Brewing Beer . . . With Science!

by depotdevoid in Cooking > Homebrew

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Brewing Beer . . . With Science!

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Today I'm going to share two of my favorite things with you:  Science and Beer!

My little brother is the brewmaster at Steelhead Brewery here in Eugene, and is truly a master of his craft.  He's not a graduate of one of those brewing programs you'll find here and there, oh no.  Ted started to learn about brewing by dumping some water, sugar, bread yeast, and root beer extract into a plastic jug in his closet when he was 14, and seeing what happened (it wasn't pretty). 

Over the years he worked at it and worked at it and eventually metamorphosed into the finest brewer I know.  Through study combined with trial and error, he has developed both intuitive and empirical knowledge of the craft. 

Ted came over to my house a while back to help me brew a simple extract based 5 gallon batch of Northwest IPA (my favorite!), and I documented the process.  He took the time to answer some technical questions about what's really going on inside the beer.

Read on to learn not just how to make a great ale, but what's happening on a chemical and biological level, why things are done the way they're done, and have a bit of history thrown in, free of charge.  To start, here's a video of the process, with details in the following steps:



One more thing:  I'm publishing this instructable in tandem with a recipe for simple spent grain bread.  When you're done brewing, use those spent grains to make an amazing, delicious, home baked bread!

Gather Supplies: Basics for Homebrewing

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Brewing beer requires a fairly large amount of equipment.  If you've never brewed before, I highly recommend you find someone who already brews, and see if they'll help you with your first beer and let you use some of their equipment.  That way, you'll find out if you enjoy the process before you make a large cash investment.  What's more, most homebrewers are very enthusiastic about their hobby and love to get someone else on board!

If you have to start from scratch, or you're ready to make that leap and buy your own stuff, there are two good options:

If you want to buy new, find a local homebrewing supply store that you like.  You can buy this stuff online, but having the assistance of someone who really knows the process is invaluable and absolutely worth paying a bit more for--you'll also be supporting local businesses!  Here in Eugene, Falling Sky Homebrew is my first choice.  In most good sized cities, you can find a few options to choose from, so find one you like where you can build a good rapport with the employees--they will be a great source for ideas and information!

If you'd rather buy used or you're low on cash, as I mentioned in my backyard astronomy instructable, this is the kind of hobby people fall in and out of.  Lots of folks have beer brewing supplies they'd really like to get out of the garage, and they'll often part with it for a fraction of what they paid.  Check the classified in the paper and check on craigslist--in fact, take out a wanted ad in craigslist.  Someone will make you a deal!

Here is a list of absolutely must haves:
  • 5 gallon or larger carboy
  • 5 gallon or larger bucket, preferably with a spigot at the bottom
  • Large cooking pot
  • Racking cane, can be as simple as a long glass tube with attached hose, but I recommend spending the extra bucks for an auto siphon, they make certain steps way easier.
  • A large stirring spoon
  • Cooking thermometer with a long probe
  • Carboy brush
  • An airlock for the carboy
  • Sanitizing solution (I like the foaming kind)
  • Hop/grain socks
  • Large funnel
Finally, you'll need something to put the finished product in--classic bottles are cheap and plentiful but require caps and a capper.  Grolsch bottles are totally reusable aside from occasionally replacing the rubber seal and require no extra equipment, but they're much more expensive.  Mini kegs are another good option, but are very expensive to get started with and kind of tricky to carbonate.  Actual kegs and kegerators are another story, and could use an instructable all their own.

Here's another short list, these are nonessential items, but very useful:
  • Wort chiller
  • An extra carboy for secondary fermentation
  • An extra bucket for cleaning
  • Bottle brushes/cleaners

Gather Supplies: Beer Kit

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One of the nice things about shopping at a local homebrew supplier is talking to the staff about the variety of beer kits they're sure to have on hand.  I'm not talking about those brew-a-beer kits they sell at Wal-Mart, rather most homebrew shops will have a folder with recipes and ingredient lists (usually priced out with a discount) on hand.  

The kits will include almost everything you need, grain, malt extract, hops, corn sugar (dextrose), and any special ingredients.  Yeast is usually a separate purchase.  Often, the kit is a clone of a popular beer available in the grocery store.  For our brew, Ted picked out something he knew I'd like--a big Northwest style IPA, heavy on the malts and hops and of course, with a high alcohol content.


Sanitize EVERYTHING!

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Cleanliness is possibly the most important part of brewing a beer.  It's easy for a wild strain of yeast (or some really nasty bacteria) to infect your beer and make it gross, or possibly even explode your bottles!  I wasn't thorough enough when I was kegging this batch, and one of my mini-kegs burst!

So, mix up a batch of sanitizing solution in your bucket and soak everything in it.  Pump it through the siphon.  Pour it into the carboy and shake it around, let it soak for a while (there should be specific instructions on the bottle of sanitizer).

I prefer starsan foaming sanitizer, as you don't have to be as thorough about washing it out of everything--the residue conveniently degrades into a type of sugar that the yeast will consume.

Steeping the Grains

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The first step to brewing is getting the sugars out of your grains.  As we were brewing a beer from extract, we only had a small amount of specialty grains, the rest of the sugars already came in the form of a malt syrup.  In a whole grain brew (which I might post an instructable about some day), you would start with a large amount of grains and extract the sugars from them.  This step begins to create the "wort", which is essentially what beer is before the yeast has had a chance to change the sugar to alcohol.

In your large pot, bring the temperature of a gallon or so of water up to about 170F (about 75C).  Put your grains in a sock (a cotton bag designed for brewing), and put that in the pot, then cover.  The addition of the grains should reduce the overall temperature of the water to around 150F (about 65C), where it needs to sit for around 30 minutes.

At this point, the hot water is allowing the amylase enzymes already present in the grains to start breaking down the starches in the grains into fermentable sugars.  It doesn't really take all 30 minutes to do the job, but that extra time allows the water to really permeate the grain sock and break down as much of the starch as possible.

Sparging the Grains

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Sparging is when you wash your grains with hot water to get as many of the fermentable sugars as possible into the wort.  With an all grain batch, you would want to use 150F (about 65C) water, but with a simple extract batch like this you don't have to be as thorough.  Hot water from the tap should be fine, I have mine turned down to 130F (about 55C).

If you don't have a wort chiller available (as I didn't), it's a good idea just to do a partial boil.  In a full boil, your wort will contain all the water you are later going to ferment, but without a chiller that would take way too long to cool down.  Some of the oils from the hops would degrade and you would lose some of your aroma.  When you're sparging the grains, keep the water turned low and limit how much water gets into the wort.

Place a colander at the top of the brewing pot and put the grain bag inside of it.  Gently sparge the grains with hot water until they run clean.

Set aside the leftover grain, you can use it to make bread later on!

Bringing the Wort Up to Temperature (and History!)

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Once the grains have been sparged, pour in the malt extract, return the pot to the stove, and heat it back up.  You'll need to stir pretty constantly to make sure the wort doesn't scorch or begin to caramelize on the bottom.

At this point, we also make the first wort addition of hops.  Hops, or specifically the female flower of the hops plant, is used as a bittering and flavoring agent in most types of beer.  Hops also have some natural antiseptic properties which help to stave off infection of the beer by wild yeasts and bacteria.  

Add the hops to a sock and drop them in the heating mixture.  This addition is mostly for flavor, though it does add some bitterness.

Keep stirring, and wait for the "Hot break," when the wort begins to boil!

While we waited, I asked Ted to talk about the history of the India Pale Ale:



The Boil

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Once the wort starts to boil, a countdown begins.  Depending on the recipe, you will be boiling the wort for 60, 75, or 90 minutes, we boiled ours for 60 minutes.  Immediately after it boils, it's time for the bittering addition of hops, put them in a hop sock and drop it in.

The hops added this early will have their oils mostly broken down by the end of the boil.  This will destroy their aromatic properties, but create the bitter flavors that counterbalance the naturally sweet beer flavor.

At fifteen minutes from the end of the boil, the next hop sock is added.  This addition is for hop flavor, rather than bitterness.  The oils and flavor characteristics of the hops will have time to be extracted from the flowers, but only partially be broken down, adding the hoppy flavor to the beer.

The final hop addition happens just five minutes from the end of the boil.  The hop oils won't be broken down at all, and add only aroma to the beer.

Besides adding the various hops characteristics to the beer, the boil also serves to evaporate a number of unpleasant chemicals from the wort, such as dimethyl sulfide.  Dimethyl sulfide, or DMS, rather unpleasantly adds a burnt plastic taste to beer.

At sixty minutes of boiling, it's time to remove the brewing pot and start chilling it--this is known as the "Cold break".

Chilling the Wort

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This is the point at which a wort chiller would be useful.

Without one, simply plug one side of your sink, put the pot inside, and fill it up with cold water and ice.

Stir the wort and constantly monitor the temperature.  Depending on the yeast and type of beer you are aiming for a pretty specific temperature.  The yeast we used is a special British ale yeast used by the Steelhead Brewery here in Eugene, and we needed the wort at 70F (about 20C) for optimum fermentation.  At too low of a temperature yeast are inactive, and at too high of a temperature they die.

To further speed the cooling of the wort, you can sparge the hops with cool water--my brewing pot conveniently has markings on the inside for capacity, so we were also able to add enough water at this time to bring it up to about 4 1/2 gallons.


Pitching the Yeast

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Once the desired temperature is reached, it's time to pitch the yeast.

Yeast are single celled organisms in the fungi kingdom.  The types of brewer's yeasts used in making beer and other alcoholic beverages do one important thing:  they consume sugar and excrete alcohol and carbon dioxide.  Yes, you are drinking fungus pee, and those bubbles in bottle conditioned beer are in fact yeast farts.

Pour the wort into your sanitized carboy.  When it's all in there, add the yeast and gently shake it around until it's been thoroughly mixed.  Don't fill the carboy all the way up to the top, leave some room for the yeast to work and to dry hop later on.

Primary Fermentation

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Now, the waiting begins.

Secure the top of the carboy with an airlock.  Remember, if you left enough room at the top you won't have to worry about blowoff, the beer will foam up, but if there's enough empty room in the carboy there shouldn't be any coming out of the airlock.

Put the carboy in a dark place, somewhere not too hot and not too cold.  I use a closet under the stairs, surrounded by lots of blankets.  Make sure you put the carboy on a towel, just in case something goes wrong and it blows off a bunch of foam!

Let it sit for 1-2 weeks for most of the yeast to eat and multiply, quickly turning the sugars in the wort alcoholic and then dying and sinking to the bottom of the carboy.  This primary fermentation period is by far the most active period for the yeast.

Dry Hopping

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Dry hopping is a simple process.  About an ounce of the hops were saved in my freezer.  When time came to dry hop, we simply removed the airlock and stuffed the hops into the carboy, then topped off the carboy with fresh water.  The airlock was returned to the carboy, and we let it sit for another 1-2 weeks.

A lot of people will take this opportunity to put their beer into secondary fermentation.  That simply involves racking the beer into a fresh carboy, helping to clarify the final product.  It's not strictly required, but if you worry about your homebrew being a bit chunky, that's one way to avoid it.

The purpose of dry hopping a beer is to add a very strong hoppy aroma to it.  These hops add little in the way of flavor and no bitterness, but having these fresh hops sit on top of the beer for another couple of weeks adds an incredibly strong smell of hops to the beer, creating the full Northwest IPA experience.

Kegging or Bottling

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After the dry hopping and secondary fermentation, your beer is essentially ready, except for one thing:  it's flat!

If you've got an expensive force carbonation rig, or if you're using a keg system, you can start drinking your beer right away.  However, most homebrewers will need to bottle condition their beer.

Basically, we add some corn sugar to the beer before bottling it, to restart the yeast.  With the beer under pressure in a mini keg or a bottle, the carbon dioxide produced by the yeast will be forced into solution, creating those carbon dioxide bubbles we all know and love!

The first step is to sanitize all your equipment again--you can't be too careful!  I must have made a mistake with one of the kegs, it got an infection, swelled up and burst!

When done, heat up a little water and about 1/2 a cup of corn sugar on the stove, stirring until it's completely dissolved.  Pour that mixture into your bucket (preferably with a spigot at the bottom).

In a process called racking, use the siphon to move the beer from the carboy to the racking bucket, doing your best to leave behind the dead yeast at the bottom and the mess of hops at the top.  

Once it's all in the bucket, it's time to put the beer into the final receptacles.  Using a hose attached to the spigot on your bucket (or the siphon again, if you don't have a spigot) simply fill each bottle or keg as high as you can.  Make sure you're doing this on a towel, I always make a mess.

One reason I like grolsch bottles and mini kegs is the ease of capping them.  With the bottles, you simply use the wire bail on top to seal them.  The kegs have a bung at the top that presses in.  If you're using standard bottles, you will need bottle caps and a capping tool.  Simply heat up the caps and use the capping tool to press each one onto a bottle.

Finally, return the bottles and kegs to the closet and give them another week or two to carbonate.

Here's a quick video of the process:




Enjoying

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Put the bottles into the fridge the night before you plan on drinking them, and put the kegs in two nights before--you want to make sure your beer is well chilled!

Make sure to enjoy with a friend!  Don't drink directly from the bottle, pour it into a glass, and make sure to leave the last bit at the bottom of the bottle, as there's usually a bit of dead yeast down there.

Also, rinse out your bottles right away, if you plan on reusing them.  It's really easy to rinse the yeast out now, if you let it sit it will cake on and present a real problem later.

Final Thoughts

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I love beer.  I love science.  I love hanging out with people and drinking beer, while talking about science.  I had a lot of fun working on this instructable, though the write up has been challenging--the process of crafting a beer takes so long (and involves drinking beer), it becomes difficult to recall all the details later on.  

Special thanks on this instructable to my little brother Ted for helping out.  His expertise is entirely responsible for the fine Northwest IPA we crafted, and for laying all this knowledge down.  If you're ever in Eugene, make sure to stop by the Steelhead and try one of his beers.  You won't regret it!

Thank you for reading this long and involved instructable!  Please leave a comment, rating, favorite, and subscribe, I love feedback and I've always got more coming!  Also, if you brew your own beer with help from these instructions, post some pictures in the comments below and I'll send you a digital patch and a three month pro membership!