- Joined
- Apr 6, 2009
- Messages
- 418
- Reaction score
- 5
I could not decide if I should post this in the beer chemistry or yeast section or in the bottling/kegging section. I decided to go with bottling/kegging, since this is really about modifications to that process.
I have been thinking a lot about carbonating beer lately and different ways it can be done and the possible results of each of those methods. I have also been thinking about why we carbonate beer. This is a rambling of my thoughts on the topic preceded by a few questions about alternative carbing methods.
Questions:
Discussion:
Yeast Carbing vs Sugar Carbing:
Yeast Carbing and Sugar Carbing are both types of Bottle Carbing. I have never heard of Yeast Carbing and am making it up or the sake of this discussion, but I am thinking of trying it.
Bottle Carbing is typically done through a method I call "Sugar Carbing". A small amount of sugar (100-300g/5G) is added to your beer and the beer is promptly bottled. The live yeast remaining in the beer get happy, burp and fart, and in a few weeks to months you have carbonated beer. If the yeast was already dead, filtered out, or killed, some people will add a new (usually of the same type or a champagne type) yeast and some sugar in order to carbonate the beer. Either way, you are adding sugar to the beer in order to carbonate it.
Yeast carbing would be done as follows: Brew beer with Yeast A, at bottling time add Yeast B. Yeast B would have a higher rate of attenuation than Yeast A (e.g., it would eat more of the malt sugars than A). Yeast B would be added in an amount adequate to help it get to work and eat additional sugars in the already brewed beer. No new sugar would be added. Yeast B would then eat some of the existing sugars in the beer, do its burping and farting, and carbonate the beer. Yeast B would probably have to have a rate of attenuation somewhat close to that of Yeast A so you would not overcarb.
Carbonation Flavors:
Carbonation changes the flavor of beer (it also changes the mouth feel). Proof: A lot of beer tastes nasty once it loses its carbonation. But how does it change the flavor?
First, carbonation triggers the sour-sensing cells on the tongue, which helps counter some of the sweetness that can be present in the beer and overcomes other flavors that may exist. That is, carbonation gives the liquid an acidic bite and a little tingle on the tongue. See Tongue's Sour-sensing Cells Taste Carbonation.
Second, carbonation releases aerosols at the surface of the liquid. These aerosols splash up, fill the glass with gasses, and tickle your nose. That is, they give us that first impression through the front of our nose and taste is to a large degree based upon smell. In fact, our tongue is rather limited in what it can taste (bitter, salty, sour, sweet, savory/non-salty). As a result, most of our sense of taste comes through the sensations experienced by our nose. Thus, the aerosols in carbonated drinks enhance the flavor of the drink. Especially if those aerosols have other chemicals in them, that impart other flavors and smells (e.g., beer esters). See Champagne Flavor in the Bubbles; Unraveling different chemical fingerprints between a champagne wine and its aerosols.
Third, carbonation aerosols and other scents related with the liquid you are consuming (beer) are released retronasally, which is the human's richest ability to smell, and where most of the flavor in food comes from. See The Human Sense of Smell: Are We Better Than We Think?.
Combined, the carbonation of beer imparts a surprising amount of its potential flavors. Unfortunately, we often hide these flavors with strong, cloying hops. Yet, the esters and carbonation are where a lot of the unique flavors in Bavarian Hefeweizens and Belgium Witbiers come from. As a result, I ask - can we play with these flavors at bottling time?
Relationship Between Carbonation Method and Flavor:
The following is entirely speculative.
I hypothesize that the carbonation method affects the flavor of beer. Different carbonation methods will result in different aerosols and different amounts of aerosols, which will change the aromas of the beer that are released when the bubbles fizz up to the top. As a result, the carbonation method is as important as the hops you pick out in order to impart the most desirable flavors that you seek.
Mass produced beers (e.g., Budweiser, Pabst, Millers) are almost universally force carbonated. Force carbonation uses a neutral flavor CO2 gas or Nitrogen (mm, rich and silky .. is there any way to bottle carb Nitrogen?). Unfortunately, the neutral flavor gasses don't impart a lot of flavor on their own. Instead, you are dependent on picking up aerosols as they percolate through the beer and to your nose. In fact, if you carb and uncarb your beer enough times you can strip it of flavor compounds (good way to get rid of way too many banana esters). NOTE: I am not saying that force carbing is in any way inferior to bottle carbing. I am instead saying that it potentially picks up less aerosols that are released when you are smelling/drinking your beer, this can be a good thing in some beers. Albeit, I suspect this is why a lot of mass produced American Hefeweizens suck and a small part of why a lot of mass produced beers suck. Nevertheless, in the right situation force carbing can impart exactly the flavors you want. In fact, I wonder if it would be possible to perfume CO2 with edible aerosols so as to impart different and unique, but controlled, flavors to your beer.
In contrast, bottle carbing uses the natural yeast in the brew to create the CO2. As a result, the yeast releases additional aerosols with the CO2 and your carbonation has a higher potential for flavor as a direct result of yeast intervention (not using a neutrally flavored CO2). Bottle carbing is not dependent on picking up aerosols as the carbonation percolates to the top, instead it is already in it as a result of the yeast putting out aromas alongside the CO2. This potentially means there is a lot of room for playing around with the flavor of a beer based on how you bottle carb it.
For example, if you bottle carb with different types of sugars you get slightly different flavors in your beer. Part of this is due to the residual sweetness left by the sugar and part is by other residual flavors of the sugar (e.g., honey). On the other hand, some sugars result in the yeast behaving differently (e.g., malt, corn sugar, beet sugar, cane sugar) and give off different flavors (e.g., cidery, sweet). Thus, the sugar you use can greatly affect the end flavor of your beer by changing the aerosol compounds in the CO2.
On top of that, different yeasts give off different amounts of flavor compounds. Hefeweizen yeasts are famous for their estery (e.g., clove and banana) aerosols and flavoring. This seems to imply that you could get really interesting results by brewing your beer with one yeast - a yeast that imparts flavors that you want in the liquid - and carbonating with another yeast - a yeast that imparts flavors that you want in the aerosols. And, as long as you are changing yeasts you might be able to get away with different tricks. For example, instead of adding a sugar that was never present in your original beer, you could use a yeast that would eat more of the sugars already present in the beer and use those sugars to carbonate. That means you are not adding new, residual flavors from sugars, but instead changing the profile with the yeast used and changing the beer a bit. I suspect that using this method you could come up with some very interesting brews and flavors not typical to your brew.
Done!
Thus, has anyone tried or heard of yeast carbing (or whatever its proper name is)? What are the results? And, what do people think of my thoughts on this? Am I running up a path that goes nowhere, or is it possible there is something to this?
Best,
- M
I have been thinking a lot about carbonating beer lately and different ways it can be done and the possible results of each of those methods. I have also been thinking about why we carbonate beer. This is a rambling of my thoughts on the topic preceded by a few questions about alternative carbing methods.
Questions:
- Is it possible to yeast carb instead of sugar carb? If so, what is the difference in result? (Details of what I mean by Yeast Carbing and Sugar Carbing in my discussion below.)
- What flavors do you get from carbonating your beer? Do different methods of carbonation result in different flavors?
- Bottle carbing vs Forced carbing, which tastes better - which gives the most flavor?
Discussion:
Yeast Carbing vs Sugar Carbing:
Yeast Carbing and Sugar Carbing are both types of Bottle Carbing. I have never heard of Yeast Carbing and am making it up or the sake of this discussion, but I am thinking of trying it.
Bottle Carbing is typically done through a method I call "Sugar Carbing". A small amount of sugar (100-300g/5G) is added to your beer and the beer is promptly bottled. The live yeast remaining in the beer get happy, burp and fart, and in a few weeks to months you have carbonated beer. If the yeast was already dead, filtered out, or killed, some people will add a new (usually of the same type or a champagne type) yeast and some sugar in order to carbonate the beer. Either way, you are adding sugar to the beer in order to carbonate it.
Yeast carbing would be done as follows: Brew beer with Yeast A, at bottling time add Yeast B. Yeast B would have a higher rate of attenuation than Yeast A (e.g., it would eat more of the malt sugars than A). Yeast B would be added in an amount adequate to help it get to work and eat additional sugars in the already brewed beer. No new sugar would be added. Yeast B would then eat some of the existing sugars in the beer, do its burping and farting, and carbonate the beer. Yeast B would probably have to have a rate of attenuation somewhat close to that of Yeast A so you would not overcarb.
Carbonation Flavors:
Carbonation changes the flavor of beer (it also changes the mouth feel). Proof: A lot of beer tastes nasty once it loses its carbonation. But how does it change the flavor?
First, carbonation triggers the sour-sensing cells on the tongue, which helps counter some of the sweetness that can be present in the beer and overcomes other flavors that may exist. That is, carbonation gives the liquid an acidic bite and a little tingle on the tongue. See Tongue's Sour-sensing Cells Taste Carbonation.
Second, carbonation releases aerosols at the surface of the liquid. These aerosols splash up, fill the glass with gasses, and tickle your nose. That is, they give us that first impression through the front of our nose and taste is to a large degree based upon smell. In fact, our tongue is rather limited in what it can taste (bitter, salty, sour, sweet, savory/non-salty). As a result, most of our sense of taste comes through the sensations experienced by our nose. Thus, the aerosols in carbonated drinks enhance the flavor of the drink. Especially if those aerosols have other chemicals in them, that impart other flavors and smells (e.g., beer esters). See Champagne Flavor in the Bubbles; Unraveling different chemical fingerprints between a champagne wine and its aerosols.
Third, carbonation aerosols and other scents related with the liquid you are consuming (beer) are released retronasally, which is the human's richest ability to smell, and where most of the flavor in food comes from. See The Human Sense of Smell: Are We Better Than We Think?.
Combined, the carbonation of beer imparts a surprising amount of its potential flavors. Unfortunately, we often hide these flavors with strong, cloying hops. Yet, the esters and carbonation are where a lot of the unique flavors in Bavarian Hefeweizens and Belgium Witbiers come from. As a result, I ask - can we play with these flavors at bottling time?
Relationship Between Carbonation Method and Flavor:
The following is entirely speculative.
I hypothesize that the carbonation method affects the flavor of beer. Different carbonation methods will result in different aerosols and different amounts of aerosols, which will change the aromas of the beer that are released when the bubbles fizz up to the top. As a result, the carbonation method is as important as the hops you pick out in order to impart the most desirable flavors that you seek.
Mass produced beers (e.g., Budweiser, Pabst, Millers) are almost universally force carbonated. Force carbonation uses a neutral flavor CO2 gas or Nitrogen (mm, rich and silky .. is there any way to bottle carb Nitrogen?). Unfortunately, the neutral flavor gasses don't impart a lot of flavor on their own. Instead, you are dependent on picking up aerosols as they percolate through the beer and to your nose. In fact, if you carb and uncarb your beer enough times you can strip it of flavor compounds (good way to get rid of way too many banana esters). NOTE: I am not saying that force carbing is in any way inferior to bottle carbing. I am instead saying that it potentially picks up less aerosols that are released when you are smelling/drinking your beer, this can be a good thing in some beers. Albeit, I suspect this is why a lot of mass produced American Hefeweizens suck and a small part of why a lot of mass produced beers suck. Nevertheless, in the right situation force carbing can impart exactly the flavors you want. In fact, I wonder if it would be possible to perfume CO2 with edible aerosols so as to impart different and unique, but controlled, flavors to your beer.
In contrast, bottle carbing uses the natural yeast in the brew to create the CO2. As a result, the yeast releases additional aerosols with the CO2 and your carbonation has a higher potential for flavor as a direct result of yeast intervention (not using a neutrally flavored CO2). Bottle carbing is not dependent on picking up aerosols as the carbonation percolates to the top, instead it is already in it as a result of the yeast putting out aromas alongside the CO2. This potentially means there is a lot of room for playing around with the flavor of a beer based on how you bottle carb it.
For example, if you bottle carb with different types of sugars you get slightly different flavors in your beer. Part of this is due to the residual sweetness left by the sugar and part is by other residual flavors of the sugar (e.g., honey). On the other hand, some sugars result in the yeast behaving differently (e.g., malt, corn sugar, beet sugar, cane sugar) and give off different flavors (e.g., cidery, sweet). Thus, the sugar you use can greatly affect the end flavor of your beer by changing the aerosol compounds in the CO2.
On top of that, different yeasts give off different amounts of flavor compounds. Hefeweizen yeasts are famous for their estery (e.g., clove and banana) aerosols and flavoring. This seems to imply that you could get really interesting results by brewing your beer with one yeast - a yeast that imparts flavors that you want in the liquid - and carbonating with another yeast - a yeast that imparts flavors that you want in the aerosols. And, as long as you are changing yeasts you might be able to get away with different tricks. For example, instead of adding a sugar that was never present in your original beer, you could use a yeast that would eat more of the sugars already present in the beer and use those sugars to carbonate. That means you are not adding new, residual flavors from sugars, but instead changing the profile with the yeast used and changing the beer a bit. I suspect that using this method you could come up with some very interesting brews and flavors not typical to your brew.
Done!
Thus, has anyone tried or heard of yeast carbing (or whatever its proper name is)? What are the results? And, what do people think of my thoughts on this? Am I running up a path that goes nowhere, or is it possible there is something to this?
Best,
- M
