Brew Notes: Beer Is A Vegetable (Cream Ale)

The concept for this beer started off with drunken ramblings with some great colleagues and friends - “Beer is made from hops. Hops is a flower. Therefore, Beer is a Vegetable”. Classic!

With this in mind we attempted a brew using reasonable types of “vegetables”. Stuff like celery and broccoli would probably contribute nasty off flavours, so we settled on time-tested brewing adjuncts such as sweet potato, corn and rice instead. These starch-based adjuncts are useful in a cream ale, as they ferment out almost completely to thin out the body and create a lighter mouthfeel. Carrots were meant to be thrown in, but unfortunately in the confusion of the brewday, it was missed out. Also, I accidentally burnt the polenta (corn grits) while chatting animatedly with SQ. 

It was an enjoyable brew day! On top of meeting my friends’ significant other, we totally binged on local food and beer. Due to the nature of my brewing workflow, I could unfortunately only involve them in the hot side of brewing.

Grain Bill
53.1% Pilsner Malt
17.7% Purple Sweet Potato
8.8% Polenta / Flaked Corn
8.8% Flaked Rice
4.4% Flaked Quinoa
3.5% Acid Malt

Hops
20g Tettnang @ 60 mins
20g Hallertau Mittelfruh @ 60 mins

Parameters
Mash Temp 66C
OG 1.051
FG 1.008
Bitterness 19 IBU

Sweet potato, rice, corn, quinoa - beer is a vegetable, indeed!  

The sweet potatoes (and polenta) were precooked to gelatinization temperatures so that the starch can be converted to sugars later during the mash.


Everyone helped - chopping the sweet potato up to increase surface area! 

Adding to the mash. Due to the very real possibility of a stuck mash due to all those adjuncts, I added 1L (by volume) of rice hulls. 

Yeast & Fermentation
Cream ales are traditionally fermented using ale yeasts at lager-ish temperatures (c.f. steam ales, which are fermented with lager yeasts at ale temperatures). Details aside, what it aims to do is to impart the light crispness of lager yeasts. 

A previous triangle taste test by Brülosophy suggested that W-34/70 maintains lager characteristics even when fermented at ale temperatures. For this beer, we actually used a mix of BOTH ale and lager yeasts - US-05 and Saflager W-34/70. (The real reason is because my W-34/70 has doubtful viability, so US-05 was thrown in as insurance!) The keg was hit was pure O2, then fermented at 17C. To prevent unwanted fruity esters from the Saflager 34/70, it was pressure-fermented using a spunding valve at 11 PSI.

To be continued ...
The beer has finished primary fermentation at this point. It is being slowly chilled to lager temperatures, before fining and filtering (aiming for a crystal-clear cream ale, if possible!), and finally lagering at close to freezing.