Thursday, June 21, 2012

Kentucky Bound

Beautiful Kentucky Lake
I'll be heading to the South Central United States later this week for an extended vacation on the shores of Kentucky Lake.  It's a beautiful place, wooded and green with inlets and waterways weaving in and out of two massive bodies of connected water.  It's become an (extended) family tradition to spend a week there with friends every other summer, leaning hard on the generosity of the Lewis family, who graciously invite us to stay there and enjoy their vacation home.  The trip is mostly about connecting with family and friends in a place devoid of airs and expectations.  We swim and boat on the lake, cook communal meals, relax in the cabin, watch the kids play, and generally just unwind.  This year there are five families going-seventeen people in all!  

As you might expect, we also drink some beer while there.  Traditionally, each person selects a brand of American Lager to drink.  This helps distinguish who beers belong to and facilitates consumption at "vacation levels."  In the past, I've always gone with Busch.  It is pretty tasteless and smooth, with a nice solid 4.7% ABV (higher than most others in the same category) and its irreverent slogan is somehow endearing ("Cold As A Mountain Stream, Smooth As Its Name").  This year I got curious about craft beer in Kentucky so I did a little research, figuring there might be a local brew I could pick up instead of mass-produced, soulless swill.  The results are a little discouraging.  The latest comparative statistics are from 2009 and list 6 total breweries in the entirety of the Bluegrass State; California boasted 238 in that same study.  Granted there have been some changes in the past few years with more breweries opening and even more planned.  The Brew Grass Trail website keeps an updated list of craft breweries in KY, but there's not much where we're going.  I guess I'll be sticking with Busch again this year.  We have an equation that we use to figure out how much beer to purchase en route to the lake house, as it is located in a dry county and you have to plan ahead:  

[d x b] x r  =  h


d = days in KY
b = number of beers you'd drink daily in ideal conditions
r = the responsibility factor (expressed as a decimal number less than 1 to indicate % fewer beers you would consume if you were supposed to be "responsible")
 = exponential value to be assessed in relation to r determined by the number of kids you have
h = beer number representing your happy place

I ended up with 84 beers.  It's going to be a good vacation...

Saturday, June 16, 2012

Lagerkeller Korrekt

Bière de Garde - Ambrée and Peacesteiner Bavarian Dunkel (L to R) in the kegerator, converted for lagering.

I brewed a Bavarian Dunkel and a Bière de Garde Ambrée  last week as part of my (semi-) annual summer foray into lagering beers.  Both beers were made over the course of a 9 hour brew day that included brewing both beers (with an extended boil for the Ambrée), the bottling of my Golden Raisin Dubbel, and some side-by-side tasting of Kate the Great clones with Lewy.  I've learned a lot about making lagers correctly from books (particularly John Palmer's How to Brew), various sources online, and interviews (and from screwing up previous batches) so I figured I'd share some of my thought processes as applied to these beers.  The whole point of lagering is to create a clean, (often) maltier, crisp, smooth finished product, devoid of diacetyl and other off-flavors, and lacking the fruitiness associated with ale fermentations.  All of this is achieved by way of strict temperature control.  Here are the points/processes I have found important:
  • A very large yeast starter ensures that primary fermentation begins properly.  I pitched roughly 1000ml of slurry into both the dunkel and the ambrée.  While making and building the starter, working at room temperature is acceptable, but prior to pitching the yeast, the starter should be at roughly the same temperature as the wort.  I cool my wort (after chilling with the counterflow chiller) down to the desired lager temperature in my converted kegerator, and place the yeast starter inside to ensure that they are the same temperature when pitching occurs.
  • Lager yeasts prefer a cooler and strain-specific temperature.  All yeast would happily ferment at warmer than normal brewing temperatures.  We control temperatures to coax the flavors we desire from the yeast.  It's important to stay within the range of primary fermentation temperatures for the specific strain that you choose to work with.  If you allow the temperature to rise too high, then you may be dealing with off-flavors in the final product.  If you drop the temperature too low, then you may have a sluggish or even stuck primary fermentation due to premature flocculation/settling.  WLP830 - German Lager ferments best at temperatures between 50-55°F.  I read temperature using a vial that has wort in it left over from hydrometer testing.  I keep a thermometer in the vial and adjust temperature accordingly with a digital controller.  My beers are fermenting at 52°F.  
  • A diacetyl rest is important.  It's easy to do, too.  Diacetyl is that butterscotch flavor/aroma that is only vaguely acceptable in a very few styles of beer (English Barleywine, Oud Bruin, English IPA, some Stouts come to mind) at very low levels, and is pretty much universally considered a flaw in lagers.  I know that different yeast strains are more likely to produce diacetyl, and that some may not warrant a diacetyl rest, but I figure it to be a simple safeguard.  All you have to do is raise the temperature to between 55-60° F for 48 hours at the end of primary fermentation.  This allows the yeast to become increasingly active and clean up any diacetyl that might be present prior to cold conditioning.
  • Minimize the impact of autolysis by transferring after the diacetyl rest.  Dead, ruptured yeast cells release undesirable off-flavors into beer.  With a large lager pitch you have a yeast mass that has the potential to impart a significant number of those off-flavors into your precious beer.  Transferring the beer off the yeast cake prior to cold-conditioning helps to prevent this from happening.  Pitching healthy viable yeast helps to minimize autolysis, too.
  • Cold condition your beer at 10°F less than primary fermentation.  If you go too much lower then you risk shocking the yeast, which have become accustomed to working in a specific temperature range.  It's also a good idea to drop the temperature gradually (i.e. a degree or two per day).  Doing so prevents the yeast from dropping to the bottom and going dormant.  You want the yeast to continue to clean up your beer (albeit more slowly) during the lager phase.  Depending on your lagering temperature, the conditioning phase could take between 4 and 8 weeks.  Colder conditioning temperatures require more time to finish.
I plan to condition these beers for about 6 weeks at around 42°F.  I'll be watching fermentation carefully to make sure that I complete the diacetyl rest/transfer right near the end of primary fermentation.  I'll be kegging these beers.  They'll be on tap when my kegerator comes back online.


The kräusen forming as each of the beers ferments is some of the most unique and beautiful I've seen in a while.  I don't know whether that's attributable to the lager yeast or not.  Regardless, it's interesting to look at.
Peacesteiner Bavarian Dunkel
Ambrée Bière de Garde

Friday, June 8, 2012

Melanoidins and Lagering

For most of the past few summers, I've taken some time off from drinking, tapped out the kegs on draft, dropped my kegerator temperature, and lagered two beers for roughly two months with varying degrees of success.  In 2008 I made my first lagers, a Bohemian Pilsner and a Vienna Lager that left plenty to be desired.  In 2010, I brewed a very nice Schwarzbier and a decent Marzen.  Last summer, I made a Baltic Porter that I was really proud of and a California Common that was a favorite among friends.  This year, I want to continue to do something different, trying styles and techniques that are unfamiliar and exciting.

The Maillard reaction works the same way - producing melanoidins - when applied to grain.

Yesterday I bought ingredients for this summer's lagers with a nod to the crusty, bready flavors that you get when using significant Munich malts.  I hope to make a bavarian dunkel that harnesses those melanoidins (created via the Maillard reaction) and brings them to the forefront with a clean, attenuative lager yeast, much in the same vein as Warsteiner.  With similar intention, I hope to make a biére de garde ambrée that has qualities inherent in some of the better commercial examples I've been able to find (especially St. Amand's French Country Ale-though it is a brown version of the style).  Both beers will be using WLP830 German Lager Yeast, a popular strain cultured from Weihenstephan Abbey, the world's oldest continuously operating brewery.

I have a massive starter that began as two vials of WLP830 mixing away happily on my stir plate, and plan to brew both beers early next week.

Tuesday, June 5, 2012

Bottling Beer With a High Final Gravity

My clone of Portsmouth Brewing's Kate the Great Russian Imperial Stout was brewed in early February, and got off to a rapid start.  I used a roughly 1000ml starter of WLP060 - American Ale Yeast Blend to contribute some lager-like flavors to the finished beer, and I watched the gravity drop significantly in the first few weeks of fermentation.  After thirty days I transferred to secondary and added two ounces of medium toast American oak cubes that had been soaking in bourbon.  At that point, the gravity had gone from 1.120 (28.01°P) to 1.030 (7.56°P) and airlock action had stopped.  Since then, I've consistently checked the gravity every few weeks and there's been no change.

I've never bottled a beer with such a high finishing gravity before.  The threat of over carbonating and creating bottle bombs has been pounded into my psyche by my homebrewing forebears since I started firing up a kettle almost a decade ago. Besides simply tasting the flavor profile, there are a few factors to consider when deciding whether or not to bottle a beer with a high FG and they basically fall into two categories:

1) the diligent application of environmental controls (pitch amount, temperature, ph, nutrient availability, aeration, etc.) and

2) yeast selection and the associated characteristics (below) that accompany that choice:
  • ALE vs. LAGER:  This simple stylistic choice is pretty important for determining when a fermentation is finished, as lager yeast strains ferment a larger variety of sugars (specifically the trisaccharide raffinose composed of frustose, galactose and sucrose) which leads to greater attenuation.   
  • ATTENUATION:  This refers to the amount of sugars that your yeast is able to convert during fermentation.  Yeast have the potential to consume all available sugars and attenuate completely, but rarely do.  Homebrewers are interested in desirable flavors and therefore commonly ferment at a lower than optimal temperature for ideal attenuation.  Likewise, flocculation (basically clumping together and sinking) of yeast is a desirable characteristic, contributing significantly to a beer's clarity.  If attenuation was the sole concern, then yeast rousing could force the yeast to stay active.  This also plays a role in determining whether to add fresh yeast for bottling.
  • ALCOHOL TOLERANCE:  At some point the yeast produces enough ethanol that the environment becomes toxic and it begins to die.  Alcohol tolerance is a consideration when deciding whether to bottle with significant gravity remaining because it reveals how high alcohol can limit extended viability.
  • STYLE:  If you begin with a very high gravity, you should expect to treat the yeast and fermentation a little differently.  Likewise,  with the above considerations in mind some beers are meant to finish higher.  Russian Imperial Stouts can acceptably finish between 1.018 and 1.030 according to the BJCP.
It seems that having stable final gravity within the acceptable range is most important.  Since my KTG clone had maintained a stable gravity during the entirety of secondary fermentation/oaking, I felt relatively confident that the yeast was done.  The stats associated with WLP060 - American Ale Yeast Blend seemed to agree.  WLP060 attenuates to between 72-80%, with medium-high alcohol tolerance.  My KTG clone finished at 73% attenuation and 12% alcohol.  With the FG being at the very top of the style range, I decided to go ahead and bottle.

I added a package of Safale US-05, providing fresh yeast to do the work of carbonation, and 5/8 of a cup table sugar dissolved into a simple syrup.  I want lower than normal carbonation in this beer as too much masks some of the deeper flavors.  I plan to age it for an extended period of time, drinking one now and then to taste how it changes.
As an aside, I saved the oak cubes that I used in KTG and added them to Crumple Car Flanders Red.  Since this is their second application they should provide some moderate complexity prior to blending.  
Oak cubes retained from KTG.