When I noticed the thermometer in my basement read 50˚F (10˚C), one thought popped into my head: Lager Time. Finding (or creating) a space to ferment beers at lager temperatures is a challenge. Bringing wort down to lager pitching temperature quickly and easily can be a bigger challenge. I’ve found a way to deal with that challenge in a fairly inexpensive and low-tech way.
My immersion chiller does a good job of knocking most of the initial heat out of near-boiling wort. But, at a certain time, the temperature reaches a plateau where the chilling slows down. The level of that plateau varies, depending on the season and the temperature of the ground water.
The trick to the method that I use is to circulate ice water through the immersion chiller using a cheap immersible pond pump from the local hardware store. This is even more effective than adding a second pre-chiller that is immersed in ice water, which I have tried as well.
I chose a pump that is under $30.00 that has a flow rate of around 130 gallons per hour (492 liters per hour). It took a little searching in the store to find hose and connectors to transition from the small pump outlet into the garden hose fitting of my immersion chiller. Your types of connectors may vary, depending on the type of pump and chiller you have.
Using the setup is simple. I use an infrared thermometer to monitor the temperature of the wort as it chills. Usually about half an hour into the chill, the chilling rate starts to slow down dramatically. That’s when I put the pump into a small picnic cooler and fill it with ice. While the immersion chiller is still hooked up to the tap, I direct the chiller outflow on top of the ice to create some ice water that the pump can start using. I then shut off the tap, connect the chiller inflow to the pump, and put the chiller outflow tube into the opposite side of the picnic cooler from the pump.
When I plug in the pump, water that is near freezing temperature starts to flow through the copper chiller. The wort temperature begins falling again. I found when I brewed yesterday that I could go from near boiling to 50˚F (10˚C) in about an hour.
To help the wort chill more quickly, you should agitate the chiller coil in the wort. Be careful in the beginning. The outflow of the chiller will be quite hot.
This is a great method to use in summer for those of us who live in warmer latitudes. When our ground water warms, it’s a challenge to get wort down even to ale pitching temperature.
Here’s the recipe I brewed this week.
Easy Peasy Pilsner
5 gal. (19 L) Batch
11 lb. (4.9 kg) German Pilsner Malt
Single infusion @ 150˚F (65˚C) for one hour
2.0 oz. (56 g) Czech Saaz pellets (90 min.)
1.0 oz. (28 g) Czech Saaz pellets (flameout)
Saflager S-23 dry yeast (2 pkg.)
OG: 1.048 FG: TBD