Gary Glass: Hi, I'm Gary Glass, Director of American Homebrewers Association. Today, I will be showing you how to conduct a batch sparge mash. We will be brewing Denny Conn's Milo's Alt recipe from the 2011 March/April issue of Zymurgy Magazine. This recipe features Munich Malt which makes it difficult to replicate using extracts.
This is a five gallon recipe with a 60 minute boil. A boil-off rate is about one and a half gallons per hour, so that means we need six and a half gallons from the mash into the kettle.
Don't worry if your volumes are off or your temperatures are off slightly, that's really no big deal. For subsequent batches you can use an online calculator or brewing software to dial in your system.
Our first step is to heat 3.
75 gallons of mash water to 168 degrees Fahrenheit. This will give us a mash thickness of 1.
37 quarts per pound. Okay, we are at 168 degrees Fahrenheit. Let's add our mash water to the mash tun. Now we will stir in our milled grains taking care not to disturb the bread and making sure to break up any dough balls.
Temperature is set on around 152 degrees Fahrenheit. Don't worry if you are off by a few degrees. If it's off by more than that, you can stir to cool it down or add boiling water to heat it up. Close the mash tun and let it sit for 60 minutes.
While the mash is resting start heating your sparge water. We have five gallons that we want to heat to 185 to 190 degrees Fahrenheit. This will raise the temperature of the mash to 165 to 170 degrees.
The mash has now rested for 60 minutes; we're going to test for conversion of sugars to starches. To do this, we'll take a small sample of the mash liquid and add a drop of iodine to it. If it turns black or purple, there is still starches present, let the mash rest for another 15 minutes and retest. If the iodine does not change color, conversion is complete.
When you've confirmed that conversion is complete, slowly open the valve on your mash tun and collect a pitcher or two of runnings, making sure the wort and the tube is clear of grain particles. Then gently return the runnings in to the mash tun. This recirculation filters the wort and settles the grain bed in a process known by its German name vorlauf.
Now fully open the valve of your mash tun and collect the runnings in the boil kettle. Once the mash is drained, close the valve, add your sparge water and stir the mash. Vorlauf and drain into the kettle, measure the volume in the kettle, if low, add the appropriate amount of sparge water to your mash tun, stir, re-circulate and drain. If high, increase your boil time to compensate.
And that's all there is to it, you can now proceed with the brewing process as you would any other batch you brewed.