D-lite Festbier
ALL-GRAIN
Batch size: 5 gallons (19 liters) Brewhouse efficiency: 72% OG: 1.052 FG: 1.012 IBUS: 18 ABV: 5.3%
MALT/GRAIN BILL
10 lb (4.5 kg) Weyermann Extra-pale Premium Pilsner 0.4 lb (181 g) Weyermann Carafoam Calcium carbonate and calcium sulfate 3:1 to 50 ppm calcium, according to your water profile
HOPS SCHEDULE YEAST 1.5 oz (42 g) Tettnanger [5% AA] at 20 minutes
Lots of Saflager W-34/70 Lager Dry Yeast, White Labs WLP830 (German Lager), or Wyeast 2124 (Bohemian Lager).
A two-step starter of 2 quarts (1.9 l) to 1 gallon (3.8 l) should give you enough from a healthy package of liquid yeast. Or simply spring for four packages to ensure a quick and full fermentation.
DIRECTIONS
Dough in with 13 quarts (12.3 l) water to hit 150°F (66°C) for 60 minutes, then add 5.5 quarts (5.2 l) of boiling water to mash out. Vorlauf and lauter as usual but keep in mind that your boil off will be about 25 percent of normal. Either collect only 5.5 gallons (20.8 l) or plan to have some extra beer. Then hold the wort in the boil kettle as close to 170°F (77°C) as you can (lid off!) for 100 minutes. Bring to a boil and add the single hop addition. (Feel free to substitute an equivalent IBU of your favorite low-alpha German hop.) Shut it down after 20 minutes of rolling boil.
Chill the wort rapidly to slightly below fermentation temperature, about 50°F (10°C). Aerate the wort and pitch the yeast.
Hold the temperature as close to 50–52°F (10–11°C) as you can for 2 weeks before slowly lowering it to 36–38°F (2–3°C) and transferring to secondary for a 3-week lager. Package as usual.
BREWER’S NOTES
In my experiment, acidulation was done with lactic acid, but you can also replace some of the Pilsner malt with Weyermann Acidulated malt. You should be able to move ph down about 0.1 with each percent of the grist.
To chill this wort quickly, you’ll want to pull out all the stops. Keep in mind the current temperature of your groundwater! If you have an immersion chiller, combine it with an ice bath and near continuous stirring to reach that 100°F (38°C) mark. I’ve seen this happen in as little as 12 minutes in the summer. Running an immersion chiller in an ice bath as a prechiller for a plate chiller will allow your wort to run very fast and also give an excellent cold break. leave behind a measurable amount of DMS to contribute any reduction to the length of time in the “DMS rest.”
The resulting beers were (understandably, given the short boil time) all impressively light in color, but would they be drinkable? Table 2 shows the results, again run through New Belgium’s lab. As you can see, the longer the wort was allowed to stand pre-boil, the greater the reduction of DMS in the finished beer. Although most tasters would detect DMS even in the sample with the lowest DMS level, the variance among them is wonderfully telling.
The final test is, of course, to produce an actual beer using both a conventional lauter and 90-minute boil and using a 100-minute DMS stand and a 20-minute boil time (chilling them much faster!) and compare flavor and color development. Look for the follow-up report in “A Novel Approach to DMS Reduction, Part 2.”
My theory (based on the evidence) is that given a direct-fired boil, letting the hot wort stand beforehand will still allow dramatic DMS production and volatilization with a very minimal boil time and should produce the lightest color possible on a given system.
It would be interesting to further investigate the time needed to generate 100 percent of the available SMM-TO-DMS and then just how short a boil is necessary to be rid of it. It’s feasible that given enough time before and during boil, the problems of a slower chill method could be greatly mitigated. Lucky for us, there is always more research to be done!
Until then, if you like the idea of an impossibly light colored beer—the D-lite Festbier recipe (left), for instance—consider a DMS stand on the lightest-kilned malt you can find and chill it as near instantly as you can. I’m certain it will be “d-liteful.”