Aaron Beers
Well-Known Member
I've been thinking about techniques for peanut flavored beers. Sharing some thoughts, welcome any feedback.
Most peanut beers/talk of peanut beers involves peanut powder, which is the remaining peanut product after pressing roasted peanuts to extract the peanut oil. It seems to me that this is not an ideal ingredient for adding peanut aroma to a beer.
Roasted peanut oil, however, has an intense aroma of roasted peanuts. Further, molecules that provide aroma tend to be highly soluble in fat, so I'd venture to say that a significant portion of the aroma in whole roasted peanuts is extracted alongside the fat during pressing.
So whats left behind after this process? A little checking on peanut flour nutrition facts shows composition (by weight):
50-55% protein
13-20% fat
11-14% fiber
7-12% complex carbohydrates
6-8% simple sugars
Peanuts are approximately 50% fat by weight, so if the product remaining after pressing is ~15% fat, that means ~82% of the fat has been removed, which is a large portion of the material with highest concentration of aroma.
If you add this powder to beer, most of the simple sugars and some of the starches will dissolve into it. Some of the fat will likely separate out of those solids, largely depending upon how it's mixed into the beer. Some fiber is water soluble so you might get some of that. Proteins break down to amino acids in the presence of acid, so you might get some of that dissolving into the beer. All of those things can be desirable in the beer to some extent (excluding the fat) as they would lend body. There will certainly be a line where you have too much "stuff" dissolved into the beer, where it has too much body and you don't want to drink it.
Presumably, the peanut powder would also absorb liquid when added to the beer, reducing the ultimate yield, and accelerating the point at which the remaining beer would have too much stuff dissolved in it. I presume the amount of beer loss due to absorption by the peanut powder would be non-trivial by the time you've added enough peanut butter powder to get a sufficiently intense peanut aroma in the beer.
Flip the script. The roasted peanut oil has a significantly higher concentration of aroma molecules than the powder. Extracting those into a water based solution would allow you to add peanut aroma, and just peanut aroma, to beer.
In the past, I've extracted aroma from fats by mixing them with a strong alcohol solution, mixing, letting the mixture separate, solidifying the fat and the draining off the alcohol solution. This would seemingly be a non-starter for flavoring beer. By the time you've added enough of the "seasoned" alcohol to the beer, I think you would have added enough alcohol to push this well outside the category of beer.
In speaking with a chemist, I was told that the main aroma molecules in peanuts are "not particularly hydrophobic." If so, simple agitation of peanut oil and water (as in, on a stir plate), perhaps with a splash of alcohol added, should be sufficient to extract a noticeable amount of peanut aroma. From there, instead of water, it may be possible to use wort/beer to extract aroma from the peanut oil.
Presuming the extraction works, the question becomes, when should the extraction take place? The reasonable options I can think of are:
1. In the water used to mash
2. In the post boil wort
3. Post fermentation
By extracting peanut aroma to the water used for the mash, you can "season" the entirety of the water without any loss of aroma back to the oil. Which is to say, if you have a bunch of malt aroma in the wort and mix it with the peanut oil, some of the aroma from the peanut oil will make it's way into the wort and some of the aroma of the wart will make it's way into the peanut oil. By using plain water before mashing, you only extract aroma from the peanut oil. The downside though is those aromas will be put through the entire brewing process, during which time you will likely lose a non-trivial amount of intensity.
By extracting peanut aroma to the post boil wort, you avoid the high heat processes that are most likely to drive off aroma molecules. However, you still expose the peanut aroma molecules to the fermentation process. As is noted with hops, fermentation tends to expel some of the aroma. The amount of loss would obvious be less than if the aroma molecules were present for the entire beer brewing process. In addition, extracting to wort will likely emulsify at least a small amount of oil, which will likely preclude any head formation while pouring the finished beer.
By extracting peanut aroma to the post fermentation beer, you avoid all the processes that would lower the intensity of that aroma. However, it becomes more of a challenge to extract the aroma into the finished beer without also incorporating oxygen. It may be possible to perform some kind of pressurized transfer, then encourage extraction of aroma by shaking, then somehow siphon off just the beer, but that also sounds quite difficult.
Of these, I think I'll be trying the post boil, pre fermentation extraction into wort, alongside peanut butter powder on the top of the mash. I'm also thinking of making a bigger, fuller bodied beer with the intention of some dilution post fermentation using water into which I've extracted aroma from the roasted peanut oil. I'm also thinking about killing off the yeast before kegging and adding some honey to lend body, sweetness and complementary aroma, as peanut and honey are a classic combination.
Most peanut beers/talk of peanut beers involves peanut powder, which is the remaining peanut product after pressing roasted peanuts to extract the peanut oil. It seems to me that this is not an ideal ingredient for adding peanut aroma to a beer.
Roasted peanut oil, however, has an intense aroma of roasted peanuts. Further, molecules that provide aroma tend to be highly soluble in fat, so I'd venture to say that a significant portion of the aroma in whole roasted peanuts is extracted alongside the fat during pressing.
So whats left behind after this process? A little checking on peanut flour nutrition facts shows composition (by weight):
50-55% protein
13-20% fat
11-14% fiber
7-12% complex carbohydrates
6-8% simple sugars
Peanuts are approximately 50% fat by weight, so if the product remaining after pressing is ~15% fat, that means ~82% of the fat has been removed, which is a large portion of the material with highest concentration of aroma.
If you add this powder to beer, most of the simple sugars and some of the starches will dissolve into it. Some of the fat will likely separate out of those solids, largely depending upon how it's mixed into the beer. Some fiber is water soluble so you might get some of that. Proteins break down to amino acids in the presence of acid, so you might get some of that dissolving into the beer. All of those things can be desirable in the beer to some extent (excluding the fat) as they would lend body. There will certainly be a line where you have too much "stuff" dissolved into the beer, where it has too much body and you don't want to drink it.
Presumably, the peanut powder would also absorb liquid when added to the beer, reducing the ultimate yield, and accelerating the point at which the remaining beer would have too much stuff dissolved in it. I presume the amount of beer loss due to absorption by the peanut powder would be non-trivial by the time you've added enough peanut butter powder to get a sufficiently intense peanut aroma in the beer.
Flip the script. The roasted peanut oil has a significantly higher concentration of aroma molecules than the powder. Extracting those into a water based solution would allow you to add peanut aroma, and just peanut aroma, to beer.
In the past, I've extracted aroma from fats by mixing them with a strong alcohol solution, mixing, letting the mixture separate, solidifying the fat and the draining off the alcohol solution. This would seemingly be a non-starter for flavoring beer. By the time you've added enough of the "seasoned" alcohol to the beer, I think you would have added enough alcohol to push this well outside the category of beer.
In speaking with a chemist, I was told that the main aroma molecules in peanuts are "not particularly hydrophobic." If so, simple agitation of peanut oil and water (as in, on a stir plate), perhaps with a splash of alcohol added, should be sufficient to extract a noticeable amount of peanut aroma. From there, instead of water, it may be possible to use wort/beer to extract aroma from the peanut oil.
Presuming the extraction works, the question becomes, when should the extraction take place? The reasonable options I can think of are:
1. In the water used to mash
2. In the post boil wort
3. Post fermentation
By extracting peanut aroma to the water used for the mash, you can "season" the entirety of the water without any loss of aroma back to the oil. Which is to say, if you have a bunch of malt aroma in the wort and mix it with the peanut oil, some of the aroma from the peanut oil will make it's way into the wort and some of the aroma of the wart will make it's way into the peanut oil. By using plain water before mashing, you only extract aroma from the peanut oil. The downside though is those aromas will be put through the entire brewing process, during which time you will likely lose a non-trivial amount of intensity.
By extracting peanut aroma to the post boil wort, you avoid the high heat processes that are most likely to drive off aroma molecules. However, you still expose the peanut aroma molecules to the fermentation process. As is noted with hops, fermentation tends to expel some of the aroma. The amount of loss would obvious be less than if the aroma molecules were present for the entire beer brewing process. In addition, extracting to wort will likely emulsify at least a small amount of oil, which will likely preclude any head formation while pouring the finished beer.
By extracting peanut aroma to the post fermentation beer, you avoid all the processes that would lower the intensity of that aroma. However, it becomes more of a challenge to extract the aroma into the finished beer without also incorporating oxygen. It may be possible to perform some kind of pressurized transfer, then encourage extraction of aroma by shaking, then somehow siphon off just the beer, but that also sounds quite difficult.
Of these, I think I'll be trying the post boil, pre fermentation extraction into wort, alongside peanut butter powder on the top of the mash. I'm also thinking of making a bigger, fuller bodied beer with the intention of some dilution post fermentation using water into which I've extracted aroma from the roasted peanut oil. I'm also thinking about killing off the yeast before kegging and adding some honey to lend body, sweetness and complementary aroma, as peanut and honey are a classic combination.
