Stein Brewing: What Happens When You Mention Beer-making to a Geologist

Stein Brewing is an ancient method of brewing beer that brewers used when they did not have wide access to metal pots. Before metal pots, brewers used wooden or clay vats, but they could not put the clay or wood pots in the fire to boil the liquid (“wort” in brewing terms). Since the liquid could not be brought to the heat, the heat had to be brought to the liquid. In lieu of fire, brewers heated stones and added them to the liquid in the vessel to make it boil. It was labor intensive and dangerous, but beer was so important to the society at the time (and, as some would argue, still is) that it was worth the effort. The process adds a distinct character to the finished beer, a sort of smoky caramel flavor that only happens from rapid, high-temperature heating of the sugars in the wort. This ancient beer taste is missing from modern beer, … until you mention home-brewing with rocks to a geologist.

Not only will we capture that long-gone taste, but brewing beer by the Stein Method adds a fun story and good time to your brew adventures. For this beer, we chose a recipe that is half-way between an Irish Stout (like Murphy’s) and an American Stout. It took about 5 hours to make and made for a fun afternoon. The goal was to choose a recipe or type of beer that would benefit from the caramelization of the wort from the hot diorite.

The ingredients:
Barley, malt, and crystal comes from the Brewers Supply Group:
9 lbs of American 2 Row Barley,
1 lb of Roasted Barley,
1 lb of Flaked Barley,
4 oz of Chocolate Malt,
4 oz of Crystal 60,
4 oz of Simpson’s Double Roasted Crystal,

1.5 oz of Nugget Hops from Niko Brew (11.1% Alpha Acid – to make the beer bitter)
-added at the beginning of the 60 minutes of rock boiling.

1 packet of US-05 Ale Yeast.

About 1-2 cups of cold brewed Dean’s Beans NoCO2 Peruvian coffee will be added to a portion of the finished beer.

Equipment came from The Brew Bag and The Weak Knee Homebrew in Pottstown Pennsylvania.

Rocks came from my farm (Triassic Diorite).

The large metal tongs came from the Ingalls Iron Works in Verona, Pennsylvania (where my grandfather worked – I’m sure he was smiling in heaven all day for us).

To prepare the wort for rock boiling, we mashed in (ie added the ingredients to the water) at 154 degrees F, using Brew in A Bag, heating the strike water with propane so we could achieve an accurate temperature. We could have used the hot rocks here, but that would not have added anything to the taste because it was just water. After an hour of simmering, the wort was ready.

Meanwhile, we heated diorite (the rocks) over a fire for several hours, using anthracite coal (from PA of course!) to get the fire hotter than with wood alone. Man, it was hot! After some discussion, we decided to dip the hot rocks in a bucket of clean water before adding them to the wort in order to remove most of the ash. The first round of rocks brought the wort to a simmer and I honestly thought we were going to have to use the propane burner to achieve a full boil. But the second round of rocks did the trick, working so well it caused a boil over. We used the steaming basket that came with the pot to easily remove the rocks from the wort once the boil died down and kept rotating in hot rocks for 1 hour.

We ended up with 6 gallons of the boiled wort (1.047 specific gravity – which indicates the amount of sugar present) which is now fermenting as you read this. In about a month, we’ll taste it and determine the success of our first Stein beer adventure. Hopefully, it is tasty, but will definitely be something you can’t buy in a store, and a really good story to share as well.

Here is a video of putting a hot rock into the wort (click on the “Stein Brewing” below):
Stein Brewing