Azacca Session IPA

A few weeks back, I attended the National Homebrewers Conference in San Diego. One of the highlights (among many) was a lecture on "Brewing Session Beer" by New Belgium Brewing's Andy Mitchell, focused on brewing low-alcohol but high-flavor beers. My overall tastes (particularly for stuff I am going to put on tap in 5 gallon quantities) tend towards beers in this domain. I like to be able to enjoy a beer or two without ending up completely buzzed (and I want my liver to hold up for a few more decades of enjoying homebrew). One of the really interesting parts of Mitchell's lecture focused on brewing session IPA's, with a particular eye towards getting a beer with some nice body and flavor while avoiding watery mouthfeel.

Tips for brewing a session IPA (taken from my notes) included:

• Malt
• Less malt means less flavor! Instead of reducing the amounts of all malts in the beer (relative to a higher gravity grain bill), just scale back the base malt and leave the specialty malt as usual. If you scale back everything, it may result in a watery beer. 
• As another alternative, use a more flavorful base malt, with as Vienna or Maris Otter.
• Use a higher temperature mash rest, up to 158°. This will result in a greater proportion of unfermentable sugars, which will result in a bigger body for the finished beer.
• Consider a shorter mash time. [my question is if the mash is cut too short, is there a risk of an over-starchy beer?]
• Hops
• Balance is key; due to the lower starting gravity of session beers, you don't want to overhop. A smaller addition of hops in a session IPA can result in perceived bitterness equivalent to that of a higher gravity IPA with more hops.
• The bitterness ratio (IBU/SG) can be a useful tool to guide you. For an IPA, you might want to aim for a ratio of around 0.8 (e.g., 35 IBUs / 1.044 s.g.).
• Use a "hop burst" technique instead of a bittering addition. This gives increased aroma and avoids over-bittering the beer. In practice, this means adding hops only for the last 10 to 15 minutes of the boil.
• Water
• Avoid adding sulfate to the water; adding chloride can be OK. (oops, I forgot to follow this guideline in my recipe)
• Yeast
• A strain with relatively low attenuation is worth using. For this, consider stepping outside the box of what you normally brew. For instance, if you normally are aiming for American yeasts, look into the British yeast toolbox, because many of these finish less dry.
• Thames Valley strains are good for fermenting at lower temperatures with good character and relatively low attenuation.

Using these guidelines, I set out to design my own session IPA. Thanks to the AHA and BSG Craftbrewing, I had recently acquired 5 oz. of (free!) Azacca hops. It is a very North American strain, with lots of tropical and citrus (according the descriptions I've read). Additionally, the American Dwarf Hop Association suggests that it fares well in a single-hop beer. That's all the excuse I need to center my beer around this variety!

While designing this recipe, I used a few basic principles: 1) a simple malt bill utilizing a strong supplement to my usual 2-row base malt; 2) a high temperature mash to maintain a robust body for the beer; 3) hop bursting to maximize aroma and achieve a balanced bitterness; and 4) a British ale strain selected for comparatively low attenuation. In short, maximum body with balanced hoppiness. Thanks in part to all of the free hops, this batch was also pretty inexpensive: only $15 in raw materials. I'll find out how successful I was in a few weeks!

Azacca Session IPA

• 6.5 lbs. 2-row malt (Great Western Malting Co.)
• 3 lbs. 10° Munich malt 
• 1 oz. Azacca hops pellets (10.3% alpha), 15 minute boil
• 1 oz. Azacca hops pellets (10.3% alpha), 10 minute boil
• 1 oz. Azacca hops pellets (10.3% alpha), added at flame-out, steep for 5 minutes before cooling
• 2 oz. Azacca hops pellets (10.3% alpha), 2 week dry-hopping
• British Ale yeast (White Labs, WLP005), prepared in 0.75 L starter
• 1 tbs. 5.2 pH stabilizer (added to mash)
• 1 tbs. gypsum (added at first hops addition)
• 1 Whirlfloc tablet (10 minute boil)

Procedure

• I mashed in with 15 quarts of water at 169.8° and stirred for two minutes. The mash stabilized at 159°. After 50 minutes, the mash temperature was down to 157°.
• I added 1.1 gallons of water at 180°, to bring the mash temperature up to 160°. I let it sit for 10 minutes, vorlaufed, and collected 3.25 gallons of wort.
• Then, I added 3.75 gallons of water at 180°, to bring the mash up to 165°. I let it sit for 10 minutes, vorlaufed, and collected the remainder of the wort.
• All told, I collected 7 gallons of wort with a gravity of 1.038. This works out to 77% efficiency.
• I brought the mixture to a boil, adding the hops per the hopping schedule in the recipe (at 45 minutes, 50 minutes, and flame-out). This is essentially the "hop-burst" method, to gain all of the bittering units (with extra aroma) at the end of the boil.
• At flame-out, I let the beer sit for 5 minutes before starting cooling. This was with the intent of maximizing the hops aroma from the final addition.
• I cooled the wort and transferred it into the fermenter, aerating per usual with the Venturi pump. I pitched the yeast, sealed up the fermenter, and placed it in my fermentation chamber. The initial setting was for 68°. I had visible fermentation when I checked it seven hours later, and vigorous fermentation within 12 hours. At this point, I dropped the fermentation temperature to 66°.
• I brewed this beer on July 3, 2015. Starting gravity was 1.045, with an estimated 6 gallons of wort into the fermenter.

Azacca IPA reaching high krausen