In my last post American Lager, BJCP A1 and 1B, I promised that I would describe the dilution and packaging process used to transform a high ABV American Lager base beer into full kegs of American Light Lager (1A) and American Lager (1B). I packaged 1A and 1B on Sunday, February 17 2019, approximately 3 weeks after brew day, so here it is.
I began the process by heating 25L of very soft, Langley BC tap water to a boil in my Grainfather. I boiled the water for two reasons. First, to sanitize the water and second, to remove as much oxygen as possible in an effort to prevent oxidizing the beer during the dilution process. Before the water was boiling I added 0.5 grams / 20 ppm of sodium metabisulphite to neutralize any chloramines present in the tap water and also to further scavenge any oxygen left over after the boiling process.
While I waited for the Grainfather to bring the water to a boil, I took a gravity sample. I was pleasantly surprised to find that the base beer had fermented out to 1.010, a full 4 points lower than I was expecting. In my last post I had mentioned I was worried that my choice of Wyeast 2007 would not attenuate the 1.072 wort sufficiently, as it is not known to be a high attenuating strain. However, it seems that the large proportion of maltose from the converted rice sugars helped to drive the attenuation down and this resulted in a 8.1% ABV base beer. I should also mention that the sample tasted pretty damn good, what I imagine an Imperial Classic American Pilsner would taste like, and I almost regret not kegging up the beer as is!
With the ABV of the base beer now known, I proceeded to calculate the ratios of water to base beer needed to make 1A and 1B. Plugging the numbers into Excel and using the formula
ABV = ABV_base_beer * (Amount_base_beer/ (Dilution_water + Amount_base_beer))
I figured out I needed 9.5 L each of base beer and water for a full keg of 1A at ~4% ABV, and 12 L base beer diluted with 7 L of water for a full keg of 1B at ~5.1 % ABV.
The dilution water was boiled with the lid off for 10 minutes and then re-circulated for an additional 5 minutes through the Grainfather counter flow chiller to sanitize the hardware and silicon tubing. I then ran cold water through the counter flow chiller to drop the temperature of the water in the grainfather down to 14C. Due to the relatively low flow rate of the Grainfather pump, this process took around 25 minutes, which was longer than I thought it would take. Thankfully, the water exiting the chiller was much colder than that, around 39.2F / 4 C. Coincidentally, the mass of water at 4C is almost exactly 1 Kg / L, and so I was easily able to weigh out the required measures of water into each keg using my trusty Cabela’s scale. Each keg had been thoroughly cleaned, sanitized, filled with Star San and fully CO2 purged the night before.
I then proceeded to fill each keg to the top with the 8.1% ABV base beer. To each keg I added approximately 10 ppm sodium metabisulphite solution to further suck up any oxygen that may have been introduced during the water and base beer additions. I attached the lids, gave each a quick CO2 purge for good measure then placed the kegs in my beer fridge to drop the temperature to around 34 F / 1 C. Later that evening, when the beers were cold, I fined them with gelatine to drop out the chill haze and started force carbonating them. My hope is that beers will be brilliantly clear and ready for presentation after a couple of weeks of lagering.
The irony is not lost on me as I ponder the great lengths I’ve gone through to try and make these reduced flavour American Lager beers. They are easily twice the effort to make as “normal” homebrews, and one could argue that the amount of work required to make these beers at home is simply not worth the end result. However, that would be completely missing the point of why I homebrew; it’s the process, learning and challenges along the way that keeps homebrewing interesting to me. We’ll see if I hit the 1A/1B style parameters in the upcoming BOTY competitions, stay tuned.