Breaking News - All About Steinbier by John Adams
February 27, 2000 -- John "Brews Traveler" Adams revives the ancient brewing technique of mashing with hot rocks
Three soldiers come into a town tired, cold, and looking for food. When no one in the town would help them, they invited the towns people to partake in Stone Soup...
Brewing a Steinbier is a fun way to take brewing in a more advanced (and backward) direction. Attempting to use hot rocks to furnish the heat for the boil and/or mash makes a traditional recipe more challenging and unique.
The History -
Steinbier, contrary to popular belief, is not a style as much as it is an ancient procedure for heating the wort. Before brewers had metal pots, they used wooden pots to cook in. Since they could not directly heat the wood, they added the heat source, hot rocks, into the pot.
Once the brewer was accustomed to the heating potential of each individual rock, hitting the proper temperature was easy.
The Style -
While not truly a style, there are certain stylist profiles that this technique lends. The two predominant ones are a caramelized malt and smoky flavors.
While the amount of heat energy in each rock is small and it takes a fair number of rocks to raise the temperature of the wort, the heat of the rock does scorch the wort that comes in direct contact. This caramelizes the sugars leaving a camel sweetness behind.
When the rocks are taken from an open fire and added to the wort, the soot and burnt-wood flavors from the rocks are washed into the liquid giving the beer a slightly smoky character.
What You Need -
In order to produce a steinbier you need a few extra items: rocks, a high-temperature heat source, and a method to safely move the heated rocks from the fire into the brew pot.
The Rocks -
It is very important to use a rock that (1) can take the thermal shock of being heated and cooled and (2) will not interact chemically with the wort itself. It must stand up the to acidity of the wort and the temperature changes of rapid heating and cooling while not altering the pH of the wort.
Rauchenfels, the original Steinbier producer, uses graywacke. Graywacke's chief advantage is its ability to bloom, or expand, when heated. This creates additional surface area for sugars to become trapped and caramelize within.
Graywacke is a dark-colored, strongly-bonded sandstone containing feldspar and quartz. Graywacke can be found in the Pacific Coast ranges of the northwest US, the Alpine flysch of Switzerland and France, and the Italian Apennines.
If you are unable to obtain graywacke, Chuck Skypeck of Bosco's suggests pink granite, an igneous rock. While it does not bloom as graywacke does, it is easier to find and can be used for several batches before it cracks apart into smaller pieces.
Whatever rock you choose, it is very important to make sure the rock itself does not have any trapped water within (i.e., a river rock). If the rock has trapped water, it will pop like corn when heated (but far more violently).
The Heat Source -
The ideal heat source for steinbier is a fire in which you can place the rocks in the coals. In order to get the fire hot enough you should use good dry, hot burning hardwood (oak, cherry, or beechwood) as the fuel.
You will also need an oxygen source to keep the fire hot. An electric fan will do the job of a bellows. I suggest purchasing a cheap fan and expecting it to melt or at the very least get soot in it. Depending upon the air flow and how close it is to the fire (not too close as to catch fire), it may not survive to see the second batch.
If you have a tank of compressed O2 (welding, not hospital grade) this would also do the trick. This is possibly a more expensive alternative to using a fan, and one should be more careful when attempting it as to avoid placing the tank too close to the fire.
Instead of building a fire, I have also used my propane burner to heat the rocks. The advantage of this method should be obvious; the amount of effort required is far less. However you will lose the sooty/smoky flavors contributed by the open fire. Depending upon your burner, heating the rocks will take far less time.
Handling the Rocks -
While brewing this kind of beer is fun, being safe is the single biggest concern. Keep in mind that you will be stoking a fire and keeping it cherry red for a long time. You will be placing rocks into it which may crack (or even explode). You will be transporting the rocks from the fire into the brew pot in which they will go through a very rapid cooling period creating a highly agitated and vigorous boil.
One must be careful when carrying the rocks from the fire to pot. The uneven surface of the rocks and their size makes them difficult to grab hold of with a tool. While it may seem straight forward to grab them with a tool (e.g., a log turner or tongs), it is easier said then done.
There are three good methods I suggest to move the rocks. The first is to heat the rocks and then to place them in some sort of carrier (depending upon your carrier, you may heat it too). When the rocks need to be moved you simply move both the carrier and the rocks. For carriers, I have seen brewers use empty kegs (for very large batches); a stainless-steel colander or fry basket would also work.
The second method is the tea-bag approach. I have taken thick, high-quality, stainless-steel wire and wrapped each rock repeatedly to make a tea-bag out of each rock.
This has a few advantages: (1) it keeps the amount of non-rock material that will be immersed to a minimum; (2) when wound, the wire helps to hold together large fragments that may crack off; and (3) splashing is minimized when adding the rocks to the wort.
Be sure to use lots of wire thoroughly (it too may fatigue and break) and to wear gloves when handling the wire it will get very hot even when four feet long and out of the fire!
The third method is to use a shovel to extract the rocks from the fire when ready. Be careful when adding the rocks into the pot to minimize splashing. The shovel keeps you at arms length from the heat and will not become hot as the wire does. It chief disadvantage is the difficulty of removing the rock from the pot when all finished (I don't recommend putting the shovel into your brew pot).
The Procedure -
Preparation - Before you begin your batch you should remove as much dirt as possible from each rock. A good low-soap washing with a scrub brush is in order. If you plan to keep the rocks in a secondary fermenter you might consider an acid wash as well to remove or kill any lichens, mosses, or other organisms living in the rock.
You should also consider testing the rock to see if it can withstand the thermal stresses of heating and cooling. Afterwards leave your rocks in the pot and boil them for one hour to remove any remaining residues and more fully sanitize the rocks.
This is also a good time to get the feel for the thermal characteristics of each rock. To do this, heat the rock using a propane burner and then immerse it into 6.5 gallons of water. Measure the temperature change before and after you added the rock allowing enough time for the water to absorb the heat.
Mashing -
Using hot rocks to control the temperature is probably reserved for the more experienced Hot Rocker since it takes more effort and patience. Once you have gotten the hang of heating the rocks and getting the wort to boil without a flame, then you can begin using the rocks to help the mash temperature.
This procedure is no different than boiling the wort with the expectation that using the rocks to hit a specific mash temperature is obviously more difficult. This first time you attempt it, just use the rocks to facilitate a decoction and get the mash to boil. After you get the hang of it and understand the thermal properties of your rocks, try to do the entire mash with rocks.
One of the advantages of this method is that you get more sugars (and grains) coated on each rock. After you're finished with the mash, put the rocks back into the fire. This will burn the sugars and give the beer a smokier/burnt character.
Boiling -
In order to understand how much rock is required to raise the temperature of the wort a little physics is handy (there will be a test at the end of this article). The specific heat of wort is close to water, we'll say 1.05 (J/kg°K) and the specific heat of granite is 0.19. The equation for calculating heat capacity is:
Mass * Temperature change * Specific Heat.
Here is the breakdown of thermal masses for 6.5 gallons of wort at various temperatures:
Wort (6.5g) |
Rock |
Temp
°F |
Temp
°F |
Weight
lb@600°F |
Weight
lb@700°F |
130 |
212 |
63.4 |
50.4 |
150 |
212 |
47.9 |
38.1 |
170 |
212 |
32.4 |
25.8 |
I have found a melon-sized piece of granite weights approximately 5 pounds. In order to raise the temperature from 150 to boil we need 38.1 pounds of 700°F rock or roughly 8 rocks!
Do your best to try and get the wort to boil, keeping in mind that the important thing is to get the rocks to boil/bake the wort's sugars until caramelized. It is this caramelization that gives steinbier its unique character.
When you add the rocks to the wort they will split, rubble, and growl. After a minute, remove them allowing the sugars from the wort to bake onto their surface before immersing them again. Do this repeatedly until a dark glossy appearance is formed.
Rinsing -
The sugars that coat each rock give the beer its unique character and need to be reintroduced into the beer. There are three methods to choose from to accomplish this: keeping the rocks in the boil; placing the rocks into the secondary fermenter; and rinsing the rocks before bottling.
The first method is to leave a few rocks in the boil. The caramelized sugars will have plenty of time to rinse off in the boiling wort. This method works best when you mash with the rocks and the rocks have plenty of caramelized and burnt sugars.
The second method requires placing the rocks into the secondary for a few days. This requires careful handling and storage of the rocks to avoid having any air-born yeast from getting a foothold. The last thing you want to do is to contaminate your beer after all of your hard work.
The final method is a simpler version of the former. Fill a small container with your beer just prior to bottling. Place the rocks in the container for a short time allowing the beer to gently wash away the sugars. You will want to refill the container a few times while keeping the contact time relatively short.
In Conclusion -
This is a very fun beer to brew and with a little patience and experimentation you can be very successful. Brewing steinbier is more of an art form than a science so don't expect each batch to taste like its predecessor.
This is also an excellent opportunity for your entire homebrew club to participate and enjoy in, what I believe is, the funnest brewing procedure. Make sure that you have lots of good food, good beer, and good friends on hand and a great time will be had by all!
Commercial examples -
Rauchenfels Steinbier Privatbrauerei Franz Joseph Sailer Marktoberdorf, Germany
Bosco's Famous Flaming Stone Beer Bosco's Brewery and Pizzeria Memphis and Nashville, Tennessee
Brimstone Stone Beer Brimstone Brewery Baltimore, Maryland
Stone Fired Ale Maritime Beer Company Inc. Halifax, Nova Scotia
Additional reading -
Rahn, Phil & Skypeck, Chuck (1992). "Flaming Stone - Brewing Traditional Steinbiere". Zymurgy, (Vol. 15, No. 5), pp. 30-32.
Rahn, Phil & Skypeck, Chuck (1994). "Traditional German Steinbier". Zymurgy, (Vol. 17, No. 54, pp. 16-18.
Stevens, Mark (1994). "Rekindling Brewing Traditions on Brewery Hill" . Brewing Techniques, (Vol. 5, No. 4, pp. 72-81.
Stewart, Hank (1999). "Marketing the Stone". American Brewer Magazine, (No. 79).
Recipes and Photo Galleries -
Hot Rockin' Steinbier - by John Adams
http://www.adamsco-inc.com/BrewsTraveler/Main/recipes/ales/steinbier/hotRockin/
Stone Groove - by Mark Stevens http://brewery.org/brewery/gambmug/recs/83.shtml
Sizzling Steinbier http://www.skotrat.com/skotrat/recipes/special/smoked/recipes/6.html
Brewing the KROC Hot Rockin' Steinbier
http://www.adamsco-inc.com/BrewsTraveler/Main/reports/1999/KrocHotRockin/
Bloatarian Brewing League group brew
http://hbd.org/bloat/steinpics.html
- Hot Rockin' is a trademarked name.
Copyright 2000 - John Adams
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