Brew Day: Copper Amber Ale

One of my first craft beers I tried when I moved to Charlotte was an Olde Mecklenburg (OMB) Copper Ale. It was an easy-drinking beer that helped me ease into the rabbit hole I call craft beer. This used to be my go-to beer whenever we went out because it wasn’t too “knock your teeth out” hoppy and was incredibly refreshing. I was excited to find out that one of my friends requested this particular style because it was his favorite also.

Full disclaimer: I'm an engineer and get 
geeked up about the science of things...

Yeast Starter:

According to my recipe via BeerSmith, Copper Ale v1, my yield will be 11 gallons at 1.051 SG. So using my handy-dandy yeast pitch calculator:

12 gallons of wort (I will lose some from yeast in fermentation) at 1.051 SG: I will need approximately 430 billion yeast cells.

Using 2 vials of yeast at ~100 billion each, I would need a yeast starter of at least 2 liters in 1.036 SG of wort. This should provide 503 billion cells (C. White Stir Plate  growth model) with a pitch rate of 0.88M cells / mL / ºP. I like to make a little extra so I ended up making a starter with 4 liters of 1.036 wort to yield 616 billion cells.

I used WLP002 English Ale Yeast – I know, I know this is an American Ale… Why did I chose an English Ale. My go-to WLP001 California Ale Yeast was out at my homebrew store (I guess it’s very popular!?) so I had to settle with this. I’ve used this before with excellent results and the difference is slightly noticeable with a little less clean taste.

Brew Day:

Asst. Brewer Sarah

Today I invited residents of my apartment complex to come watch me brew. Because of the long process (being that it takes 6 hours and all), not many stayed, but I welcome any chance I get to share this exciting hobby of mine.

Residents trying to stay enthused about enzymes in action!

As I explained in my last post, Jitterbug Coffee Stout, my setup is a modified HERMS system where I circulate my wort through a hot liquor tank (HLT) and then back into the mash tun (MT). I originally learned this method from The Electric Brewery who has a step by step brew day explanation page. I prefer this method from the single step mash one because of consistency and repeatability.

Anyways, I heated up 6.875 gallons (1.25 L/ lb. of grain) of strike water to 170º F and circulated it into the 10 gallon cooler I have modified to make a MT. Then I dough’d in to give me a mashing temperature of 155ºF — A little high, but it is within my range to target the alpha-amylase enzymes and let them go to work converting my starches to sweet, sweet wort. I also love this smell as it smell as it smells like oatmeal like I would have as a kid.

I need a new thermometer

Grain Bill:

The BJCP guidelines on this style call for this to have a slight malty taste so I added a little bit of Munich Malt and Caramel Crystal Malt. The Chocolate malt is there to give it more of the burnt orange color that is indicative of this style, but there it not enough to contribute much if any flavor. Despite its name, chocolate malt does not give any chocolate taste to the beer, but more of a burnt, smokey taste. It also says that the International Bitterness Units, or IBU, should be moderate to high so I targeted around 30 IBUs.

  1.   20 lbs. of Pale Malt (2.0 SRM)
  2.   1 lbs. of Munich Malt (20 SRM)
  3.   0.75 lbs. of Caramel/Crystal Malt – 120L (120 SRM)
  4.   0.5 lbs. of Chocolate Malt (350 SRM)
Side note: SRM stands for Standard Reference Method 
which is used by modern brewers to measure the color 
of the beer. The higher the number the darker the beer.

After mashing for about 15 minutes I turned on the pump and started circulating my wort through the HLT. This acts as a Vorlauf method to help clarify the beer. In another 20 minutes, I had achieved conversion where my starches were converted into sugar — Simple science proves that at a hotter temperature molecules move faster… The same goes with enzymes and how fast they work.

Fly Sparging:

I meant to raise the temperature of the mash to 167ºF to denature the enzymes, but I forgot. It won’t be the end all be all,  just my efficiency will suffer a little for it. I was teaching a brew class to the residents of my apartment complex and I guess I got distracted.

Mash Out:

Utilizing the fly sparge method (replenishing the water back into the MT as it’s being drained) I collected 12 gallons of wort at 1.044 SG over a period of about 45 minutes. It’s often debated whether it’s worth it to sparge slowly or fast and I often find myself in between both parties.

View from the refractometer

Plugging this into a brewhouse efficiency calculator the total yield if at 100% efficiency would have been 1.068. At 1.044, my efficiency was at 65%… Not my worse, but not my best.

The recipe calls for me to have 13.75 gallons at 1.044SG so I missed my mark. This could’ve been for a couple of reasons, one of them being that I forgot to mash out. using BeerSmith’s dilution tool I calculated that if I added 1.75 gallons, I would achieve 13.75 gallons at 1.038 SG.

I love the etched markings inside the kettle

After collecting the correct amount of wort based off my boil off calculation of about 12% (it varies depending on ambient conditions, but usually hovers around there, I place the kettle on the turkey fryer and flame on!

Usually it takes about 20 minutes for the turkey fryer to raise the temperature to boiling… About 15 minutes in, I have to watch closely to prevent a boil over and loss of sweet wort. The general rule of thumb is that you want your kettle to be double the yield you’re making… simple math: 10 gallons x 2 = 20 gallons. Though before I made this purchase I was making 5 gallon batches in a 7 gallon kettle (see below)… boil over was inevitable no matter how hard I tried.

5 gallon boil in my 7 gallon kettle = No fun

 

Remember that it’s important to have a good, vigorous boil in order to drive off unwanted flavors such as Dimethyl Sulfides (DMS) and to fully isomerize your hops. Also, you want to leave your kettle uncovered because the condensation dripping from the lid contributes to off flavors as well.

American Copper Amber Ale Boil Additions:

  1. Chinook (13.0 % α) @ 0 minutes
  2. Williamette (5.0% α)  @ 20 minutes
  3. 2 capsules of White Labs Servomyces (Yeast Nutrient)
  4. 2 tablets, crushed of Whirlflock (fining Agent)*
  5. Williamette (5.0% α)

*Whirfloc Tablet is a finish agent, like Irish Moss, coagulates and attaches to the unwanted proteins within the wort to help clarify the beer.

Hops added at different times contribute different flavors and aromas to the beer. When hops are added to the beginning, they are fully isomerized and contribute to the overall bitterness. If added at the end, then they contribute more to the aroma. Depending on your wants and the style of the beer, hop schedules can vary from one addition to adding it throughout with 5 minute intervals. There has been much debate whether this is necessary, but some brewers swear by it saying it adds complexity and multiple layers to the flavor.

Chilling and Adding to Carboys:

After the 60 minute boil (standard boil time) it is time to chill the beer… The faster, the better! This is because of the “Cold Break” where the proteins within the wort are thermally shocked and coagulate out of the beer resulting in a clearer beer. There are types of beers who’s style is supposed to be cloudy, but in most it is not preferred. There is also something called “chill haze” where, when cold, the final product is cloudy. When the cold brew heats up a little, the haze is gone.

      Counterflow Wort Chiller

Essentially, this is an heat exchanger where the hot wort goes in hot and comes out cold and the cold water goes in cold and comes out hot. This is achieved by the two fluids flowing in counter flows (hence the name… get it?)

Once it reaches the carboy, it’ll be around 70ºF – The perfect pitching temperature for yeast. Side Note: wort is also a breeding ground for other bacteria and air-borne particles floating about… For this reason it is important to pitch your yeast as fast as possible.

Filling up the carboys

As you can see, the wort is coming out of the hose as a nice amber/ copper color… Amber Copper Ale (it’s coming together now)

My final gravity into the carboy was a little lower than expected. Most likely because I forgot to raise the mash temperature up to 167ºF which would halt all enzyme activity.

Gravity reading at 1.046 SG

The final yield was 12 gallons @ 1.046 SG. I will lose some during fermentation to give me about 10.5-11 gallons of beer to carbonate.

Fermentation:

I am going to use WLP002 English Ale Yeast as you can read from my yeast starter section I should, theoretically, have around 600 billion cells. I overshoot just for peace of mind. After about 24-36 hours on the stir plate, I chill the container and let the yeast settle. Because you don’t want to add necessary flavors to the beer, I decant out the liquid that does not contain yeast (it flocculates out and to the bottom. Most experts (or beer nerds) say that you shouldn’t add more than 5% of your yields volume… That means I shouldn’t add more than 0.25 gallons of starter liquid (not meaning the yeast, but the by product alcohol – I’m actually pouring alcohol down the drain :/)

Yeast starter after chilling

As you can see, there is a thin white line above the trub (pronounced troob) and the suspended liquid… This is healthy yeast cells and what needs to be targeted. I decant off and pitch the healthy yeast, trying to be as equal as possible, between the two carboys… Let the fermentation begin!

24 hours update:

After I pitched the yeast I typically check on it after about 12-24 hours to see if the airlock is okay and it’s having a healthy, vigorous fermentation. To my surprise, and dismay, it was fermenting so strong that it popped off the airlock! I don’t know how long it was off for, but it should have any adverse effect on it. It’s good to know that the little monsters are off and healthy!

Airlock popped off!

Brew Day: Jitterbug Coffee Stout

Brewing a coffee stout today from request of a neighbor. I try to use local resources as much as possible, so I’ll be using the a cold brew from Smelly Cat Coffee House in my NoDa Neighborhood and cocoa nibs and vanilla beans from Savory Spice in South End.

Full disclaimer: I'm an engineer and get 
geeked up about the science of things...

Created a yeast starter:

The coffee stout final yield will be 11 gallons at 1.062 SG. Using the pitching rate for an ale at 0.32 million cells / mL / ºP and according to Brewer’s Friend  I will need approximately 475 billion (yes, with a B) yeast cells. Now there are hundreds of different types of yeasts to chose from… Today I chose an WLP004 Irish Ale Yeast to help me replicate the infamous Guiness Irish Stout. Each yeast pack has about 100 billion cells (if not more) in them. Either, I could buy 5 packs at about $7/per, or create a yeast culture… I chose the cheaper option. With 2 packs of yeast, I made a 4L starter at 1.036 with a stir plate to give me a total of 626 Billion cells (I often over estimate to give me a nice safety factor.)

Brew day:

My setup is a HERMS (Heat Exchanger Recirculating Mash System) — I’ll link to my equipment later in a tab. In this setup, I utilize a Hot Liquor Tank (HLT) – No there’s not liquor in there! A brew day with diagrams can be seen fully at The Electric Brewery Page. I chose this system because I wanted it to be repeatable and I found it hard with other methods.

My recipe calls to heat up my initial strike water to 167°F.  I use Deer Park Spring water due to the fact that city water often has chlorine in it which can be removed with chemical agents, but ‘ain’t no one got time for that‘. I made a couple of brews with tap water and noticed that I was often having an off-flavor in my beers that only started when I switched.

Mashing:

But I digress, to start I heated 6.875 gallons of strike water (to receive a thickness of 1.25 qts/ pound of grains) to 167°F.

Coffee Stout - Initial Strike Water
Circulating the strike water into the mash tun
Dough in:

After the water has been transferred, dough’d-in the 22 lbs. of grains to reach a mashing temperature of 152°F.  Rule of thumb is you want your strike water to be about 14ºF higher than what you want your mash temperature to be.

Coffee Stout - Doughed in
Doughing in the grains after adding the strike water

Ideally the mash pH needs to be a 5.2 in order to achieve the highest efficiency and taste. One of which is water chemistry. Here, I’m trying to target the alpha-amylase enzymes to leave me that thicker, almost chewy beer that is indicative of a stout. For more about mashing and targeting certain enzymes during mashing, byo.com has a very good write up – In the future I might try using a step mash method for the dry stout profile.

Grain Bill:

To make a coffee  stout I used heavier darker malts to add the almost burnt taste. Side Note, I am using DME because my limiting factor is a 10 gallon Cooler as a mash tun with a max grain capacity of ~24 lbs depending on the water/grain ratio. I also wanted a thicker body so I added some unmodified malts:

1.  12.5 lbs of Pale Malt, Maris Otter (3.0 SRM)

2. 5 lbs. Extra Light DME

3. 4 lbs. Caramel / Crystal Malt 40L (40 SRM)

4. 2 lbs of Flaked Barley (1.7 SRM)

5. 2 lbs. of Carafa III (525 SRM)

6. 1.5 lbs. of Flaked Oats (1 SRM)

NOTE: SRM is a rating of color. Explanation can be found here.

SIDE NOTE: Homebrewing is a type of rabbit hole. 
You can make good beer using minimal techniques, 
but to go into making great beer, there are multiple 
considerations.... One of which is water chemistry. 
Bru'n water has a very good and elaborate write up 
of it here and has excel spreadsheet to enter in values 
of your water profile. I tend to 5.2 pH stabilizer. 
While there is an on going debate to whether it helps 
or not, I've produced very good beers while using it. 
Those deep into the water chemistry will try to match 
water profiles from all over the world for their 
specific beer types... Such as Dublin for an Irish 
Stout or London for a Brown Ale.

After mashing for about 15 minutes, I turned on the sump pump to circulate the wort through my coil submerged in a HLT to help control the temperature. This also acts a vourlaufing, or draining and recirculating, the wort to help clarifying it. Essentially the grain bed acts as a sieve through which the water can travel. As the wort circulates, the grain bed settles and the wort is clarified.

HERMS Wort Circulation
Circulation Wort through HLT

After about another 30 minutes, we have conversion! For those who remember 6th grade science class, iodine in the presence of starch within an aqueous solution changes color to a deep purple/blue color.  This happens when the tri-iodide and penta-iodide ions formed are linear and slip inside the helix of the amylose (a form of start). The iodine test, in turn, changes the wavelength of light that is absorbed – resulting in a intense color purple. Science! Keep in mind that darker beers, like my coffee stout, it may be hard to tell whether there is a color change.

Coffee Stout - Conversion
Iodine Starch Conversion
Sparging:

After conversion, I raise the temperature of the mash tun to 167°F to denature the enzymes. Then I rearranged my pump setup so that I can sparge and drain the mash tun into the boil kettle. This process, in order to achieve the maximum brewhouse efficiency (each grain has a sugar potential for maximum sugar conversion. Depending on your process, most achieve anywhere from 65% to even 90%.) Beer Smith does an excellent job listing the potentials of all grains that a homebrewer might use. The gif below shows good confirmation that the coffee stout will be a good color.

Coffee Stout - Sparging the Mash
Mash out:

The next step is to sparge once the mash temperature reaches the 167°F. I utilize the fly sparge technique where I slowly replace the wort with water as I drain the sweet wort (wort that has yet to have been boiled, or yeast added) This process, ideally, should take close to an hour and in theory, the water washes the sugars from the grains as the drains through false bottom. I drain the wort until the runnings have reached gravity of 1.010 – at which point there’s a chance of polyphenols, or tannis (adds unwated off flavors and contributes to chill haze)

At the end, I collected 10.5 gallons at 1.047 SG – Missed by 0.005 points. Due to boil-off, I need about 13.5 gallons for a full 60 minute boil (I have found that I lose about 1.5 gallons per hour.) I added 3 gallons to reach the yield to give me a diluted pre-boil wort of 1.036.

Gravity: Specific Gravity is measured against pure water
at 60°F which will measure 1.000 using a hydrometer. 
For smaller batches a refractometer is preferred due to 
the fact you require a lot less wort - But can't be used 
after fermentation... and in turn more beer :). When 
submerged into wort, the gravity reading tells brewers how 
much sugars are present within the liquid. As the yeast 
works, there will be less and less sugars present (and more alcohol ;)) in 
the solution until there is very little left. The 
difference is how brewers can tell the alcohol content 
of the beer. Hence, the higher the original SG, the 
higher the alcohol content.
Boil:

Add the pot on the turkey fryer and raise to a boil being careful of a boil over — Once the wort comes to boiling temperatures, protein from the aqueous solution coagulates and rises in the surface in a foam-type substance. The easiest way of preventing boil-over is to reduce heat and stir. It is also important to have a vigorous boil to drive off unwanted flavors and to fully isomerize your hop oils.

Coffee Stout - Boil

Coffee Stout Boil Additions:

1.  1.0 oz. of Northern Brewer Hops (8.50% α) @ 0 minutes

2. 5 lbs. of Extra light DME*

3. 2.0 oz. of Northern Brewer (8.50% α) @ 30 minutes

4. 1.0 oz. of Nugget (14.0% α) @ 30 minutes

5. 2.0 oz. of East Kent Goldings (5.6% α) @ 15 minutes

6. 2 tabs White Labs Servomyces Yeast Nutrients.

7. 2 tablets, crushed of Whirfloc Tablets† (fining agents)

*DME is Dried Malt Extract – DME used for extract brewers to bypass the mash step and go straight to the boil. Used with a lot of beginner brewers.

†Whirfloc Tablet is a finish agent, like Irish Moss, coagulates and attaches to the unwanted proteins within the wort to help clarify the beer.

Chilling and adding to Carboys:

After the 60 minute boil is complete, it is important to chill the beer to pitching temperatures as soon as possible. This is called a ‘cold break’ in which it helps coagulate the proteins so you can separate them before transferring to the carboys. I use a combination of a counterflow wort chiller with a ice bucket to quickly chill the wort as fast as I can pump it out.

Counterflow Chiller

A counterflow chiller acts as an heat exchanger where the 2 fluids, one hot and one cold, flow in 2 separate direction in turbulent conditions. Ideally, this will intake ice cold water and boiling wort and output them as the others starting temperature. Of course there will be some loss, but this is the more efficient way.

Coffee Stout - Chilling Wort
The Wort goes from boiling to 70* within seconds

 

The wort is added to the carboys at about 70°F – Keep in mind it goes from 212ºF to 70°F in less than a minute… As soon as it is full I top it off with a SANITIZED bung and a air stopper (Sanitation is VERY important at this point due to room-temperature sweet liquid is a safe haven for bacteria and unwanted airborne yeast. I like using StarSan for all my sanitation needs )

Coffee Stout - Filling the Carboys
FIlling up the Carboys

My final yield was 12 gallons at 1.060, 0.003 points below the projected gravity.

Pitching the Yeast:

After the wort is in the carboys and capped, I took the yeast starter that I created 24 hours before cooled it so that I can decant it. This is a popular method to use due to the fact that with large starters, you’re adding a large percentage of liquid to the beer which, in turn, can alter the flavor of it. When you decant it, you cool the yeast so the yeast collects at the bottom. You then pour the excess liquid from the top and you’re left with pure yeast. From the picture the more viable yeast is the thin white layer on top, but the rest is usable.

Fermentation:

I chose to use sevomyces as it receives better results than with typical yeast nutrient with excellent results. Nutrients are needed for the overall health of yeast, this is thoroughly noted in Chris White’s of White Labs book ‘Yeast’ (Which I highly recommend.) The nutrients present alone in the wort is enough for making beer,  but others such as zinc is best for overall yeast health. Servomyces provides this for the yeast along with others to provide a healthy fermentation. I have always had vigorous fermentation within 6-10 hours or pitching using this supplement. 2-3 weeks later, a new coffee stout is born!

Coffee Stout - Fermentation

The coffee stout is fermenting well and in about 10 days I will check the gravity to see if it is close to the final gravity of the beer.

To Be continued…

I know I know…. I said I was making a coffee stout…. Where’s the coffee come into place??? To make the stout a coffee flavored ones I’ll be adding the cold-brewed coffee, cocoa nibs, and the vanilla beans in the secondary… Stay Tuned!

I hope you enjoyed reading. Stay tuned as I post the progress of this coffee stout to the final drinkable product. Please leave comments below.

Luke