How to Step Mash in the BREWHA BIAC

Step mashing is a technique that can help you achieve greater control over the flavor profile and characteristics of your beer. In this guide, we will explore how to step mash in the BREWHA BIAC to create complex and unique brews.

What is Step Mashing?

Step mashing is a method used in brewing to raise the temperature of the mash through a series of rests at different temperature ranges. By following a specific temperature schedule, brewers can activate different enzymes that break down complex sugars into simpler sugars, ultimately influencing the body, mouthfeel, and fermentability of the beer.

Step Mashing in the BREWHA BIAC

The BREWHA BIAC (Brew-In-A-Conical) system is a versatile all-in-one brewing system that allows for precise temperature control, making it ideal for step mashing. To step mash in the BREWHA BIAC, simply program the controller to ramp up the temperature in stages according to your desired mash schedule. 

In order to raise the temperature of the mash more than a few degrees as is required for procedures such as step mashing, or if your grain bed is several degrees below your target temparture, it is necessary to raise the temperature of the recirculating water/wort significantly above the target temperature. The reason for this is that the temperature of a large amount of low temperature water or wort (i.e., the mash in the Colander) cannot be changed quickly by a small volume of water (the recirculating water) at only a slightly higher temperature. It is a relatively simple relationship between the volume and temperature needing to be heated, and the volume and temperature being added; the heat will average out. So, for example, to raise a 100L/25USG mash 10°C/19°F by recirculating 25L/6USG, the 25L/6USG needs to be 40°C/76°F in order to raise the total 10°C/19°F. Calculations need to be made to determine the temperature of the recirculating water and the time to raise the temperature. (Note: Grain is a fairly efficient insulator, so heat under the Colander will not heat the grain bed up—there needs to be circulation.)

To raise the temperature of the mash quickly, rather than through gradual heating of recirculating wort, a technique similar to decoction mashing (where a portion of the mash is removed, heated, and then added back in) can be used, in which the pump should be turned off and the water in the cone below the Colander raised to the calculated temperature (to a maximum of 95°C/200°F). Then the pump is started again and the heated wort is circulated up into the Colander where it will raise the temperature of the mash. If the calculations for a given temperature rise require a volume greater than the cone volume (see Table E for cone volumes), two steps are needed: first, the temperature below the cone is kept at the target temperature until the volume recirculated AND the volume in the cone equals the calculated volume; then the temperature is set to the new step temperature while recirculation (to empty out the hotter wort in the cone) continues. (A maximum temperature of 95°C/200°F is recommended, as heating any higher will likely cause foaming up the sides of the Colander; if this starts to occur, lower your maximum temperature.)

Fortunately (unless you love math) programs like Brewfather and Beersmith have a decoction calculator that gives the amount of water needing to be recirculated. In the Beersmith example shown in the picture to the left for the 5BBL (6hL) brewing system, with a temperature rise from 60°C to 65°C (131-140°F), a strike volume of 5BBL or 575L (100L in the cone and 475L in the Colander) and 300lb of grain, the calculator indicates that 100L at 93.2°C are required. To achieve this, with the pump off, heat the area below the Colander to 93.2°C/200°F. Then start the pump and circulate for 10 minutes at 10L/min, keeping the wort in the cone at 93°C. At this point, one will have put 100L/26USG of 93°C water/wort into the Colander. If the calculator says a larger volume is needed, for example if the step temperature is larger, this can be repeated a couple times. Once the step is completed, then set the temperature controller back to a target temperature of 65°C/150°F and continue recirculating. The temperature in the cone will gradually drop as the wort from above cools it, and the temperature in the Colander will rise. After 20–30 minutes the mash should be very close to the target temperature. (As with decoction mashing, it is important to keep the mash pH at the low end of normal—close to 5.2—in order to minimize any tannin extraction.)

Benefits of Step Mashing

Step mashing offers several benefits to brewers, including:

• Enhanced enzymatic activity for better sugar conversion
• Improved fermentability and attenuation
• Control over body, mouthfeel, and sweetness of the beer
• Development of complex flavors and aromas

Step Mashing Tips

Here are some tips to help you master step mashing in the BREWHA BIAC:

• At lower temperatures (similar to cold mashing) it is important to keep the heater output at much lower levels, as the solids that are present (starches) in the wort break down much slower, and are therefore at much higher risk of sticking to the heater and causing scorching. It is recommended during standard mash to keep heater output at or below 50% and to lower the output further as temperature drops. So for 50-60C (120-140F) it is recommended to keep the heaters at or below 35%, 40-50C (104-120F) at  20%, and below that (like in cold mashing) at or below 10%. With more gummy cereals (rye, wheat etc.) it suggested to go lower.
• Practice test batches in your pilot system before scaling up
• Plan your mash schedule in advance, taking into account the characteristics you want in your final beer.
• Monitor the temperature closely during each rest to ensure accuracy and consistency.
• Adjust the mash schedule based on the style of beer you are brewing and the desired outcome.
• Take notes during the process to track the results and make adjustments for future brews.

Experiment and Explore

Step mashing in the BREWHA BIAC opens up a world of possibilities for creating unique and flavorful beers. Don't be afraid to experiment with different mash schedules, temperatures, and ingredients to discover the perfect combination for your next brew. With practice and patience, you can master the art of step mashing and elevate your brewing game to new heights.