My
I'm looking to buy a kegerator and all the equipement necessary for kegging my beer. I want a dual tap kegerator. My budget is $800. Advice?
My Twitter friend B_Pat_ recently asked me:
I'm looking to buy a kegerator and all the equipement necessary for kegging my beer. I want a dual tap kegerator. My budget is $800. Advice?
My Twitter friend B_Pat_ recently asked me:
I'm looking to buy a kegerator and all the equipement necessary for kegging my beer. I want a dual tap kegerator. My budget is $800. Advice?
My Twitter friend B_Pat_ recently asked me:
I'm looking to buy a kegerator and all the equipement necessary for kegging my beer. I want a dual tap kegerator. My budget is $800. Advice?
Along with malt, Hemorrhoids
water, case and hops, illness
yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for yeast in the fermentation process is overlooked by many homebrewers and can often lead to an unhappy batch of beer. Unleashing yeast's full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. Well, a yeast cell is a fungus, yeast are fungi. More specifically, yeast is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, yeast has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the world of beer consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale yeast and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). Ale yeasts are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
life
on Flickr”>Along with malt, health
water, and hops, yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for yeast in the fermentation process is overlooked by many homebrewers and can often lead to an unhappy batch of beer. Unleashing yeast's full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. Well, a yeast cell is a fungus, yeast are fungi. More specifically, yeast is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, yeast has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the world of beer consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale yeast and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). Ale yeasts are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
dosage
on Flickr”>Along with malt, help
water, and hops, yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for yeast in the fermentation process is overlooked by many homebrewers and can often lead to an unhappy batch of beer. Unleashing yeast's full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. Well, a yeast cell is a fungus, yeast are fungi. More specifically, yeast is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, yeast has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the world of beer consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale yeast and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). Ale yeasts are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
pancreatitis
on Flickr”>Along with malt, water, and hops, yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for yeast in the fermentation process is overlooked by many homebrewers and can often lead to an unhappy batch of beer. Unleashing yeast's full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. Well, a yeast cell is a fungus, yeast are fungi. More specifically, yeast is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, yeast has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the world of beer consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale yeast and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). Ale yeasts are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
viagra
on Flickr”>Along with malt, Syphilis
water, medicine
and hops, yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for yeast in the fermentation process is overlooked by many homebrewers and can often lead to an unhappy batch of beer. Unleashing yeast's full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. Well, a yeast cell is a fungus, yeast are fungi. More specifically, yeast is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, yeast has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the world of beer consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale yeast and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). Ale yeasts are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
In Part 1, cheap
we went over some yeast basics, malady
characteristics of Ale and Lager yeast, search
as a very simple overview of the fermentation process. In Part 2, we will go over how understanding the right conditions the yeast need for fermentation will maximize the good flavor potential of the yeast and, just as important, minimize the bad flavor potential. The primary factors are temperature, oxygen, the amount of fermentable sugars, the amount of yeast pitched, and viability of the yeast.
It is important to stay within the temperature range of the variety of yeast used during the fermentation period. Too far above the temperature range and the yeast can produce a variety of exciting flavors, almost all of which taste bad. Too far below and the yeast may just sit there and do nothing. Especially with Ales, too high of a temperature can set the right conditions for bacteria to beat the yeast to the sugars and may contaminate the batch.
Oxygen is a factor that a lot of homebrewers forget about. Prior to pitching the yeast, it is important to agitate the wort or use a beer stone (air stone) to dissolve oxygen in the wort. Gasses, like oxygen, dissolve better at lower temperatures. Therefore, the heat of the brewing process depletes much of the oxygen dissolved in the wort. It is best to let the wort cool to the required temperature before stirring, shaking, or otherwise agitating the wort to dissolve the necessary oxygen.
The more fermentable sugars in the wort, the higher the potential alcohol content of the finished beer. The desired alcohol content is an important consideration in choosing which yeast variety to use. Ale and Lager yeasts do not tolerate high levels of alcohol well. They will usually keep fermenting until the alcohol level reaches about 8.5%. Around this point the yeast can become stressed and produce undesirable flavors and aromas as they stagger away drunk. For beer styles which have a higher than 8.5% Alcohol by Volume percentage (% ABV), it is best to use a yeast variety that has a higher alcohol tolerance, such as champagne yeast.
When determining how much yeast to pitch into the wort, it is better to pitch too much yeast than too little. Too little yeast can cause a prolonged lag time giving other beasts, like bacteria, the edge to beat the yeast for dominance of the sweet sugars. Ideally the lag time between pitching the yeast and the yeast being thoroughly engaged in the fermentation process should not be more than a day. Worrying about the amount of yeast to pitch only really comes into play with homebrewers who culture their own yeast or for recipes with high specific gravity wort (more fermentable sugars) where the risk of contamination is slightly higher. Most commercially purchased yeast varieties, whether dry or liquid, are more than enough for a typical five gallon batch. Be sure to follow the directions for preparing the yeast carefully to ensure the yeast get a good start. For high specific gravity beers, seriously consider doubling the amount of yeast pitched.
Yeast viability is not much of an issue with commercially purchased yeast varieties as long as the yeast is stored properly and used before the expiration date. Similar to determining the amount of yeast to pitch, yeast viability only really becomes a factor for those who culture their own variety of yeast or harvest yeast from their favorite commercial beer. Old, tired, and/or mutated yeast can inhibit a clean fermentation process and produce a lot of uncharacteristic bad flavors.
Regardless of the variety of yeast you choose to craft your beer, it is important to give the little guys the right environment to maximize their career potential. Though the flavor impact of yeast on beer is often less subtle than its hops or malt counterparts, yeast can give a beer the flavor edge it needs to be great. Happy brewing!
prescription
on Flickr” target=”_blank”>In Part 1, we went over some yeast basics, characteristics of Ale and Lager yeast, as a very simple overview of the fermentation process. In Part 2, we will go over how understanding the right conditions the yeast need for fermentation will maximize the good flavor potential of the yeast and, just as important, minimize the bad flavor potential. The primary factors are temperature, oxygen, the amount of fermentable sugars, the amount of yeast pitched, and viability of the yeast.
It is important to stay within the temperature range of the variety of yeast used during the fermentation period. Too far above the temperature range and the yeast can produce a variety of exciting flavors, almost all of which taste bad. Too far below and the yeast may just sit there and do nothing. Especially with Ales, too high of a temperature can set the right conditions for bacteria to beat the yeast to the sugars and may contaminate the batch.
Oxygen is a factor that a lot of homebrewers forget about. Prior to pitching the yeast, it is important to agitate the wort or use a beer stone (air stone) to dissolve oxygen in the wort. Gasses, like oxygen, dissolve better at lower temperatures. Therefore, the heat of the brewing process depletes much of the oxygen dissolved in the wort. It is best to let the wort cool to the required temperature before stirring, shaking, or otherwise agitating the wort to dissolve the necessary oxygen.
The more fermentable sugars in the wort, the higher the potential alcohol content of the finished beer. The desired alcohol content is an important consideration in choosing which yeast variety to use. Ale and Lager yeasts do not tolerate high levels of alcohol well. They will usually keep fermenting until the alcohol level reaches about 8.5%. Around this point the yeast can become stressed and produce undesirable flavors and aromas as they stagger away drunk. For beer styles which have a higher than 8.5% Alcohol by Volume percentage (% ABV), it is best to use a yeast variety that has a higher alcohol tolerance, such as champagne yeast.
When determining how much yeast to pitch into the wort, it is better to pitch too much yeast than too little. Too little yeast can cause a prolonged lag time giving other beasts, like bacteria, the edge to beat the yeast for dominance of the sweet sugars. Ideally the lag time between pitching the yeast and the yeast being thoroughly engaged in the fermentation process should not be more than a day. Worrying about the amount of yeast to pitch only really comes into play with homebrewers who culture their own yeast or for recipes with high specific gravity wort (more fermentable sugars) where the risk of contamination is slightly higher. Most commercially purchased yeast varieties, whether dry or liquid, are more than enough for a typical five gallon batch. Be sure to follow the directions for preparing the yeast carefully to ensure the yeast get a good start. For high specific gravity beers, seriously consider doubling the amount of yeast pitched.
Yeast viability is not much of an issue with commercially purchased yeast varieties as long as the yeast is stored properly and used before the expiration date. Similar to determining the amount of yeast to pitch, yeast viability only really becomes a factor for those who culture their own variety of yeast or harvest yeast from their favorite commercial beer. Old, tired, and/or mutated yeast can inhibit a clean fermentation process and produce a lot of uncharacteristic bad flavors.
Regardless of the variety of yeast you choose to craft your beer, it is important to give the little guys the right environment to maximize their career potential. Though the flavor impact of yeast on beer is often less subtle than its hops or malt counterparts, yeast can give a beer the flavor edge it needs to be great. Happy brewing!
seek on Flickr”>Along with malt, water, and hops, yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for the fermentation process is overlooked by many homebrewers, which can often lead to an unhappy batch of beer. Unleashing the full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. More specifically, it is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, it has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the beer world consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). These are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
cheap
on Flickr”>Along with malt, hospital water, and hops, yeast is one of the four necessary pillars of beer. Each element adds its own unique set of characteristics to the beer, though the influence of yeast is often misunderstood. Ensuring the right conditions for yeast in the fermentation process is overlooked by many homebrewers and can often lead to an unhappy batch of beer. Unleashing yeast's full potential in your beer can be that extra bit of magic that turns a mediocre batch of beer into a great one.
First, a little yeast basics. Yeast is a fungus. Well, a yeast cell is a fungus, yeast are fungi. More specifically, yeast is a single-cell organism that got stuck in its evolutionary development somewhere between an animal and plant. The individual yeast cell has characteristics similar to a plant cell, such as a cell wall. Unlike most plant cells, yeast has no chlorophyll to help produce sugars from carbon dioxide and sunlight. There are many different varieties of yeasts, but the ones that are of importance in the world of beer consume sugars located in their immediate environment to produce carbon dioxide and ethyl alcohol in a process called fermentation. In order to metabolize these sugars, the yeast cell requires oxygen, like an animal cell.
There are two types of yeast that are of primary concern to homebrewers: Ale yeast and Lager yeast. Among these two types are many strains that have been crafted over the centuries to produce a variety of subtle flavors which have become cornerstones of many beer styles.
The scientific name for Ale yeast is Saccharomyces cerevisiae (or just S. cerevisiae). Ale yeasts are typically characterized by being top -fermenting yeasts, in that they hang around the top of the fermenter, and prefer warmer temperatures, around 60 to 70 degrees Fahrenheit. The warm temperature allows for a quicker fermentation period. The yeast will consume the majority of fermentable sugars in a five-gallon batch of beer in between 3 to 5 days. Also as a result of the warmer fermentation temperatures, Ale yeasts tend to produce complexity of flavors, particularly fruity and flowery (estery) flavors.
The Lager yeast's scientific name is Saccharomyces uvarum (S. uvarum). Lager yeasts are bottom fermenting yeasts that prefer colder temperatures between 38 and 50 degrees Fahrenheit. The colder temperatures greatly slow down the fermentation process, so fermentation can take months. The long wait is worth it. The product of this long fermentation is a clean, clear, and crisp beer without the fruity and estery flavors notable in Ales.
In the fermentation process, yeast will take in some oxygen, then use that oxygen to metabolize sugar into carbon dioxide and ethyl alcohol. Once the yeast cell gathers enough energy, it will clone itself by splitting into two new yeast cells. This process repeats itself until the yeast either runs out of oxygen and sugars and begins to flocculate (clump in groups) falling to the bottom as sediment, or the levels of alcohol become too high, at which point the yeast cells become drunk and quit their jobs.
In Part 2, we will go over the necessary conditions that influence yeast in the fermentation process to produce the best results. Until then…
cheapest
on Flickr” target=”_blank”>In Part 1, we went over some yeast basics, characteristics of Ale and Lager yeast, as a very simple overview of the fermentation process. In Part 2, we will go over how understanding the right conditions the yeast need for fermentation will maximize the good flavor potential of the yeast and, just as important, minimize the bad flavor potential. The primary factors are temperature, oxygen, the amount of fermentable sugars, the amount of yeast pitched, and viability of the yeast.
It is important to stay within the temperature range of the variety of yeast used during the fermentation period. Too far above the temperature range and the yeast can produce a variety of exciting flavors, almost all of which taste bad. Too far below and the yeast may just sit there and do nothing. Especially with Ales, too high of a temperature can set the right conditions for bacteria to beat the yeast to the sugars and may contaminate the batch.
Oxygen is a factor that a lot of homebrewers forget about. Prior to pitching the yeast, it is important to agitate the wort or use a beer stone (air stone) to dissolve oxygen in the wort. Gasses, like oxygen, dissolve better at lower temperatures. Therefore, the heat of the brewing process depletes much of the oxygen dissolved in the wort. It is best to let the wort cool to the required temperature before stirring, shaking, or otherwise agitating the wort to dissolve the necessary oxygen.
The more fermentable sugars in the wort, the higher the potential alcohol content of the finished beer. The desired alcohol content is an important consideration in choosing which yeast variety to use. Ale and Lager yeasts do not tolerate high levels of alcohol well. They will usually keep fermenting until the alcohol level reaches about 8.5%. Around this point the yeast can become stressed and produce undesirable flavors and aromas as they stagger away drunk. For beer styles which have a higher than 8.5% Alcohol by Volume percentage (% ABV), it is best to use a yeast variety that has a higher alcohol tolerance, such as champagne yeast.
When determining how much yeast to pitch into the wort, it is better to pitch too much yeast than too little. Too little yeast can cause a prolonged lag time giving other beasts, like bacteria, the edge to beat the yeast for dominance of the sweet sugars. Ideally the lag time between pitching the yeast and the yeast being thoroughly engaged in the fermentation process should not be more than a day. Worrying about the amount of yeast to pitch only really comes into play with homebrewers who culture their own yeast or for recipes with high specific gravity wort (more fermentable sugars) where the risk of contamination is slightly higher. Most commercially purchased yeast varieties, whether dry or liquid, are more than enough for a typical five gallon batch. Be sure to follow the directions for preparing the yeast carefully to ensure the yeast get a good start. For high specific gravity beers, seriously consider doubling the amount of yeast pitched.
Yeast viability is not much of an issue with commercially purchased yeast varieties as long as the yeast is stored properly and used before the expiration date. Similar to determining the amount of yeast to pitch, yeast viability only really becomes a factor for those who culture their own variety of yeast or harvest yeast from their favorite commercial beer. Old, tired, and/or mutated yeast can inhibit a clean fermentation process and produce a lot of uncharacteristic bad flavors.
Regardless of the variety of yeast you choose to craft your beer, it is important to give the little guys the right environment to maximize their career potential. Though the flavor impact of yeast on beer is often less subtle than its hops or malt counterparts, yeast can give a beer the flavor edge it needs to be great. Happy brewing!
prostate
on Flickr”>In Part 1, we went over some yeast basics, characteristics of Ale and Lager yeast, as a very simple overview of the fermentation process. In Part 2, we will go over how understanding the right conditions the yeast need for fermentation will maximize the good flavor potential of the yeast and, just as important, minimize the bad flavor potential. The primary factors are temperature, oxygen, the amount of fermentable sugars, the amount of yeast pitched, and viability of the yeast.
It is important to stay within the temperature range of the variety of yeast used during the fermentation period. Too far above the temperature range and the yeast can produce a variety of exciting flavors, almost all of which taste bad. Too far below and the yeast may just sit there and do nothing. Especially with Ales, too high of a temperature can set the right conditions for bacteria to beat the yeast to the sugars, which can contaminate the batch.
Oxygen is a factor that a lot of homebrewers forget about. Prior to pitching the yeast, it is important to agitate the wort or use a beer stone (air stone) to dissolve oxygen in the wort. Gasses, like oxygen, dissolve better at lower temperatures. Therefore, the heat of the brewing process depletes much of the oxygen dissolved in the wort. It is best to let the wort cool to the required temperature before stirring, shaking, or otherwise agitating the wort to dissolve the necessary oxygen.
The more fermentable sugars in the wort, the higher the potential alcohol content of the finished beer. The desired alcohol content is an important consideration in choosing which yeast variety to use. Ale and Lager yeasts do not tolerate high levels of alcohol well. They will usually keep fermenting until the alcohol level reaches about 8.5%. Around this point the yeast can become stressed and produce undesirable flavors and aromas as they stagger away drunk. For beer styles that have a higher than 8.5% Alcohol by Volume percentage (% ABV), it is best to use a yeast variety that has a higher alcohol tolerance, such as champagne yeast.
When determining how much yeast to pitch into the wort, it is better to pitch too much yeast than too little. Too little yeast can cause a prolonged lag time, giving other beasts, like bacteria, the edge to beat the yeast for dominance of the sweet sugars. Ideally the lag time between pitching the yeast and the yeast being thoroughly engaged in the fermentation process should not be more than a day. Worrying about the amount of yeast to pitch only really comes into play with homebrewers who culture their own yeast or for recipes with high specific gravity wort (more fermentable sugars) where the risk of contamination is slightly higher. Most commercially purchased yeast varieties, whether dry or liquid, are more than enough for a typical five-gallon batch. Be sure to follow the directions for preparing the yeast carefully to ensure the yeast get a good start. For high specific gravity beers, seriously consider making a yeast starter or doubling the amount of yeast pitched. Carl will be talking about yeast starters in a future post, hopefully soon.
Yeast viability is not much of an issue with commercially purchased yeast varieties, as long as the yeast is stored properly and used before the expiration date. Similar to determining the amount of yeast to pitch, yeast viability only really becomes a factor for those who culture their own variety of yeast or harvest yeast from their favorite commercial beer. Old, tired, and/or mutated yeast can inhibit a clean fermentation process and produce a lot of uncharacteristic bad flavors.
Regardless of the variety of yeast you choose to craft your beer, it is important to give the little guys the right environment to maximize their career potential. Though the flavor impact of yeast on beer is often less subtle than its hops or malt counterparts, yeast can give a beer the flavor edge it needs to be great. Happy brewing!
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on Flickr”>Andy and I have been yammering on a bit about yeast this week, apoplexy
since it is Yeast Week here at RealHomebrew.com. Some companies have Shark Week. We have Yeast Week. It's just as frightful and exciting, though on a microscopic level. One issue we have mentioned but never delved into is that of yeast starters. A yeast starter is like a mini-batch of weak beer designed to let your yeast grow and multiply before you add it to the wort. This increases the potential efficiency of the yeast.
One thing many people seem to agree on is that if you use dry yeast, you do not need to use a starter. Most commercially available dry yeasts have about 200-250 billion cells already, and will have instructions on how to rehydrate the yeast and at what temperature to pitch and ferment it. To put this in perspective, a normal five-gallon batch of beer needs something on the order of 180-200 billion yeast cells to properly ferment. If you like using liquid yeasts, however, you definitely should use a starter of some sort. Both White Labs and Wyeast have about 100 billion yeast cells in their products, so they are great candidates to make starters with. If you look merely at the price of yeasts, you may be wondering why you should go for a liquid variety at all. The dry yeast packs have more cells, are cheaper, and require less handling. Why go with liquid? The answer is easy. You have more variety in liquid yeast than you do with dry styles, so sometimes it makes sense to go with liquid.
When you get your yeast home and are ready to make a starter, you have a couple different ways to proceed. You can either use a stir plate, which will be more efficient, or go without and just take a more hands-on approach. A stir plate constantly stirs your yeast slurry and draws oxygen into the mixture by creating a vortex, as in the photo above. I bought my stir plate for $45 but they are easy to make as well, if you are more industrious than lazy, which I am apparently not.
If you don't use a stir plate, you have to swish the starter around in the bottle several times a day to mix it and draw oxygen into the wort. It's not a big deal, just requires some extra maintenance.
Plan on allowing your starter to sit and grow for about 48 hours before you use it. I made my last starter on a Saturday and brewed on a Monday. That is about the right amount of time to let it do its thing.
Getting Started
First, remove your yeast from the refrigerator and let it sit out for a couple hours so it can slowly warm up to the ambient temperature. If you are using a Wyeast smack pack, follow the normal process of smacking it and letting it get all big and bulgy before beginning to make your starter.
Most beers can use a one-liter starter but bigger beers, like barley wines, may need more yeast growth and deserve at least a two-liter starter. Make a 10:1 ratio of water to light dry malt extract (DME). Heat this to boiling and cook it for 10-15 minutes. Cover the pot and put it in an ice bath in the sink to cool it to room temperature. Pour it into a sanitized Erlenmeyer flask or empty bottle and add your yeast. If you are using a stir plate, put in the sanitized stir bar at this point.
Cover the mouth of the flask or bottle with sanitized aluminum foil, allowing some room for air to get in and out. As the yeast grows, it will need some new oxygen to come in. Loose aluminum foil is a good option because it can let a little gas exchange but will be enough of a mechanical barrier to keep harmful bacteria out. Whatever you do, do not use an air lock. That will only allow the carbon dioxide to escape and will not let any new oxygen in.
Put the flask on the stir plate and adjust the speed so that you get a slight vortex. If you are not using a plate, simply swish it around the jar for about a minute. Do this a few times per day.
The night before you brew, put the yeast starter slurry in the refrigerator overnight. This will allow the yeast to settle to the bottom of the container so you can gently pour off the beer the top. Let it come back to room temperature, mix it up again, and pour it in your wort when you are ready. Be careful pouring out your starter, though, because it is easy to lose the stir bar in your fermenter.
Making a yeast starter is easy and can definitely help you get a more thorough fermentation.