Difficulty with Step Mashes

Last Monday night was a late night, a very late night.  Members of our local homebrewing club, the Charlottesville Area Masters of Real Ale, are preparing to refill the club's bourbon barrel.  Some readers may remember that our barrel soured unexpectedly on the first batch, an Imperial Porter (click here for posts about the bourbon barrel project).  There was not nearly the interest in the project now that the barrel was sour and for a while I feared it would become a planter.  But a few determined sour beer fans banded together, including one member who is brewing 20 gallons to hit the quota, and we are working towards the second fill.

The group selected the Flanders Red recipe out of the book, Wild Brews, by Jeff Sparrow.  If you look at the recipe, which is listed at the end of the post, you will note that it involves a multi-step mash.  Step mashing is a process that involves increasing the temperature of the mash in steps and holding each step for short periods of time.  Historically, step mashing was used because mash tuns were wooden vessels that could not be heated directly.  The temperature would be raised by adding specific volumes of boiling water and the process allowed brewers to consistently hit temperature ranges before the invention of the thermometer.  Step mashes can be very efficient when done properly, as they target specific enzyme sets and result in greater sugar extraction from the grains.  The can also set specific fermentability profiles for worts, though they are not required with today's highly modified malts.

The Flanders Red recipe listed a step mashing process that is based on the Rodenbach methodology.  It involves four steps (122 F, 145 F, 162 F, and 169 F) if flake maize is used.  I had never done so complex of a step mash before, so I joined forces with another brewer who had a kettle with a false bottom.  The plan was to use his kettle as a direct-fired mash tun and run the wort through a recirculation loop with my wort pump.  Then the mash could be heated to hit and maintain each mash step for the period required, all with little work on the part of the brewers.  Unfortunately, things did not go as planned.  The wort under the false bottom ended up boiling, which slowed the pull through to the wort pump and suddenly, we smelled the unmistakable aroma of scorched wort.  After dumping the mash out, and scrubbing the kettle vigorously, we elected to heat slower and stir constantly, which was more reliable.

In the end, we brewed 20 gallons of beer that night and it was a very memorable experience.  Even starting in the very early afternoon, we still got done after 1:00am in the morning, but it was the only day brewing could fit in both of our calendars.  The group is hoping to gather to fill the barrel with Flanders Red wort at the beginning of July.

If you ever find that you need to do a multi-step mash with a direct fired kettle, take the low-tech approach and stir while heating.  It provides a good arm workout and will avoid scorching if you stir diligently.

Cheers,

TW


Wild Brews Flanders Red recipe
50% Vienna
9% Carahell
9% Caravienna
9% Aromatic
3% Special "B"
20% Maize

Mash Schedule
Similar to Rodenbach
When using flaked maize, you can omit steps 1 and 3.
Assume 1.33 qts H2O/lb grain
1. Mash corn and 10% malted barley at 145 for 15 minutes.
2. Dough in grains and H2O to hit 122, and hold for 20 minutes.
3. Add adjunct mash to main mash.
4. Raise to 145 for 40 minutes.
5. Raise to 162 for 30 minutes.
6. Raise to 169 for 10 minutes.
7. Sparge with 176 H2O

Boiling Time: 2 hours

Bittering Hop addition: 10-12 IBUs.
Suggested hops: Hallertaur, Styrian goldings, E.K. Goldings
OG: 1.048 - 1.057
Fermentation: Wyeast 3763, Roeselare, at 68 for 1 week
Secondary: 80 for 8 weeks, or cellar for up to 3 years