Avoiding Oxygen When Kegging (CO2 Transfer Process)

There are many advantages in homebrewing that are simply not feasible in a commercial brewing environment. Homebrewers can take liberties in flavor and recipe experimentation where the worst thing that happens is that we end up with 5 gallons of beer that we have to dump because it makes taste testers vomit when they smell it (yeah, that's right, I'm talking to you, Berliner Weisse attempt #1). Now, let me be clear, I in no way mean to downplay the shitty experience of losing a batch of beer, but let's face it, the only thing being lost is a small amount of money, wasted time, and a healthy dose of pride. When a small craft brewery has to dump a batch of beer, it's thousands of dollars lost, unfulfilled orders, and empty tap handles to sell to thirsty, loyal customers.  

On the flipside, and maybe not earth shattering news, the commercial brewing environment has many advantages that are cost and space prohibitive for homebrewers. Commercial breweries have more resources and specialized equipment designed to automate and control various aspects of the beer making process. One area on the cold side of the equation that commercial breweries devote a considerable amount of engineering efforts towards is keeping oxygen out of freshly crafted beer.

A small amount of oxidation is appropriate for some beer styles, but most beers benefit from reducing as much as possible the amount of dissolved oxygen that makes its way into beer after fermentation is complete. In pre-fermented wort, oxygen is the giver of life. In post-fermented beer, oxygen reduces shelf stability, causes off flavors reminiscent of wet cardboard and sherry, degrades hop aroma through degradation of terpenoid and sesquiterpenoid compounds reacting with oxygen in the headspace of the bottle, and can cause diacetyl development through oxidation of diacetyl precursors present in the beer.

Carboy to Keg CO2 Transfer Process:

A few commenters on a recent Instagram post asked about my fermentor to keg transfer process. This blog post is me finally making good on my word to share how I transfer beer from fermentor to keg in a CO2 environment. A carboy with a racking cane is used in this setup, but the same technique can be used with just about any fermentation or conditioning vessel.

We are starting with a working assumption that all parts being used are cleaned and sanitized at the time of use, and that proper sanitation processes are followed along the way (e.g. corny quick disconnects are sprayed with sanitizer before connecting, etc.). I have settled on using ¼” ID thick-walled (½” OD) silicone tubing because I like being able to boil it for sanitation/sterilization, and it forms a quite secure connection with ⅜” fittings without the use of worm clamps (silicone is more compliant than vinyl, so in my experience a smaller diameter works better). If you use PVC tubing or will be using worm clamps, consider using ⅜” ID tubing. You may need to experiment to get the right size for your setup. I have some pictures included with alternative connections using PVC tubing and Luer Lock fittings. This process isn't set in stone and can be adapted/modified to work with any system.

All items in the wallpaper tray awaiting sanitizer

Items needed:

1. CO2 tank with low pressure regulator (not pictured). If your regulator is not hand adjustable, you will want a screw driver to adjust the flow. If you are kegging your beer, I’m assuming this is something you already have along with your keg.
2. Kent Systems female shut-off quick disconnect attached to the CO2 line (stops flow of air when disconnected). I link to a ¼” barb fitting because my system has that size tubing for the utility line, but they can be found in various barb sizes.
3. A few feet of ¼” ID (½” OD) silicone CO2 tubing for the CO2 line with a ⅜” barb male Kent Systems quick disconnect on one end. Use whatever diameter tubing you find gives you a secure connection around the carboy cap and works with your quick disconnect setup. You can use just a small piece of tubing if the main tubing coming off of your CO2 tank is long enough and doesn't weigh down or pull on the carboy cap.
4. ⅜” racking cane (either stainless steel or plastic should work).
5. Carboy cap  - two sizes are sold, so be sure to get the appropriate size for your carboy.
6. A few feet of ¼” ID (½” OD) silicone transfer tubing, or ⅜” vinyl tubing with worm clamps.
7. Ball lock beverage out quick disconnect with ¼” male flare post (because we are using quite stretchy ¼” ID silicone tubing, it’s easier to use the disconnects with flare fittings which can be adapted to ⅜” barbs, which work well with this tubing).
8. ⅜” barb to ¼” female flare swivel nut fitting (for corny quick disconnect).
9. Racking cane filter - This keeps trub, hops and/or fruit from traveling up the racking cane and clogging your flow at the ball lock quick disconnect.
10. Wallpaper tray - not required, but very helpful for filling with Star San and sanitizing everything together while assembled (and for general cleaning use around the home brewery).
11. ¼” or adjustable wrench for pre assembling the corny quick disconnect and female flare swivel nut.

Steps:

1. Pre sanitize kegs and fill with C02 (purge and fill 2-3 times to eliminate as much O2 as possible). Leave pressurized to test the seals.
2. Crash cool for 48 hours or more, depending on flocculation characteristics of the yeast, then allow to warm up a couple of degrees before transfer to remove negative pressure inside the carboy (negative pressure will suck in ambient air when removing the airlock or blowoff tube).
3. Assemble racking cane(4), carboy cap(5), and racking cane filter(9), and place inside the carboy with the bottom of the racking cane a little above any solids at the bottom of the carboy.
4. Assemble the transfer tubing(6) and quick disconnect(7)(8).
5. With the regulator pressure all the way off and the shut off valve open, attach the CO2 tubing(3) to the main CO2 tank via the Kent quick disconnects(2)(3) to allow the pressurized CO2 in the main line to depressurize while purging the transfer line at the same time. Then close the shut off valve.
6. Attach the open end of the CO2 transfer line(3) to the small opening of the carboy cap(5). You will want to push the tubing at least ⅝” (or more if you can do it) onto the cap to ensure a good connection to prevent it from popping off while transferring under pressure.
7. Purge most of the CO2 out of the keg with the pressure relief valve, then connect the beer transfer tubing assembly to the liquid out of the keg to ensure there is no sanitizer left inside the keg, to purge the transfer line with CO2, and to make sure that no CO2 from the keg is pushed into the racking cane(4) (which could disturb the sediment in the carboy).
8. If your pressure relief valve can be left open by lifting and turning a half turn, leave it open now.
9. Attach the open end of the beer transfer tubing(6) to the racking cane(4). Make sure it is ¾” up the racking cane arm to ensure a secure fit. With my setup, no worm clamp is needed, but using one is good insurance and recommended if the tubing isn’t a very secure fit (if the line pops off you’re going to have a huge mess on your hands).
10. Open the shut-off valve on the CO2 regulator and then slowly turn the regulator pressure up until you hear it begin to transfer CO2. You should see beer begin to flow from the dip tube through the transfer line and into the keg at this point. If you have the type of pressure relief valve that does not stay open with a ¼ turn, you’ll need to lift it every 10-20 seconds to ensure beer keeps transferring (I got tired of that and have since replaced all of my pressure relief valves with this type that will stay open.
11. Assuming you cold crashed, you can just watch the rising condensation on the keg to see where the beer level is at, and disconnect the keg quick disconnect when it gets to the correct level (closing the pressure relief valve a few seconds before disconnecting the quick disconnect).
12. I've found that carboy caps are not always the most secure fit, especially on the 6 gallon carboys. There have been a few times that the cap has popped off during transfer (particularly if I am rushed and transferring with a little higher pressure). While this is usually more alarming than it is a problem, it can disrupt the flow of beer and disturb sediment at the bottom of the carboy. To prevent this, keep your hand around the cap to hold it down on the mouth of the carboy. You’ll hear some CO2 leaking around the cap, so just hold it in such a way that less CO2 escapes.
13. Shut off the CO2 flow and depressurize the carboy by disconnecting the Kent quick disconnects.
14. Reconnect your corny gas quick disconnect to your CO2 tank (it’s easy to swap out if you have another Kent quick disconnect), turn up the pressure a bit (8-10 PSI, but never more than the pressure the keg will be hooked up to for carbonation, unless you want beer up your gas line or have ball lock quick disconnects with check valves), and then purge the filled keg a few times with CO2 (fill with CO2, pull the pressure relief valve, repeat).
15. Connect the keg immediately to the CO2 line you will be carbonating it with, if possible. Cornelius kegs lids sometimes leak air without positive CO2 pressure to hold them in place, which in turn would allow ambient air to creep in.

Note that in some images you will see additional Luer Lock connections (which I use to quickly switch out various connection types).

Have some questions, criticisms, thoughts or suggestions? Feel free to post them in the comments.

Saison with Strawberry and Apricot (Fantôme-ish)

Ask any beer geek, "what got you so into beer?" and you're likely going to hear an answer involving aha moments of when particular beers made a profound impression in that person's life. In my story, one of those moments was when I had Fantôme Saison for the first time. I can distinctly remember the smell of wild strawberries and other nondescript stone fruit busting out of the glass. Once I got past those initial characteristics, spices, earth, and a slight funk were also present. On the palate, those same flavors carried through, but were accompanied by some lactic tartness.

I have been told by people who have asked him, Dany Prignon asserts that there is no fruit in Fantôme Saison. All of the aromatics apparently come from the interplay of malt, yeast and a proprietary blend of spices.

Researching online for a recipe from someone who was familiar with the original beer and who could provide input on their clone attempt, brought me to this thread at Northern Brewer. Very few changes were made to the original recipe. I substituted Hallertauer for Tettananger and used powdered instead of crushed coriander (and less of it). The goal was to make a beer with a similar sensory profile to Fantôme Saison, not to clone it.

At the time that I brewed this beer, I had yet to find a yeast that throws off strawberry esters (until Dmitri of BK Yeast sent me his 2007 Cantillon Iris C2 strain). To achieve that character, frozen strawberries were used because I could not find a strawberry juice that was actually juice from strawberries, and because the frozen strawberries were picked ripe and then frozen, rather than picked green and ripened on the shelf (I couldn't find any freshly picked strawberries at the time that were worth writing home about). Apricot juice (which contained other juices, such as grape juice) from my local health food store was used for the apricot character. A pure, unadulterated apricot juice could not be found.

Fantome inspired

Saison

 

Type: All Grain	Date: 5/13/2012
Batch Size: 11.50 gal	Brewer: Luke Hagenbach
Boil Size: 13.98 gal
Boil Time: 60 min	Equipment: Blichmann 20 Gal brewing system
Brewhouse Efficiency: 70.00
Ingredients
Amount Item Type % or IBU 11.50 gal Denver-ish water Water 20.25 lb Pilsner (2 Row) Bel (2.0 SRM) Grain 61.16 % 3.34 lb Munich Malt (9.0 SRM) Grain 10.08 % 1.02 lb Acid Malt (3.0 SRM) Grain 3.09 % 3.75 oz Hallertauer [2.30 %] (60 min) Hops 12.7 IBU 2.00 lb Candi Sugar, Clear (0.5 SRM) Sugar 6.04 % 2.00 oz Hallertauer [2.30 %] (15 min) Hops 3.4 IBU 0.80 oz Orange Peel, Bitter (Boil 15.0 min) Misc 0.48 tsp Grains of Paradise (GoP) (Boil 15.0 min) Misc 0.12 oz Corriander (crushed) (Boil 15.0 min) Misc 1 Pkgs French Saison (Wyeast Labs #3711) Yeast-Ale 1 Pkgs Belgian Saison (Wyeast Labs #3724) Yeast-Ale 6.00 lb Frozen Strawberry (secondary 21 days) (6.0 SRM) Adjunct 18.12 % 64 oz Apricot juice (3.0 SRM) Adjunct 1.51 %
Beer Profile
Est Original Gravity: 1.062 SG	Measured Original Gravity: 1.065 SG
Est Final Gravity: 1.012 SG	Measured Final Gravity: 1.003 SG
Estimated Alcohol by Vol: 6.58 %	Actual Alcohol by Vol: 8.10 %
Bitterness: 16.0 IBU	Calories: 285 cal/pint
Est Color: 7.1 SRM	Color: Color
Mash Profile
Mash Name: Single Infusion Mash, 1 Step, Light Body	Total Grain Weight: 25.11 lb
Sparge Water: 9.90 gal	Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F	TunTemperature: 72.0 F
Adjust Temp for Equipment: FALSE	Mash PH: 5.4 PH
Temperature Mash, 1 Step, Medium Body Step Time Name Description Step Temp 60 min Saccharification Add 31.39 qt of water at 160.4 F 150.0 F 10 min Mash Out Heat to 168.0 F over 10 min 168.0 F 30 min Fly Sparge Fly sparge with enough water to achieve pre-boil volume 168.0 F
Notes

5/13/2012: brew day

Substituted Hallertauer 60 minute addition for Tettananger
Used powdered coriander instead of crushed, and cut it from .29 oz additions to .12 oz.
Cut bitter orange peel from .96 oz to .80 oz.
Used 0.28 mm crush on grain mill. It seemed too fine. Next time ope in slightly.

Measured pre-boil gravity without sugar was 1.052. With sugar it would have been 1.057.
I forgot to add the candy sugar until the last 5 minutes of the boil.
Measured OG was 1.065.

6.5 G fermentor got the 3711 French Saison yeast cake from a previously brewed Sorachi Ace Saison.
6 G fermentor got a 1.5L starter of 3724 Belgian Saison, and was ramped from 73 to 90 degrees over 24 hours.
The Belgian Saison yeast took off vigorously within 12 hours, then subsided within 24 hours. 36 hours later, there was no visible sign of fermentation.
The French Saison yeast took off with a medium krausen (no blow off), and 36 hours later it was still chugging along.

05/26/2012 (13 days) - Pitched 32 oz apricot juice (bottle from local health food store) and 3 lbs defrosted frozen strawberries (Kirkland brand from Costco) into each fermentor. Strawberries were broken up with a potato masher.

06/03/2012 (21 days) - gravity readings:
French saison = 1.003; Belgian saison = 1.029
Will crash cool the French saison for 48 hours, then transfer to a keg. The Belgian saison was moved to ambient heat and will get pitched with the French saison yeast cake.

06/05/2012 (23 days) - Transferred French Saison version to keg and bottled about 3-4 750ml bottles. Transferred the Belgian saison version to secondary and added the washed French saison yeast.

06/17/2012 (35 days) - Belgian saison (pitched on French saison yeast cake) gravity reading 1.011. Bottled 3.17 gallons (12 liters) with 2.4 oz priming sugar, which should calculate out to 2.25 volumes of CO2, unless the Brett takes the FG below 1.011 (edit: it sure as hell did!)
(7) 750ml bottles were bottled with ECY05 (half of a container), and (9) 750ml bottles were bottled with washed cake of ECY20 (from a Sanctification clone). All bottles were bottle conditioned for several months before trying.

7/7/2013 - All of the bottles were super gushers from the beginning. It's actually amazing that they have not exploded. I made a rookie mistake of bottling too early when using Brett and bacteria. Both versions are tart and full of fruit, but there is way too much fruit floating around in the bottles, and due to the bottles being gushers, everything gets stirred up and quite cloudy.

Tasting notes and comments:

Many months have passed since I have had the non-wild versions of this beer, and proper tasting notes do not exist. From memory, I recall the fruit character being a bit overwhelming and gave the beer a sweet characteristic, despite the low 1.003 finishing gravity. Changes that I would make to the recipe would be to scale back the amount of fruit character and change the primary yeast to the now regularly available WY3724. I would reduce the strawberries by 1 lb (2.5 lbs/carboy) and substitute the apricot juice with 2 lbs/carboy of fresh apricots. A version with no fruit and pitching BKYeast C2 in primary alongside WY3724 would also be interesting.

The versions bottle conditioned with ECY05 and ECY20 are coming around nicely, with ECY05 having a slightly more funky character, while ECY20 is more sour.

To refresh my memory, I opened a bottle of the ECY20. Even after chilling in the freezer for 30 minutes, the bottle was a gusher, causing the yeast and fruit sediment at the bottom to mix into solution.

Appearance:
Cloudy reddish amber color with a huge, white, fizzy head that diminishes quickly, leaving behind a modest amount of lacing. The beer is hazy from the yeast and fruit particulates being stirred up by the gushing bottle.

Smell:
I would be hard-pressed to find a more prevalent and pleasant, fresh-picked strawberry aroma than what is wafting out of this glass. Mixed into the background of the dominant strawberry aroma are fresh picked wildflowers. If I didn't know that Brett was in this beer, I wouldn't have guessed it. Although, Brett's oxygen scavenging capabilities have kept this beer smelling as fresh as the day that I bottled it. Actually, even more fresh and perfumey, if that is possible.

Mouthfeel:
Spritzy, Champagne level carbonation bites at the tongue. There is just enough body to keep the beer from tasting thin on the palate.

Taste:
The fresh fruit is more muted in the flavor profile than it is in the aroma, but it is still there. There is just enough alcohol present to let you know this beer is not a 4-6% beer. The lactic acid is present enough to qualify this as a moderately sour beer. No acetic acid can be detected. A slight tannic bite on the finish that I can only associate with new oak, persists for several seconds.

Overall:
I'm quite impressed with how much fresh strawberry comes through on the nose; the smells coming out of the glass are beautiful and captivating (everyone that I have poured this for has made a big deal about the aroma). The slight booziness and tannic astringency on the finish could be done without, and the carbonation is way into the dangerous level for glass bottles.

0 IBU 100% Brettanomyces fermented IPA

A Crooked Stave WWBG clone recipe

There are few things I enjoy more as a brewer and beer enthusiast than (1) randomly discovering a new brewery that makes excellent beer, and (2) being introduced to a new beer style or process that works out magically. My introduction to Crooked Stave Artisan Beer Project gave me both.

I randomly stumbled across Crooked Stave while on vacation in Fort Collins in 2011, shortly after Chad Yakobson started gypsy brewing out of Funkwerks (another great brewery, if you don’t know about it). This was my first experience with 100% Brettanomyces fermented beers. The first two beers that I had from Crooked Stave were WWBR and Pure Guava Petite Sour. It was hard to believe – other than the fact that both were gushers - that they had gone from boil kettle to bottle in about 6 weeks time.

One of my favorite examples of this fast, 100% Brett fermented style is Wild Wild Brett Green (WWBG), a highly hopped, dank, tropical fruit bomb that when consumed fresh presents more like an IPA than anything else. I was intrigued and wanted to make something similar myself. Chad helped me design the recipe below. My recipe is almost entirely his recipe, except I substituted East Coast Yeast Brett blends for Chad’s proprietary Brett strains, and used Amarillo and Nelson hops instead of Galaxy due to the limited supply of Galaxy at that time.

 

WWBG (1.1) Amarillo

[Not so] American IPA

 

Type: All Grain	Date: 3/30/2012
Batch Size: 11.50 gal	Brewer: Luke
Boil Size: 14.73 gal	Asst Brewer: Eric
Boil Time: 90 min	Equipment: Blichmann 20 Gal brewing system
Taste Rating(out of 50): 30.0	Brewhouse Efficiency: 70.00
Ingredients
Amount Item Type % or IBU 23.18 lb Brewer's Malt, 2-Row, Premium (Great Western) (2.0 SRM) Grain 79.99 % 2.90 lb Munich Malt - 10L (10.0 SRM) Grain 10.01 % 1.45 lb Carapils (Briess) (1.5 SRM) Grain 5.00 % 1.45 lb White Wheat Malt (2.4 SRM) Grain 5.00 % 2.25 oz Amarillo Gold [10.30 %] (0 min) (Boil) Hops - 7.75 oz Amarillo Gold [10.30 %] (15 min) (Aroma Hop-Steep) Hops - 7.75 oz Amarillo Gold [10.30 %] (Dry Hop 14 days) Hops - 5.47 oz Amarillo Gold [10.30 %] (Dry Hop 7 days) Hops - 1.23 oz Nelson Sauvin [12.20 %] (Dry Hop 7 days) Hops - 1 Pkgs BRETT blend #1 (ECY) (East Coast Yeast #ECY04) Yeast-Ale   1 Pkgs BRETT blend #9 (ECY) (East Coast Yeast #ECY05) Yeast-Ale
Beer Profile
Est Original Gravity: 1.065 SG	Measured Original Gravity: 1.065 SG
Est Final Gravity: 1.017 SG	Measured Final Gravity: 1.010 SG
Estimated Alcohol by Vol: 6.18 %	Actual Alcohol by Vol: 7.18 %
Bitterness: 0.0 IBU	Calories: 290 cal/pint
Est Color: 5.7 SRM	Color: Color
Mash Profile
Mash Name: Single Infusion, Medium Body	Total Grain Weight: 28.98 lb
Sparge Water: 4.82 gal	Grain Temperature: 72.0 F
Sparge Temperature: 168.0 F	TunTemperature: 72.0 F
Adjust Temp for Equipment: FALSE	Mash PH: 5.4 PH
Single Infusion, Medium Body Step Time Name Description Step Temp 60 min Mash In Add 36.24 qt of water at 162.8 F 152.0 F 10 min Mash Out Add 20.29 qt of water at 203.1 F 168.0 F
Mash Notes: Simple single infusion mash with fly sparge.
Notes
3/30/2012: 0 minute hop addition was at flameout, Aroma steep addition was 15 minutes post flameout, and the hops soaked for 15 minutes before chilling to 67F. Pitched one carboy with ECY04, and one with ECY05 Batch size of 11.5 gal yielded closer to 10.5 gal (5.25 gal into each fermentor) due to the large hop loss. 04/10/12: 10 day gravity reading (with shitty, non-precise hydrometer): ECY04: 1.014 ECY05: 1.025 Transferred to kegs for secondary/dry-hopping. ECY04 dry hop: 35g Nelson Sauvin/60g Amarillo (waiting on ECY05 to come down in gravity before dry-hopping) 4/19/12: ECY04 removed dry hops and added 2nd dry hop (110g Amarillo). Put in keezer to dry hop at 39 degrees for 2-3 weeks. (check back on 5/3/12). ECY05 - Added 1st dry hops (95g Amarillo). Gravity was still high. Will give it through 4/29/12 before switching out hops. *Additional gravity readings were taken, but not recorded. I believe both versions eventually got down to about 1.007 before cold crashing. ECY05 was left to condition for an additional month before the 2nd dry hop addition was added.

Tasting Notes and Thoughts:

ECY04 - Aromas were mostly tropical (papaya with some pineapple) and citrus, with slight traditional Brett earthiness in the background. The mouth feel was medium with some dryness from the hop compounds. After a couple of weeks on draft, the flavors became integrated and more complex. The Brett gained more fruit ester complexity over time at the expense of the "fresh fruit" aroma.

ECY05 - This version went to my friend Mark's house, so I was less familiar with it and am reporting based on memory. I remember more (but light) barnyard notes, with slightly less tropical flavors - more in the direction one would expect from a beer fermented with Brettanomyces.

While I would not call either version an outright “clone” of WWBG, I would say that both were cut from the same cloth as the beer that inspired them. The propriety strains that Chad used in the Crooked Stave version were specifically chosen for their clean, low ester profile, and their fast attenuation. Galaxy hops also have a distinct aroma and flavor that is difficult to achieve with other hops.

Both of these test versions were good, but I preferred the ECO4 to the ECY05 for this style. It's cleaner and the Brett doesn't compete with the hops. This could have been due to the faster fermentation and quicker consumption of the ECY04, but I would say it’s primarily due to the characteristics that ECY05 produces (barnyard, horse blanket, etc.). Even in the original WWBG version brewed by Crooked Stave, I noticed a big change in the character from when I had it fresh to when I had it a couple of months later. The hops faded and complex Brett notes began to develop. Even so, the next time that I try something similar I will use a more fruit-forward Brett strain (e.g., Trois, BKY C2/C3).

What is coming in the near future…

I took a look into the Metabrewing crystal ball and saw several posts that will be coming in the near future.
Here are some of the upcoming posts…

Recipes:

• 100% Brett fermented 0 IBU IPA (you read that right, there are no typos)
• Berliner Weisse aged on Brett
• Saison inspired by Fantôme
• India Pale Saison

Experiments:

• The great Brettanomyces showdown - the same base wort 100% fermented on 9 different single brettanomyces strains…and then sampled (of course).
• Using extracted hop oil for flavor/aroma contribution

Equipment/Process:

• My semi-automated brewing setup
• Keg cleaning
• Brewing water

*If you feel the urge to be notified on these upcoming blog posts, you can subscribe via email, RSS/ATOM feed, or add me on Google+, Facebook or Twitter.

American Black Ale (Black IPA) Tasting Notes

Even though I can drink, and even enjoy, a well-made American Black Ale (Cascadian Dark Ale, Black IPA, etc.), it's a rare day that I order one given a number of options to choose from. I find myself picking a quaffable APA/IPA if I am in the mood for hops, or selecting a porter/stout if I'm craving a dark, malt-driven beer. Roasted malts and hop aroma/flavors can be made to work together, but the whole isn't necessarily better than the sum of its parts.

Here are tasting notes from my American Black Ale that had 17 oz of hops in the flameout and whirlpool, and another 14 oz of dry hops. The recipe was designed as a 12 gallon batch, but I only netted about 9 gallons of beer, thanks to those thirsty hops.

My goal was to make an American Black Ale that accentuated the hop characteristics and downplayed the dark malts as much as possible. For the recipe, read the original post. Here's how my version turned out:

Appearance

It pours from the tap with frothy, cappuccino-like head that fills half the glass and then persists for over 10 minutes, leaving behind sticky tan lacing and a thick ring of foam that persists until the glass is empty. The beer is deep brown to black. When held up to a light it remains opaque except for a reflection that makes its way through the bottom of the glass, highlighting the beer's clarity. I don't typically think of dark beers in terms of their haziness, but this beer has none.

Aroma

Even after 2-1/2 months in the keg, a big hop presence leads the way, first with pine and cedar, then followed quickly with orange rind, dank and catty notes. Getting past the hops, a hint of fruity dark chocolate is present, but I'm reaching for it. The color makes me look for aroma characteristics that correspond to a dark beer. No sign of roast or toast in the nose.

Taste

Bright citrus hops are the first thing coating the front and sides of the tongue, followed by a flavor that I can only describe as reminiscent of a dark chocolate bar infused with pieces of orange. There's a lingering bitterness (more than I care for).

Mouthfeel

Medium body and dry, with a slightly oily presence, which I'm assuming is from the massive amount of late addition hops in the recipe. The hops cling to the back of the tongue, leaving behind a lingering dry astringency that substantially adds to the perceived bitterness. 

Overall Impressions/Final Thoughts

For the style, I'm happy with how this beer turned out. There is more hop aroma wafting out of the glass than I have ever encountered in an American Black Ale. The Midnight Wheat has done its job in adding color while contributing little to no roasted malt flavor. It still provides some dark chocolate undertones, but they are more muted than the commercial examples of the style that I have tried.

If it is possible to go overboard with hops, this recipe is living proof of it. Changes I would consider for the next attempt would be to reduce the total volume of hops (0.75-1.0 oz/gal), raise the original gravity (1.077-1.085), or both. The malt balance is great, but the astringency on the finish contributed from polyphenols in the hops is a bit over-the-top for my taste for a beer of this gravity.

Recirculating Dry Hops: Extract More Aroma Oil in Less Time

When I think of a good “hoppy” beer, my mind conjures up interesting aroma and flavor profiles. Bitterness units barely factor in. A hop forward beer that has lost (or never really had) aroma becomes a boring and uninteresting beer.

What if you could get more aroma oil extracted from your dry hops with less time? Would you do it? That question almost sounds rhetorical.

Early last year I came across an Indie Hops blog post titled, “More Aroma Oil, Faster: The Dry Hopster’s Holy Grail.” With a title like that, I had to keep reading. The post cited a study by Peter Wolfe and Dr. Tom Shellhammer at the Oregon State University Department of Food Science which compared the aroma/flavor potential of two dry hopping materials (whole cone hops vs. pelletized hops) and the effectiveness of two methods for dry hopping (stirred vs. unstirred). All dry hopping took place at 23.2°C (73.76°F). Both sensory analysis (a tasting panel) and instrument analysis (measurements of compounds) were performed on samples taken at 0.5 hours, 2 hours, 4 hours, 6 hours, 24 hours, 4 days, 7 days, and 12 days of exposure to hops.

Peter Wolfe’s thesis, A Study of Factors Affecting the Extraction of Flavor When Dry Hopping Beer, is published on Oregon State University’s website. I read all 92 pages of it, which took me a while because I found myself searching Google every other page to research a new [to me] unfamiliar term.  There were several interesting findings in the study. Here are a few highlights:

• Pelletized hops resulted in faster extraction and more hop aromatic compounds compared to dry hopping with whole cone hops.
• Stirring hops resulted in higher overall aroma compound extraction and more intense aroma perception than unstirred hops.
• Stirred pellet hop aroma compounds were nearly fully extracted after 24 hours.

“Say what? 24 hours?!”  (That was my reaction, anyway.)

Aroma, Aroma, Aroma

As pervasive of a practice as dry hopping is in modern beer brewing, there is a lot of confusion as to what is exactly going on during the dry hopping process. This gives rise to all kinds of practices and procedures for how to achieve the best results. This post is not attempting to address every aspect of dry hopping (bitterness contribution, antimicrobial properties, etc.). For that, I would recommend reading Peter Wolfe’s thesis as well as the book, For the Love of Hops, by Stan Hieronymus.  This post is only addressing the primary goal of dry hopping: aroma.

By far, the greatest reason that dry hops are used today is to add hop aroma and flavor (a combination of aroma, taste and mouthfeel) to beer. While other hop components (alpha/beta acids, polyphenols, glycosides and bio-transformed hop compounds) affect the overall flavor experience (see section 1.3 of Wolfe’s Thesis), the primary components of hops that directly contribute to aroma while dry hopping are terpene oils and sulfur compounds. The goal when dry hopping is to extract those compounds out of the hops and into the beer.

Most homebrewers follow a similar procedure to one another when dry hopping: steep the hops in fermented beer. Regardless of whether whole cone or pelletized hops are used, if hops are placed in bags or allowed to free float, or if the dry hops are added to the primary, secondary or keg, the universal practice for dry hopping at the homebrewing level is to allow the hops to soak in beer post fermentation without any form of agitation.

On the other hand, the commercial breweries that are best known for aromatically hoppy beers all use some form of agitation or extraction beyond simply steeping the hops in the beer. Dogfish Head, Russian River Brewing and Firestone Walker use a “Hop Cannon,” Sierra Nevada uses a “Torpedo,” and New Belgium and Stone use “The Slurry Method” (chapter 8, For the Love of Hops). Commercial breweries have efficiency and time constraint requirements that homebrewers do not have, but as Peter Wolfe found in his study, a greater level of hop aroma compounds are extracted through agitation.

My dry hop agitation setup

After reading Peter Wolfe’s thesis, I was determined to come up with a way to agitate dry hops at the homebrewer level. The first idea was to build some sort of false bottom stir plate for my fermentation fridge, and then spin a large stirbar in a glass carboy to agitate the hops (I still like this idea). However, I recently obtained a stainless steel conical fermentor and wanted to move my fermentation of hoppy beers to the conical. What I came up with was the following setup, which as it turns out is almost exactly the same setup that was used for agitation in the study conducted by Peter Wolfe (I ran it by him).

Below is a diagram (and below that, a video) of how I do my dry hop agitation. The setup is slightly different than what is pictured below. I do not own a Blichmann brand conical, and I use the standard inline head rather than the center inlet head. I’m also sans a racking cane on the conical at the moment. I would highly recommend one is used with this setup. Without a racking cane, hop matter will come through the racking arm port. It will require a significant amount of dumps from the bottom to get all of the hops out. I waste a lot of beer dumping hops out of the bottom before I have clean enough beer to rack to a keg. A racking cane will allow the tube to point up and out of the hop slurry so that clean beer can be racked without having to dump any hops.

Here is a YouTube video of my setup in action:

Continuously recirculating dry hops in the fermentor

What you’ll need

Assuming you already own a conical fermentor, to pull this off you’re looking at purchasing the following:

• (1) March or Chugger Pump (I use one that I already had)
• 3-4 ft of 1/2” ID tubing (I use silicone, because I can boil it before use to sterilize it)
• 4 connectors for the inlet and outlet tubes. Everyone’s setup is different, so this will vary depending on your configuration. My conical uses 1.5” triclover fittings, and my pump is 1/2” NPT, so I purchased:
  (1) 1.5”x1/2” barb fitting and (1) 1.5”x1/2” barb with 90° bend (I like the 90° fitting more because it can get out of the way, so I’d go with 2 of those if I did it again).
  (2) Blichmann Stainless QuickConnector - 1/2in. 90° Elbow Barb. For whatever reason, the Blichmann elbow barbs barely have any barb at all on them. The Blichmann straight barb fittings are much more grippy and in line with what you would expect a barbed fitting to be like, so I would go with those next time.
• (4) hose/tubing clamps (large) for the fittings

Non-conical fermentor configurations:

I have not attempted this in any fermentor other than my conical. I would like to see how other brewers approach this situation with carboys and Sanke kegs. If you have recommendations to share in the comments, please do so.

Carboys:

In addition to the stirbar idea that I mentioned above, a carboy cap can be modified to accommodate two racking canes, like this. You can then follow a very similar process to what I did with my setup. You would want to ensure the hole was not cut too large, because oxygen making its way in will be counterproductive to the goal of making an aromatic hoppy beer. If you would rather use a stopper than a carboy cap, Morebeer sells a #6.5 stopper with 2-holes, but the 2nd hole is too small for a racking cane, which means that changes would be needed. A ball valve would need to be added to this configuration to be able to adjust the flow rate of the pump.

Sanke kegs:

Before I purchased my conical, I used the Sanke fermentor kit from BrewersHardware. As with the carboy cap above, the blowoff hole could be modified to accommodate a 2nd racking cane.

Results to come in a follow-up post. Stay tuned...