Tuesday, November 20, 2012

5 Rules You Can't Ignore to Improve Homebrewed Beer




This post will explore the top 5 ways to improve your homebrew beer. As time goes by and my homebrews slowly improve I have tried to reflect on what I have changed in order to increase the quality of my homebrewed beer. As I have moved from extract brewing to all grain homebrewing I have noticed a benefit to brewing in certain ways that retain the quality of my beers over time, aswell as improving beer flavor too. These are my top 5 brewing changes for overall improvement: 


1.   Temperature control:
Homebrew Fermentation Temperature Controller (Johnson Controls)

The Problem:
Yeast derived flavors are highly temperature dependent. From the lightest German Helles to a dark roasty stout, the temperature you ferment at will have a heavy hand in determining the ultimate flavor profile of your homebrew. As a general rule of thumb higher temperatures during fermentation increase ester and higher fusel alcohol production. The flavors often associated with intense ester production are akin to over-ripe fruit. While this is sought after to a certain degree with some beer styles like Belgian Saison or Bavarian Wheat beers, it is never looked kindly upon when there is too much of this flavor. Hot fermentation also causes solvent like flavors from higher weight alcohols called fusel alcohols. These can impart a heat/solvent flavor.

The Solution:
The Quick Answer: Pitch your yeast into the wort at a high temperature like 70-72 degrees F. After 6-12 hours lower the temperature by 3-5 degrees to compensate for heat the yeast will soon generate by fermentation. Monitor the temperature often, and be prepared to lower the temperature further as needed. Do not let the temperature fluctuate suddenly by more than + or – 5 degrees F. After 3-4 days, as fermentation winds down increase the temperature from 68 to 70-72 degrees for the remainder of secondary fermentation. Avoid transferring the beer from a primary to secondary fermentation vessel to avoid oxidation issues. Maintain this high temperature for the entire secondary fermentation phase, usually a good rule of thumb is 1 week for primary, 2 weeks for secondary, and three weeks for bottle conditioning. Darker and higher gravity beers may need to condition longer than this.

The Full Answer: Temperature control especially during the first 1-4 days of primary fermentation will help improve homebrew flavor and attenuation rate. In case you don’t know, attenuation is the percent that yeast convert sugars into alcohol. A higher or lower attenuation rate is simply saying that a particular strain of yeast create more or less alcohol. After primary fermentation has subsided, the fermentation temperature may actually be increased in order to help with attenuation and in the removal of off flavor contributing compounds like diacetyl, pentanedione and fusel alcohols. All of these compounds are natural byproducts of fermentation, though in higher levels can give a buttery flavor to beer or in the case of fusel alcohols may add a solvent/hot flavor to the beer. By ramping up the fermentation temperature during the secondary stage of fermentation, diacetyl, pentanedione and fusel alcohols will be metabolized by the yeast and have their off-flavors removed. Also, remember that aside from chemical byproducts, yeast produce a huge amount of heat. Often times when looking to ferment at say, 68 degrees Fahrenheit, it is advisable to lower the fermentation temperature by 3-5 degrees during the vigorous primary fermentation stage to account for yeast heat produced. Once the primary phase has ended, bring the temperature back up to your target temperature. So if you were looking to ferment around 68 degrees F for example, the order goes:
Yeast inoculation 0-6 hours (highest temperature, for example: 70 F)àPrimary fermentation 3-5 days (reduce temperature to 65 F to hit target of 68 F)àSecondary fermentation(increase temperature to 70-72 F). Leave your beer in the same vessel for the entire fermentation process. As long as you don’t intend to age it on the yeast cake for more than a month you can avoid oxidation issues simply by not racking.

2.   Yeast Health / Pitching Rates
Homebrew Yeast Cells Budding

The Problem:
Beer flavor rides on the health of your yeast. Factors like yeast age, fermentation temperature, temperature swings  and how many yeast cells pitched to inoculate your wort are of utmost importance. Common problems associated with unhealthy yeast, such as yeast that are very old are a stuck fermentation or under attenuation. By overpitching yeast you will actually effect the flavor of your beer down the road. If too many yeast cells exist, ester development (believe it or not, some esters are needed) will be undeveloped.

The Solution:
Warm the liquid yeast first to room temperature for several hours before pitching. If using dry yeast be sure to rehydrate it according to the manufacturer’s directions. Now go to http://www.mrmalty.com and use the pitching rate calculator. Avoid pitching onto another batches yeast cake. If you want you may take the recommended amount from Mr. Malty from the old yeast cake and pitch into your next batch. If not re-pitching from a slurry like this, make a yeast starter. I have written a tutorial here that shows you how to make a yeast starter while simultaneously testing your extract gravity. This will help you to predict your original gravity during recipe formulation. Finally, aerate your pre-fermented wort by shaking vigorously for a minute before pitching your yeast.

3.   Staling Issues From Hot Side Aeration / Post Fermentation Oxidation
Hot side aeration leads to stale cardboard flavor in homebrew beer

The Problem:
When oxygen is introduced to hot wort (>80 F), it will cause staling issues and a wet cardboard flavor in your homebrew beer. While some light oxygen pickup pre-fermentation is ok, too much will leave a noticeable quality loss in your beer. I say that some pickup of hot side aeration is ok since the yeast do a tremendous job of cleaning up by products associated with hot side oxygen pickup, but they can’t remove it all.

The Solution:
Don’t transfer your beer from one vessel to another while it is above 80 degrees Fahrenheit after the primary fermentation phase. Leave the wort to ferment in one container, preferably glass, oxygen resistant plastic or stainless steel. By racking from one vessel to another you will pick up oxygen and stale your homebrew. While racking to keg or bottling be sure to sparge your receiving vessel with co2 or nitrogen, either is fine, though nitrogen has the added benefit of not mixing into solution, while co2 will slightly carbonate your beer. Both gasses are heavier than air and will provide a blanket of inert gas to keep oxygen from reacting with your beer. Co2 costs the least and is a great alternative to nitrogen. Yes, co2 does eventually break down into carboxylic acid (a weak acid at that), but the level is so little that it will not affect your beer’s flavor. Finally, when dry-hopping, be sure to place the hops in your conditioning beer toward the last 80%-90% of fermentation as this will ensure metabolism of oxygen brought into solution from the hops. Rousing your hops daily and sparging any empty headspace daily in your vessel will improve flavor aswell as keep oxygen at bay. I feel this last point is the most important, and I don’t mind repeating myself: Maximum hop flavor from dry hopping can be achieved at warmer temperatures (68-72 F) and from daily rousing. Before I did this I extracted 40%-50% less hop flavor and aroma in my homebrew.


4.   Recipe Formulation:
Various Malted Grains for Homebrewing

The Problem:
Your last batch tasted muddled without much identifiable flavor. The brew was very round and flat, or the opposite, it had a sharp edge of one or two flavors that dominated the balance.

The Solution:
Balance is key to recipe formulation. We are not trying to make big macs here where every ingredient is huge in flavor. Subtle flavors that last are the key because they let you identify and enjoy each ingredient in your homebrew. While this is not true for all styles, for many only a few flavors need be present. If I were on a deserted island but had all the time in the world to homebrew beer there are two books I would want to have with me to help with recipe formulation. Brewing Classic Styles by Jamil Zainasheff, and Designing Great Beers by Ray Danials. If you really want to expand both your perception and knowledge of flavor in beer, read these books and fall asleep with them under your pillow every night! These men are pioneers in our homebrewing community and have solid award winning recipes that are an excellent place to start with recipe formulation. Ray Danials book focuses more on statistical data of ingredients used for award winning beers over the years, while Jamil Zainasheff’s book has over 80 recipes to get you started brewing in the right direction. These books will give you an idea of how much and what types of malt, yeast and hops are used for various beer styles. I started with their recipes, then altered them to suite my own particular tastes. Because of their solid foundation to my homebrewing I now have a better feel for the direction I would like to take their recipe.
One final note about recipe formulation. Think of your recipe like it is a building. Starting with the foundation of your building as base malt. Go to your local homebrew shop and take a few minutes to sample the grains. Yes, I mean literally take a few out of the bin, chew and swallow. What flavors grab your attention? Which grains do you really not care for? Do you want a fairly neutral 2-row pale malt to leave plenty of room for a hefty hop forward beer? Or should I have my foundation be a bisquit like Marris Otter British malt? Once your foundation is clear, subtlety is the name of the game for  the rest of the recipe. Nuances that calmly ride in and out of your palate will merge better than one or two rough edges. Think of specialty malts/grains as the pillars that rise up and out of the founding flavor to embrace and support the overall direction of your beer.

5.   Sanitation / Calibration & Measurement Techniques
Infected Homebrew Beer


The Problem:
Often batches made in environments with poor sanitation practices end up with flavors like iodine (too much iodine sanitizer), vinegar (acetic acid converting ethanol alcohol into vinegar, often carried on fruit flies), or moldy flavors. Without a calibrated and understood brewing system you will never know things that help with consistency from each batch. Efficiency, boil rate, trub loss and grain absorption rates all determine how much beer you can produce and the correct amount of fermentables in your finished product. How will you be able to correct for too low a sugar content in your boiled wort without knowing how much wort you have to correct?

The Solution:
Calibrate your boil kettle and receiving fermentation chamber. Fill your brewing kettle with water in small increments, like 1/10th of a gallon (12.8oz), at each 1/10th gallon place your stirring spoon or a dowel into your pot and draw a line on the spoon or dowel the moment it touches your water level. This will tell you pre and post boil volumes which will later allow you to measure your boil off rate and predict your final boil gravity. Calibrate your receiving fermentation vessel aswell, this will tell you how much hot break / cold break to account for as it may settle in your fermenter if not removed prior to fermentation. With just these two data points you can formulate recipes to give you the exact amount of final homebrewed beer aswell as let you hit your gravity dead on the nose everytime.

 

 Leave a comment!

I can't wait to hear from some of you about ideas you have to improve homebrew beer!

1 comment:

  1. I wish I would have read this post back when I still thought that hot side aeration was a myth. I know now, albeit I learned the hard way.

    ReplyDelete

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