We generally DO NOT recommend this feature for your mashtun. It is significantly MORE DIFFICULT to maintain mash temperature using a burner, and the risk of overshooting your target temperature is much higher. If you overshoot your target temp, you will de-activate the enzymes permanently and will not be able to make a fermentable wort, and thus a ruined batch of beer is what you will have.
What we do RECOMMEND is our standard mashtun design with insulating jacket. Our standard design is based on commercial breweries, which do not direct fire their mashtuns - this represents 95% of the world's breweries that do single infusion mash with only an Insulated Mashtun. The reason they do this is that it is simple, and effective, helps streamline production, and is much more "automated" and "set-it-and-forget-it" than messing around with a burner trying to pinpoint your target temp.
We offer this feature because we have received emails from many brewers that are being misinformed on brewing procedure by all those books, magazines and homebrew shops that recommend step mashes (which are NOT necessary due to today's fully modified malt). Step mashes can actually damage your beer using 99% of the world's malt, which is fully modified. The only known "undermodified malt" is Budweiser Budvar Pils...so unless you are a die-hard and need to use this, then the Direct Fired Mashtun Option IS NOT FOR YOU, and is SIMPLY NOT NECESSARY.
If you desire to mashout at higher temperatures, we recommend you use hotter sparge water to help liquify and rinse the sugars from the grain. A good target mashout temp is 168F. While it takes significantly hotter water to make the temperature of the grain and liquid in the mashtun rise, if the water is too hot (i.e. boiling), you can get astringent flavors leaching out from the husks of the grain and into your brew. Please read our article "infusion versus RIMS" which shows why it is not necessary to step mash anymore.
So, in summary, it is actually EASIER to brew using the standard insulating jacket (i.e non heated mashtun) and simply costs less. The DIRECT FIRED MASHTUN option is NOT NECESSARY unless you:
Desire to use Budweiser Budvar Pilsner (the only undermodified malt in existence)
Live in extremely cold climate and are concerned about maintaining mash temp.(In which case, you would be better off using our SUPER Mashtun Jacket which is proven to maintain mash temp within 1 degree over an 8 hour period!)
The Direct Fired Mashtun Option Includes:
Additional burner and needle valve located under mashtun.
Mashtun jacket is eliminated due to burner heat.
We cannot guarantee ease of use with a direct fired mashtun. If you choose to go this route, you should be prepared for problems related to hitting your target mash temps, maintaining those temps, and stratification of temperatures within your mashtun from the burner (i.e. the bottom may be much hotter than the top). On top of this, you will have to stir your mash constantly to redistribute the heat evenly throughout your mashtun, or risk deactivating enzymes.
In summary, we hope you understand why we offer this option - it is because we have received emails from misinformed brewers that want to do step mashes or regulate mash temp (which is completely unnecessary). Our goal is to educate you to brew better beer rather than sell you options you don't need, which is why we highly recommend you AVOID selecting this option. At the same time, we want to make sure that we do not turn away brewers that have their hearts set on a specific method of brewing, even if it is not the "right way". At any rate, a brewer that decides they do not like this option AFTER-THE-FACT, can always purchase a mashtun jacket and convert their BREWTREE back to it's intended design - a simple single step infusion mash with an insulated mashtun. Our original design is a PROVEN METHOD of making beer, and is the same method used in professional breweries throughout the world!
