April 16, 2025
How to Perform a Cereal Mash (Step-by-Step)
Working with raw grains like corn, rice, oats, or barley? If they’re not flaked, malted, or pre-processed, you’ll need to bust out a cereal mash. This time-tested technique softens up those stubborn starches—making them ripe for enzymatic conversion and perfect for fermentation. In short: it unlocks flavor and fermentables your yeast craves.
What Is a Cereal Mash?
A cereal mash is a two-phase prep method where raw, unmalted grains get cooked (aka gelatinized), then combined with your main mash to convert starches into sugars. These raw grains keep their starches locked up tight in granules, and you’ll need heat to break them free before any enzymes can get to work. Think of it as the warm-up act that makes the headliner shine.
When Do You Need One?
If your grain bill includes raw corn, rice, or oats—basically anything that hasn’t been malted, flaked, puffed, or pre-gelatinized—you’re in cereal mash territory. If you’re rolling with flaked maize, malted grains, or quick oats, congrats: skip the cereal mash and carry on.
Grains that need a cereal mash:
- Raw or cracked corn (maize)
- Whole rice
- Raw oats
- Unmalted barley, wheat, or rye
- Heirloom grains in raw form
Grains that don’t need one:
- Flaked corn, flaked rice, flaked oats
- Malted barley, wheat, rye
- Quick oats (instant)
- Torrified or puffed grains
Gelatinization Temperature Ranges
Every grain has a sweet spot where starches break down and get gelatinized. Here's your cheat sheet:
| Grain | Gelatinization Temp (°F) | Gelatinization Temp (°C) |
|---|---|---|
| Unmalted Barley | 140–150°F | 60–65°C |
| Wheat | 136–147°F | 58–64°C |
| Rye | 135–158°F | 57–70°C |
| Oats | 127–138°F | 53–59°C |
| Corn (Maize) | 143–165°F | 62–74°C |
| Rice | 154–172°F | 68–78°C |
Step-by-Step: How to Do a Cereal Mash
- Mill it fine: Crush your raw grains to a finer consistency than your base malt to help with gelatinization.
- Mix in enzymes: Add 10–20% malted barley to your raw grain—this brings in the enzymes needed for conversion later. Traditional 10% 6-row or 20% 2-row malted barley.
- Infuse with hot water: Use 2–3 quarts of water per pound of grain. Hit the gelatinization temp range based on your grain (see chart above).
- Hold the temp: Keep it in that range for 15–20 minutes, stirring occasionally to avoid scorching.
- Bring to a gentle boil: Boil for 20–30 minutes. This fully gelatinizes the starches—essential for raw grains like corn and rice—and transforms your mash into a thick, gooey, enzyme-ready slurry.
- Add to your main mash: Either cool the mixture to your mash rest temp (148–156°F) or use it hot and calculate your strike temp to compensate.
Why Bother?
Flaked grains are great, but there’s something deeply satisfying about taking raw ingredients and doing it the old-school way. Cereal mashing opens the door to heirloom corn, garden-grown barley, and experimental brews with real rustic charm.
Fire Up the Kettle
Want full control over flavor and fermentables? Ready to make your next Kentucky Common or farmhouse ale from the ground up? You’re officially equipped to mash like a pro.
