Don't be a yeast dominatrix

I could probably write a whole blog about my sins against yeast.  I have starved them, exposed them to extremes of hot and cold, overworked them, choked them off from air, made them wear a ball gag and a ballerina outfit, and in general abused them.  I have been the Stalin of  the yeast world.

On about the same level as proper sanitation, I think understanding fermentation is one of the most important steps in quality beer.  With proper fermentation even extract beers can be pretty good.  Before a new homebrewer wants to jump into all-grain brewing, they need to understand yeast. 

Making beer is a multi step process.  While you are actually brewing you are actively doing something.  You are adding malts and hops, and probably drinking beer.  It is fun and engaging.  The fermentation is boring and takes what seems like forever.  But it is as important, if not more important, than the actual brew day in making good beer.  Yeast is a living organism, kind of a fungus, and like all other organisms it thrives when conditions are just right.  Your wort is extremely rich in food and when the yeast come into this buffet they will go crazy in an orgy of gluttony and reproduction.  It's like Studio 54 in there.

 As a defence mechanism against other single celled organisms the yeast protect their feast by producing a chemical which is deadly to the huge majority of bacteria, alcohol.  As they consume sugar and excrete alcohol they will also be breathing the oxygen dissolved in the wort and exhaling CO2. 

The other big yeast byproduct we are concerned about are chemical compounds called esters.  Think of this as kind of like sweat.  In humans a small amount of sweat is OK, it contains pheromones and can be perceived as pleasant.  However, in large quantities it is BO, which nobody likes.  But, different yeasts produce different esters and react to stimulus in different ways.  In beer, esters contribute fruity flavors, like bananas or cloves or almost stone fruit flavors, like a hint of cherry or plum.  These flavors are great in a Hefeweisen and some Belgians, but not what you are looking for in a lager.  

The biggest mistake I have made towards yeast is considering it an ingredient instead of a living organism.  An ingredient you add and it does what it does.  You toss red paint on a wall and it turns red.  You put black patent malt in a beer and it turns dark.  In order to get the yeast to do what you want them to do you have to manipulate them.  Yeast acts just like people in a given situation.

Nobody likes to be overworked.  So you have a vial of yeast, which is around 3.5 million cells or so when fresh, but the cells are all dormant and asleep and pitch it into your beer.  What happens?

 It is an extremely rich environment and they wake from a sound sleep with everything they could ever want and need to flourish.  They just need to work for it.  So of course, about half of them panic, become stressed out and die. This leaves the other half behind the eight ball and they have to work twice as hard to eat and reproduce, which takes time and causes stress, which produces esters. One trick to lessen the shock to the yeast is to make a yeast starter.  A couple of days before you plan to brew take a little DME, I use around 1/2 a cup for 1500 mL and boil it for 10 minutes.  Then cool it down and pitch your yeast.  This will get the yeast colony growing and building before you dump them in your wort. 

For more in depth information on the amount of starter you should make, check out the starter calculate at mrmalty.com.

                 

Damn it!  Who messed with the thermostat?

Every yeast is designed to work best at a certain temp and you will get hugely different results in flavor depending on temps.  If a yeast is running to warm, it sweats and produces esters, or nothing will happen at all if the yeast is to cold because it is shivering its ass off.  If it gets too cold it will even go dormant. 

Even worse is if your yeast get warm during the day and then cold at night.  It doesn't know what to do.  Just like at work, who wants to be sweating in the morning when the heat is on but have to wear a jacket when the AC kicks in.

This is what I do and it is a bit of an investment.  I have a dedicated fridge for brewing, one I found off of Craigslist for $50.  I also have a Ranco two-way temp switch.  This thermostat is programmable and I just set the temp I want and plug the fridge in the cool side and a 12' wide piece of heat tape, you can get it places that sell reptile equipment, into the heating end.  Then I wrap the heat tape around the carboys and put them in the fridge.  This will hold the fermentation at the perfect temp and you don't have to worry about it.    

Even if you don't have room for a dedicated fermentation fridge it is still worth it to buy the temperature control switch.  You can set the ambient temp of the house a couple of degrees lower than the desired fermentation and wrap the carboy with an electric blanket or set it on a heating pad.  You may have to also tell your wife to put on a sweater.    
                                       

So what do you do while saving the $200 to invest on a temp control system?  There are still ways.  One of the simplest is to put the beer in a basement, a closet in the interior of the house or other cool place, around 65-68 degrees for English Ales.  This will work but your fermenting beer will produce a little heat while at the height of krausen and when fermentation slows it will cool down and the yeast will start to drop out early.  This is fine and you will get good results, just not great results. 

If you want to keep your beer a little cooler than ambient temp try this.  Set the carboy in a basin of water and then put an old T-shirt over it.  The t-shirt will wick the water up and keep the carboy 5 degrees cooler, 10 degrees if you set a fan blowing on it and more if you put ice in the basin.  Set the carboy on a heating pad to warm it up some.  This method works, it is just takes a lot of attention.  Something that helps is taping the probe from an indoor/outdoor thermometer to the side of your carboy so you at least know what the beer is doing.

If you don't have the room for a fridge look up fermentation chambers on the Internet.  I have seen chambers which look like an Armour and sit in the living room to someone who just taped a cardboard box over a mini fridge.  There is a lot of stuff you can do, it just takes a little ingenuity.   Putting the carboy in a tub of water will increase the thermal mass and reduce temp fluctuations, or a room-air conditioner will help.

Brew with the seasons.  Without temp control are are somewhat at the mercy of the seasons but you should still be able to make most ales just using the ambient temp of your house.  Tape a temp probe to the side of your carboy and during deep winter you should be able to make scotch ales, and almost any English beers.  As it gets warmer go to Belgian beers and even in the hottest months you can brew saisons.  Not perfect, but it works.

As if you didn't get the point:  I wish I had figured out temp control years before I did, it would have saved me drinking a lot of mediocre beers.  It will also open a whole new world of beers to you.  You will be able to make crisp summer pilsners, lagers,  Kolshs, California commons and saisons.  All of these beers can be made well with extract and correct temps.

         

I cannot stress how important fermentation facilitation is.  As a brewer you will go through a ton of work developing a perfect recipe and then spend the time and money brewing it.Then you just turn it loose and not care what happens during the ferment?  Respect your beer more than that.  I am even to the point if I meet a homebrewer for the first time, and they don't control their temps, I don't consider them a serious brewer.

I have seen several brewers who look upon brewing as an art and are proud of the fact every batch, even if using the same recipe, is drastically different.  This is just an excuse to cover up laziness.  The art of brewing comes from intentionally manipulating factors to get the exact results you want.