Showing posts with label Hops. Show all posts
Showing posts with label Hops. Show all posts

Friday, November 14, 2014

Ceratogaulus Rye Ale

Ceratogaulus the prehistoric rodent is a fascinating little creature, with a deceptively obvious identifying feature: Two large horns protruding from its nose! Indeed, it is the only known rodent to have ever had horns, and one of only two fossorial (digging) mammals known to have had horns at all. Naturally, one may ask the question "Why did this particular rodent evolve horns??" Why, indeed! The most supported answer uses a combination of evidence from fossil bones and modern animals to address this very question.
This is a skull of Peltephilus, a fossorial xenarthran belonging to
the family Dasypodidae, which includes modern armadillos.
Peltephilus and Ceratogaulas are the only known fossorial
mammals with horns! Sadly, no horned fossorial mammals are
known to exist today. *Sad trombone*
Ceratagaulus: The only known rodent to have horns!
Here you can see the two horns projecting out of the skull.


The first piece of evidence comes from the now extinct family of rodents called the Mylagaulidae. Most known mylagaulids had skeletal adaptations for digging through soil, including broad, shovel-like hands with claws to match, and robust limb bones. Great for moving lots of dirt! In addition, mylagaulids also had adaptations for what is called head-lift digging, a method of burrowing that involves pressing the top of the head forward and up, compacting the soil. This requires some very strong neck muscles! Now, before you jump up and yell "Aha! Those horns were for digging!", let's dig a little deeper. With our heads.

This is the skeleton of a modern mole, which is not a
mylogaulid, or even a rodent. It is however a
fossorial mammal, with arms and hands
exceptionally well adapted for digging!









Research by Dr. Samantha Hopkins (2005) provides evidence against Ceratogaulus being able to angle those horns properly to dig with! They just couldn't tilt their noses down far enough to really push those horns into the soil in front of them. What's more, through the evolutionary history of the genus Ceratogaulus, those horns moved back on the skull, away from the tip of the nose where they would be of better use for digging. So, the horns-as-digging-tools idea is out. What about sexually dimorphic features, like the horns that rams use to fight for mates? In those cases, we would expect to see a difference in horn size - or presence - between male and female individuals. This sex-based difference is not found in Ceratogaulus. So, that hypothesis is probably out also. But the horns are clearly providing Ceratogaulus with an evolutionary advantage, otherwise they would not be present.

Defending oneself from predators is also a good reason to have some pointy objects sticking out of your head. No one likes to get stuck with pointy objects, especially when those pointy objects are being powered by some really strong muscles... Such as those powerful head-lift-digging mylagulid neck muscles mentioned earlier. Turns out those muscles can be used for other things too, like driving a pair of nose-spikes into an attacker! The flexing of those powerful neck muscles would snap the head dorsally, the same way your neck muscles contract to let you look straight up while standing. Lots of predators like to attack small rodents. They are very snackable, and once you get a hold of one, they rarely put up much of a fight. Those same predators commonly go for the vital head and neck regions to make a killing strike. The anatomy of Ceratogaulus - including the horns and attachments for the neck muscles - would have allowed it to protect itself from attacks to the head and dorsum of the neck by thrusting those two horns at any attackers! *JAB JAB!*


Dr. Hopkins has been kind enough to answer a few questions about her work on Ceratogaulus, including what kind of science still needs to be done to understand its biology. 


How did you first become aware of the two-horned wonder that is Ceratogaulus?

I first discovered Ceratogaulus in my first year of graduate school, when I was working on the description of a new species of aplodontid rodent. I was trying to find papers on all its relatives, and I came across mylagaulids, including Matthew's original paper describing the skeleton of Ceratogaulus hatcheri from Kansas. The figure at the end of the complete skeleton just totally blew my mind. Horns? What????

What made you decide to tackle the question of what the horns were for?

The horns question was an obvious one. There's no living analog, so it's one of those questions in paleo that requires really clever experimental design. Another project I was working on had just fallen through, and I managed to sell my advisor on the idea that figuring out what the horns did would be a really interesting sidelight in a project about lineage decline in the Aplodontidae, which were quite diverse in the Early to Middle Miocene.

What was the most challenging part of figuring out what Ceratogaulus horns were used for?

The challenging part of this problem is that, given that they're a fossil organism, you're forced to work with multiple hypotheses all at the same time. The only way to come up with an answer is to eliminate them one by one until there's nothing else left. Coming up with the evidence to eliminate some of the possibilities was tough, because some of them don't make a lot of predictions for what you should observe in the fossil record. Fortunately, Ceratogaulus left us a really good skeletal record.

Is there a particular Ceratogaulus specimen that is your favorite?

I don't have a favorite. I love all the children equally. In all seriousness, the thing I find really appealing about them is the sheer diversity. There are a lot of skulls, and the horns come in many different shapes. And that leads into....

Are there any lingering questions you have about Ceratogaulus that you would like to work on in the future?

Why are the horns so variable? What does the variation in horn shape mean? We're still working on this one, and it may turn out that some aspects of the answer weren't as simple as I initially thought. We still need more specimens, and more study of the specimens we have. It's a really interesting animal, and there's a lot left to know.



Cheers, you adorable little conundrum, you!


Art by Ursulav (ursulav.deviantart.com; redwombatstudio.com)

Rye has been a brewing grain of interest to me since I first tried Hoss from Great Divide Brewery. I'm not really a lager beer drinker. Not enough flavor, usually. The part about Hoss that got me interested was the rye. I was still pretty new to the craft beer scene at that time, and the idea of a beer made with rye seemed fascinating as well as odd. Isn't rye the grain used to make that dark colored bread that only seems to exist in upscale delis? Hmm....

The Hoss was pretty good. Not great enough to make me a lager convert, but a solid, interesting beer. The flavor complexity that the rye provided really held my attention. I've had a few rye beers since, most of them being pale ales or IPAs; I have a ryewine in my fridge waiting for a special occasion also. It's neat grain, and adds some interesting flavor to a beer that I wanted to make use of when I started homebrewing.

I knew when I started putting this recipe together that I wanted the beer to be malt-driven but not sweet, with a fairly light body. The rye was going to be the star of the show, but it didn't need to be an extravaganza. Subtle and complex was to be the name of the game. In pursuit of this goal, I decided to use both regular malted rye and caramel rye in the recipe, along with a low dose of intermediate strength hops. I also used a straightforward American ale yeast helped ensure a minimal yeast-based flavor contribution. Thus was born Ceratogaulus Rye Ale. A small (low alcohol) beer with some interesting complexity, and spicy malt kick!
Type: All Grain
Batch Size: 1.0 gal
Fermentation: Ale, Two Stage
Date: 31 Jul 2014
Brewer: David Levering

Ingredients
Amt Name Type # %/IBU
2 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 1 57.1 %
1 lbs Rye Malt (4.7 SRM) Grain 2 28.6 %
4.8 oz Crystal Rye (75.0 SRM) Grain 3 8.6 %
3.2 oz Caramel/Crystal Malt - 10L (10.0 SRM) Grain 4 5.7 %
0.10 oz Cascade [5.50 %] - Boil 30.0 min Hop 5 7.7 IBUs
0.10 oz Willamette [5.50 %] - Boil 30.0 min Hop 6 7.7 IBUs
0.10 oz Cascade [5.50 %] - Boil 10.0 min Hop 7 3.6 IBUs
0.10 oz Willamette [5.50 %] - Boil 10.0 min Hop 8 3.6 IBUs
0.10 oz Cascade [5.50 %] - Boil 5.0 min Hop 9 2.0 IBUs
0.10 oz Willamette [5.50 %] - Boil 5.0 min Hop 10 2.0 IBUs
1.0 pkg American Ale (Wyeast Labs #1056) [124.21 ml] Yeast 11 -
0.10 oz Cascade [5.50 %] - Dry Hop 3.0 Days Hop 12 0.0 IBUs
0.10 oz Willamette [5.50 %] - Dry Hop 3.0 Days Hop 13 0.0 IBUs

 

 Gravity, Alcohol Content and Color

Est Original Gravity: 1.065 SG
Est Final Gravity: 1.012 SG
Estimated Alcohol by Vol: 7.0 %
Bitterness: 26.7 IBUs
Est Color: 15.4 SRM
Measured Original Gravity: 1.046 SG
Measured Final Gravity: 1.010 SG
Actual Alcohol by Vol: 4.7 %
Calories: 151.6 kcal/12oz

Mash Profile

Mash Name: Single Infusion, Light Body, Batch Sparge
Sparge Water: 0.97 gal
Sparge Temperature: 168.0 F
Adjust Temp for Equipment: FALSE
Total Grain Weight: 3 lbs 8.0 oz
Grain Temperature: 72.0 F
Tun Temperature: 72.0 F
Mash PH: 5.20
Mash Steps
Name Description Step Temperature Step Time
Mash In Add 4.38 qt of water at 159.1 F 148.0 F 75 min

Sparge: Batch sparge with 2 steps (0.15gal, 0.82gal) of 168.0 F water
Mash Notes: Simple single infusion mash for use with most modern well modified grains (about 95% of the time).

Carbonation and Storage

Carbonation Type: Bottle
Pressure/Weight: 0.86 oz
Keg/Bottling Temperature: 70.0 F
Fermentation: Ale, Two Stage
Volumes of CO2: 2.3
Carbonation Used: Bottle with 0.86 oz Corn Sugar
Age for: 40.00 days
Storage Temperature: 65.0 F 
Tasting notes:

From Medhavi Ambardar:
"Don't change this recipe. It's great just the way it is."

From Win McLaughlin:
" (I'm) having a hard time coming up with much to critique on your beer David. It's excellent. I like the sweet notes with a bit of hop (but not so much as to be bitter). I think I could use a touch more malt to make the initial taste a bit more full bodied and continue to balance out the sweet flavors. Dylan (my male creature) is trying it too. he says it's 'very flavorful, not much hops, not bitter, slightly fruity'."


Sources cited

Hopkins, S.S.B. 2005. The evolution of fossoriality and the adaptive role of horns in the Mylagaulidae (Mammalia: Rodentia). Proceedings of the Royoal Society B, 272: 1705-1713. 

Thursday, July 31, 2014

Haast's Eagle Imperial IPA


Artist's rendition of a Haast's Eagle,
about to mess up some Moa in
prehistoric New Zealand. Art by John Megahan.




Imperial IPAs are, really, what took me from occasional beer enjoyer to beer fanatic and homebrewer. I think I can even single out the Great Divide Hercules Imperial IPA as the culprit. It's huge, punchy, and holy hops is that flavor strong! Citrus! Pine! Could it strip paint? Probably, and I wouldn't have it any other way! I think it's fitting then that the first recipe I made on my own and brewed successfully is an imperial IPA.
Those yellow clusters are called lupulin glands. That's
where all the resins and oils that give hops their
bittering and flavor/aromatic properties reside.
The inspiration for this IPA in particular came from perusing hops on the Northern Brewer site. At the time I had just started really reading about brewing beer, and knew what alpha acid is, and I had some idea about the other oils in hops that lend flavors to beer. I was looking through all these different hop varieties for a change of pace. I've had plenty of piney, citrusy IPAs, and I love them, but I wanted something a little different*. 

Turns out New Zealand is quite well known for its hop-growing climate, and has some really cool varieties that have been propagated there! Since I knew I wanted to make an imperial IPA, I focused on the high alpha acid hop varieties of New Zealand provenance. I settled on Pacific Gem and Nelson Sauvin. Both of these hops have really good bittering capability. Pacific Gem is the bittering workhorse of this beer, while Nelson Sauvin comes in later to provide bitterness and hop flavor+aroma. These high alpha acid hops are brought together for a beer that punches in at just over 90 IBUs (international bittering units). For those who are wondering what that number means exactly, Bud Light weighs in at 6.4 IBUs. The higher the IBUs, the more bitter the beer will be.  
This is a Harpy eagle, crouching and being gigantic on this guy's arm.
The Haast's eagle was about 1/3 larger! Also, check out the talons!

This brings me to the namesake of the beer. Originally I was going to call this one "Moa", but it turns
Pretty impressive, considering just how
huge Harpy eagles are.
out there is a brewery in New Zealand called Moa. So in the interest of not ruffling anyone's copyright feathers, I went for the lesser known but definitely more badass Haast's eagle (Harpagornis moorei). An eagle of nearly Tolkein-esque proportions, the now extinct Haast's eagle is believed to be the heaviest member of the Accipitridae, the family which includes eagles, hawks, Old World vultures, and kites.  Female Haast's eagles were larger and heavier than the males, weighing an estimated 31 pounds, with an 8.5 foot wingspan; estimates for male Haast's Eagles place them at 25 pounds, with a presumably smaller wingspan (Braithwaite 1992; Worth and Holdaway 2003). 



On the left is a Haast's eagle talon, compared to a Little eagle
talon on the right. Little eagles are a member of the genus
Hieraaetus, which was found to contain the closest
living relatives to the Haast's eagle by Brunce et al. 2005. 
Using recovered mitochodrial DNA from Haast's Eagle remains, Dr. Michael Brunce and his colleagues created a maximum likelihood phylogenetic tree to determine a possible ancestral origin for the massive bird of prey (Brunce et al. 2005). In an interesting twist, the Haast's Eagle is most closely related to the diminutive eagle genus Hieraaetus (Brunce et al, 2005). This implies a remarkable increase in size from the hypothesized ancestors of the Haast's Eagle, and provides an excellent example of island gigantism! Also of note is that the Haast's Eagle becomes giant while retaining the ability to fly. Most birds, such as the moa, elephant bird, and the dodo, all become secondarily flightless when they increase drastically in size, owed to a lack of terrestrial predators on their home islands as they were evolving (Brunce et al, 2005). Without any large mammalian carnivores around, Haast's eagles were almost certainly the dominant predator of the South Island of New Zealand, terrorizing the moa birds native to the island until the arrival of humans in approximately 1280 AD. Haast's eagles are believed to have gone extinct around the year 1400 AD, following the devastation of its food sources and broader ecosystem by humans (Allentoft et al. 2014). 

The red text shows the position of the Haast's eagle (Harpagornis moorei) among other birds of prey, including the Little eagle. Image from Bunce et al. 2005.


 



*Not to say I didn't order some punchy pine and citrus flavored/aroma hops for other beers I am working on...




Haast's Eagle Imperial IPA

Type: All Grain


Batch Size: 
1.10 gal


Boil Size: 
1.64 gal



Boil Time: 
60 min
End of Boil Vol: 1.14 gal

Final Bottling Vol: 1.10 gal

Fermentation: Ale, Two Stage

Brewer: David Levering

Asst Brewer: Medhavi Ambardar

Equipment: David's Brewing Equipment

Efficiency: 60.00 %


Est Mash Efficiency: 60.00 %





Prepare for Brewing

Clean and Prepare Brewing Equipment





Total Water Needed: 2.13 gal

Water Prep


Amt  Name  Type  %/IBU
2.13 gal  Distilled Water  Water  -
0.63 tsp  Gypsum (Calcium Sulfate) (Mash 60.0 mins)  Water Agent  -
0.30 tsp  Calcium Chloride (Mash 60.0 mins)  Water Agent  -
0.22 g  Epsom Salt (MgSO4) (Mash 60.0 mins)  Water Agent  -




Mash or Steep Grains

Mash Ingredients


Amt  Name  Type  %/IBU
3 lbs 1.3 oz  Pale Malt (2 Row) US (2.0 SRM)  Grain 72.00%
9.6 oz  Pale Malt, Maris Otter (3.0 SRM)  Grain 14.00%
4.8 oz  Caramel/Crystal Malt - 20L (20.0 SRM)  Grain 7.00%
1.6 oz  Caramel/Crystal Malt - 80L (80.0 SRM)  Grain 2.30%




Mash Steps


Name  Description  Step Temperature  Step Time
Mash In Add 5.10 qt of water at 159.1 F  148.0 F  75 min

Batch sparge with 2 steps (0.04gal, 0.82gal) of 168.0 F water






Add water to achieve boil volume of 1.64 gal

Estimated pre-boil gravity is 1.059 SG





Boil Ingredients


Amt  Name  Type  %/IBU
3.2 oz  Candi Sugar, Clear (0.5 SRM)  Sugar 4.70%
0.10 oz  Pacific Gem [15.00 %] - Boil 50.0 min  Hop  22.7 IBUs
0.10 oz  Pacific Gem [15.00 %] - Boil 30.0 min  Hop  18.4 IBUs
0.10 oz  Nelson Sauvin [12.00 %] - Boil 20.0 min  Hop  11.6 IBUs
0.20 oz  Nelson Sauvin [12.00 %] - Boil 10.0 min  Hop  13.9 IBUs
0.20 oz  Pacific Gem [15.00 %] - Boil 10.0 min  Hop  17.3 IBUs
0.10 oz Irish Moss - Boil 15.0 min Clarifier
Steeped Hops


Amt  Name  Type  %/IBU
0.10 oz  Nelson Sauvin [12.00 %] - Steep/Whirlpool 10.0 min  Hop  3.5 IBUs
0.10 oz  Pacific Gem [15.00 %] - Steep/Whirlpool 10.0 min  Hop  4.3 IBUs




Estimated Post Boil Vol: 1.14 gal and Est Post Boil Gravity: 1.088 SG




Cool and Transfer Wort

Cool wort to fermentation temperature of 70 F. 

Transfer wort to fermenter

Add water if needed to achieve final volume of 1.10 gal

Pitch Yeast and Measure Gravity and Volume





Fermentation Ingredients

Amt  Name  Type  %/IBU
0.2 pkg  London Ale Yeast (Wyeast Labs #1028) [124.21 ml]  Yeast  -
Starting Gravity Target: 1.088

Add water if needed to achieve final volume of 1.10 gal





Fermentation


Primary Fermentation (4.00 days at 67.0 F ending at 67.0 F)

Secondary Fermentation (17.00 days at 67.0 F ending at 67.0 F)





Dry Hop and Bottle/Keg

Dry Hop/Bottling Ingredients

Amt  Name  Type  %/IBU
0.20 oz  Nelson Sauvin [12.00 %] - Dry Hop 7.0 Days  Hop  0.0 IBUs




Final Gravity Estimate: 1.013

Date Bottled/Kegged: Carbonation: Bottle with 0.86 oz Corn Sugar
Age beer for 14.00 days at 65.0 F

Age beer another 14 -21 days at 45-50 F. 





Notes


Additions to be made to the heated water before it is mixed with the malted grains:
Gypsum: 0.63tsp


CaCl2: 0.2tsp


Epsom Salt: 0.22tsp

Phosphoric acid addition: 2tbs















Dry hops should be added using a muselin bag to prevent them from creating a mess inside the fermenter. This is especially true if using pellet hops. Make sure the fermenter is well sealed during the dry hopping phase to prevent volatile aromatics from escaping the beer. The first 4 days of the dry hopping should happen at around 65 degrees F. For the final 3 days, cold crash the fermentor to 40-50 degrees F. Before bottling, remove the muselin bag full of hops from the fermenter.

 

References
Brathwaite, D. H. 1992. Notes on the weight, flying ability, habitat, and prey of Haast's Eagle (Harpagornis moorei). Notornis (Ornithological Society of New Zealand), 39: 239–247.

Bunce, M., Szulkin, M., Lerner, HRL., Barnes, I., Shapiro, B., Cooper, A., Holdaway, R.N. (2005) Ancient DNA Provides New Insights into the Evolutionary History of New Zealand's Extinct Giant Eagle. PLoS Biol, 3: e9.


Worthy, T. & Holdaway, R., The Lost World of the Moa: Prehistoric Life of New Zealand. Indiana University Press (2003).

Allentoft, M.E., Heller, R., Oskam, C.L., Lorenzen, E.D., Hale, M.L., Gilbert, M.T.P., Jacomb, C., Holdaway, R.N., Bunce, M. 2014. Extinct New Zealand megafauna were not in decline before human colonization. PNAS, 111: 4922-4927