Fermentation & Yeast: The Do's and Don't's of Each
So what's the big deal about fermentation and yeast? Not much really, but if you don't follow these simple tips you ruin your batch of beer. Every batch of beer costs money whether you are brewing 5 gallons or 500 gallons, therefore a loss is a loss. Being that beer takes on average of 6 weeks from start to finish, every ruined batch is 6 more weeks longer you have to wait for the next.
Fermentation is a simple process, and is where the yeast 'feeds' on the fermentable sugars in the wort, converting the sugars into alcohol. During this process co2 is released from the fermentation vessel. A proper airlock with keep any bacterias from entering the fermentation vessel, preventing infection, all the while allowing the escape of co2, allowing the sugars to convert to alcohol. It's a beautiful thing really and without it it would be proof that God hates us all and doesn't want us to be happy. Lucky for us, he does want us to be happy, so this simple phenomena can occur (even at the homebrew level!).
Chronilogically, here is what happens during the brewing and fermentation process: in simple terms.
1.) Steep the grains at the ideal range of 145-158 F. This allows the grains to convert the starches to fermentable sugars. The result of this conversion is called wort.
2.) You then take the wort (malt extract) and add water to your desired batch size, boiling it for 60-90 minutes. A 90 minute boil will allow for a more crisp, dry taste (like a pale ale), versus a 60 minute boil resulting in a creamy, smooth stout (guiness). It affects the body of the beer. This is also where you would add hops and any other additions such as flavorings.
3.) After the boil, you must immediately cool down the wort as fast as possible to about 68 F for ales and 40 F for lagers and then transfer it into your fermentation vessel (typically a closed-lid bucket or carboy).
4.) Once your beer is cooled, you can pitch the yeast (aka, dump the yeast in) and let the fermentation begin. Fermentation can take anywhere from 3 days to weeks and months, depending on the beer.
5.) After fermentation is complete, you then transfer the fermented beer to bottles, adding sugar for carbonation, or to kegs, where you would force carbonate it with co2.
6.) Drink and Enjoy.
As you can see, there are really only a few steps involved in this process. It's because of the simplicity of this process that allowed people to drink beer for thousands of years. Don't be fooled though, it wasn't that easy long long ago. You'd be lucky to have 2 different styles of beer back then. This of course, was long before yeast strains and barleys became part of the international trade system. When thinking about this, think about your regional beers. Germany has a lot of wheat beers, because Germany is home to wheat. England is known for its English Ales because England has Pilsner malt, etc. You get the idea. Each style beer was the only option for beer hundreds of years in that particular part of the world.
And even though it's a simple process we tend to get caught up in the complexity of it all. Take make crazy homemade brewery I have going. I used to make beer using a $40 kit, now I use a handbuilt $.... system. So please, keep these tips for your own success. I've ruined batches before, so I can at least help others from doing it too. However, I'd still bet you my home that you will mess up one time or another.
Tips to Live By:
- Cool down the beer as fast as possible after the boil. The longer it takes to cool down, the more opportunity for bacteria to enter and cause infection. Some people use ice baths to cool down the beer. It can take hours in this process, but sometimes that's the only option. You can buy an immersion chiller http://morebeer.com/view_product/8766//B3-500_Immersion_Chiller_Option for under $60. This will cool the beer down in about 10-15 minutes. You want to cool it down in regards to the yeast you are using. When you transfer the beer to a fermentation vessel, get some oxygen in there, as oxygen help yeast multiply. Pour the beer back and forth from one bucket to another once or twice. That will allow for adequate aeration.
- Use a hydrometer and take a sample of the beer using a sanitized siphon or something of the sort. This is the Original Gravity (OG). Ex. 1.052. You use this number to determine alcohol content and to determine if your beer fermented or not.
-All yeast packages have ideal fermentation temperature ranges, so follow that. Most ales like to ferment between 60-75 F. Most lagers like to ferment at 34 F to 48 F.
- Do not pitch the yeast outside of this range. You can risk killing what were viable yeast cells. A typical dry packet of yeat contains about 200 billion cells, just enough for a 5 gallon batch.
- My personal preference is to ferment in a glass carboy versus plastic buckets. Plastic is porous, and the lids are not airtight. Plus, residues such as soap rinses from glass easier than plastic. You don't want any off-flavors in your beer do you? Oh yeah, you can't see through a white plastic bucket, but can see through glass. I like to watch fermentation from start to finish.
- Look for a layer of krausen (foam) to form within 4-24 hours after pitching the yeast. At this point you MAY or MAY NOT see bubbling occuring in the airlock. It's ok if it does not bubble. DO NOT use bubbling as a source to determine if fermentatin is active. DO NOT!
- After a week or two, take a sample of the beer (with a sanitized utensil!) and check the hydrometer reading again. At this point, the layer of krausen usually recedes and thins out and all airlock activity comes to a halt. The hydrometer reading should be much lower now. Ex. 1.012. This is your Final Gravity (FG).
- Determine alcohol content. Take your OG - FG * 131. In this case, it would be 1.052 -1.012 * 131 = 5.24% ABV. Use your head now. If the ABV is 2.3% then you did something wrong. You have never bought a beer that has that little alcohol, which means your beer is crap. Most beers are 4% or more.
So what's the big deal about fermentation and yeast? Not much really, but if you don't follow these simple tips you ruin your batch of beer. Every batch of beer costs money whether you are brewing 5 gallons or 500 gallons, therefore a loss is a loss. Being that beer takes on average of 6 weeks from start to finish, every ruined batch is 6 more weeks longer you have to wait for the next.
Fermentation is a simple process, and is where the yeast 'feeds' on the fermentable sugars in the wort, converting the sugars into alcohol. During this process co2 is released from the fermentation vessel. A proper airlock with keep any bacterias from entering the fermentation vessel, preventing infection, all the while allowing the escape of co2, allowing the sugars to convert to alcohol. It's a beautiful thing really and without it it would be proof that God hates us all and doesn't want us to be happy. Lucky for us, he does want us to be happy, so this simple phenomena can occur (even at the homebrew level!).
Chronilogically, here is what happens during the brewing and fermentation process: in simple terms.
1.) Steep the grains at the ideal range of 145-158 F. This allows the grains to convert the starches to fermentable sugars. The result of this conversion is called wort.
2.) You then take the wort (malt extract) and add water to your desired batch size, boiling it for 60-90 minutes. A 90 minute boil will allow for a more crisp, dry taste (like a pale ale), versus a 60 minute boil resulting in a creamy, smooth stout (guiness). It affects the body of the beer. This is also where you would add hops and any other additions such as flavorings.
3.) After the boil, you must immediately cool down the wort as fast as possible to about 68 F for ales and 40 F for lagers and then transfer it into your fermentation vessel (typically a closed-lid bucket or carboy).
4.) Once your beer is cooled, you can pitch the yeast (aka, dump the yeast in) and let the fermentation begin. Fermentation can take anywhere from 3 days to weeks and months, depending on the beer.
5.) After fermentation is complete, you then transfer the fermented beer to bottles, adding sugar for carbonation, or to kegs, where you would force carbonate it with co2.
6.) Drink and Enjoy.
As you can see, there are really only a few steps involved in this process. It's because of the simplicity of this process that allowed people to drink beer for thousands of years. Don't be fooled though, it wasn't that easy long long ago. You'd be lucky to have 2 different styles of beer back then. This of course, was long before yeast strains and barleys became part of the international trade system. When thinking about this, think about your regional beers. Germany has a lot of wheat beers, because Germany is home to wheat. England is known for its English Ales because England has Pilsner malt, etc. You get the idea. Each style beer was the only option for beer hundreds of years in that particular part of the world.
And even though it's a simple process we tend to get caught up in the complexity of it all. Take make crazy homemade brewery I have going. I used to make beer using a $40 kit, now I use a handbuilt $.... system. So please, keep these tips for your own success. I've ruined batches before, so I can at least help others from doing it too. However, I'd still bet you my home that you will mess up one time or another.
Tips to Live By:
- Cool down the beer as fast as possible after the boil. The longer it takes to cool down, the more opportunity for bacteria to enter and cause infection. Some people use ice baths to cool down the beer. It can take hours in this process, but sometimes that's the only option. You can buy an immersion chiller http://morebeer.com/view_product/8766//B3-500_Immersion_Chiller_Option for under $60. This will cool the beer down in about 10-15 minutes. You want to cool it down in regards to the yeast you are using. When you transfer the beer to a fermentation vessel, get some oxygen in there, as oxygen help yeast multiply. Pour the beer back and forth from one bucket to another once or twice. That will allow for adequate aeration.
- Use a hydrometer and take a sample of the beer using a sanitized siphon or something of the sort. This is the Original Gravity (OG). Ex. 1.052. You use this number to determine alcohol content and to determine if your beer fermented or not.
-All yeast packages have ideal fermentation temperature ranges, so follow that. Most ales like to ferment between 60-75 F. Most lagers like to ferment at 34 F to 48 F.
- Do not pitch the yeast outside of this range. You can risk killing what were viable yeast cells. A typical dry packet of yeat contains about 200 billion cells, just enough for a 5 gallon batch.
- My personal preference is to ferment in a glass carboy versus plastic buckets. Plastic is porous, and the lids are not airtight. Plus, residues such as soap rinses from glass easier than plastic. You don't want any off-flavors in your beer do you? Oh yeah, you can't see through a white plastic bucket, but can see through glass. I like to watch fermentation from start to finish.
- Look for a layer of krausen (foam) to form within 4-24 hours after pitching the yeast. At this point you MAY or MAY NOT see bubbling occuring in the airlock. It's ok if it does not bubble. DO NOT use bubbling as a source to determine if fermentatin is active. DO NOT!
- After a week or two, take a sample of the beer (with a sanitized utensil!) and check the hydrometer reading again. At this point, the layer of krausen usually recedes and thins out and all airlock activity comes to a halt. The hydrometer reading should be much lower now. Ex. 1.012. This is your Final Gravity (FG).
- Determine alcohol content. Take your OG - FG * 131. In this case, it would be 1.052 -1.012 * 131 = 5.24% ABV. Use your head now. If the ABV is 2.3% then you did something wrong. You have never bought a beer that has that little alcohol, which means your beer is crap. Most beers are 4% or more.
Ok, I could write a whole book on fermentation alone, as well as yeast. So, I have to come back and revisit this topic again. There is too much to talk about, but for the beginner, this should help. We can talk about yeast starters, culturing, harvesting yeast, washing yeast, etc, all at a later time. Just know the key takeaways mentioned above.
Let me know if you have any questions though at any time. Facebook or jkhalbe@gmail.com.
cheers!
No comments:
Post a Comment