For the volume of wort we normally ferment, we would pitch about 4500L of yeast, and to that we would add around 300mL of olive oil. To translate that into a 5 gallon size, you would need to measure about 0.0000833mL of olive oil. For any practical purpose, that is much too small an amount to accurately measure out. You could fudge and just add the tiniest imaginable drop to the yeast you have, but you'd be over-dosing the oil by thousands of times the required amount, and run the risk of having zero foam retention. Not a good compromise in my opinion.
"The bigger picture is this: for us, we did this as a way to avoid potential for oxygen free radicals to contribute to staling off flavors, and hopefully could count on getting an extra 2-3 weeks of shelf life time in the finished product."
So a couple of the guys on BrewCrazy tried it on the 5gal scale and had good results by putting one drop in a quart of water, boiling it, then adding between one drop and a teaspoon to the wort.
Anyone else heard more about this? Anyone want to give it a try?
Here's an abstract...
Olive Oil Addition to Yeast as an Alternative to Wort Aeration
To extend the flavor stability of their beers, many breweries are researching ways of reducing oxygen ingress throughout the brewing process. However, the practice of aerating the wort prior to fermentation is almost universal in the brewing industry because oxygen is necessary for yeast health and growth. Recent studies have shown that alternative methods to traditional wort aeration such as aeration of the yeast prior to pitching or the addition of the unsaturated fatty acid linoleic acid can yield fermentation characteristics similar to wort aeration. It has also been shown that using these alternative methods instead of aerating the wort can reduce oxidation potential. This paper reports the findings of a series of full-scale production tests that were conducted in an operating brewery to evaluate the effects of another type of yeast treatment. By mixing olive oil into the yeast, during storage, instead of aerating the wort, fermentations can be achieved with only minor increase in fermentation time. The beers produced from these fermentations were comparable in flavor and foam retention to beers produced by traditional wort aeration. The ester profile of the beers produced using olive oil addition was significantly higher than the controls and the flavor stability of these beers was significantly improved.
Presentation PresentationBibliography:
Grady Hull graduated from Colorado State University in 1994 with a BS in Food Science and Technology. After an intership with Coors Brewing Company he worked as a brewer for CooperSmith's and Fleetside brewpubs. In 1996 he began working at New Belgium Brewing Company where he is currently the Assistant Brewmaster. While working at New Belgium he recieved his MSc in Brewing and Distilling from Heriot-Watt University.
Is presentation an:
OriginalWork
Work done at:
New Belgium Brewing Company
The difficulty is that they only use a very small amount at full production scale. Here is a quote from someone at New Belgium
"The olive oil thing was the result of some research done first at the University of Leuven in Belgium, and then some full scale testing we did here at New Belgium.
"The basic concept is that since yeast uses an oxygen atom to pull a hydrogen away from an 18 carbon chain unsaturated fatty acid to make a monounsaturated fatty acid chain to help it grow, you could simply provide an 18 carbon monounsaturated fatty acid and it would be able to use that. This works well in practice, we made a little over 1 million bottles with beer where the yeast had had olive oil added.
"The main thing to remember is that since you're working on a molecular level, and the olive oil has a high concentration of that molecule, the amount you actually need is pretty small. Additionally, you want to use a very small amount to avoid any detrimental effects that the oil would have on the beer's head retention.
"For the volume of wort we normally ferment, we would pitch about 4500L of yeast, and to that we would add around 300mL of olive oil. To translate that into a 5 gallon size, you would need to measure about 0.0000833mL of olive oil. For any practical purpose, that is much too small an amount to accurately measure out. You could fudge and just add the tiniest imaginable drop to the yeast you have, but you'd be over-dosing the oil by thousands of times the required amount, and run the risk of having zero foam retention. Not a good compromise in my opinion.
"The bigger picture is this: for us, we did this as a way to avoid potential for oxygen free radicals to contribute to staling off flavors, and hopefully could count on getting an extra 2-3 weeks of shelf life time in the finished product."
So a couple of the guys on BrewCrazy tried it on the 5gal scale and had good results by putting one drop in a quart of water, boiling it, then adding between one drop and a teaspoon to the wort.
Anyone else heard more about this? Anyone want to give it a try?
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