Brewing with cereals
There are many reasons why brewers use various flaked grains. Some intensify a certain characteristic, add a unique aroma to the beer, while others affect the color and clarity or boost the volume of fermentable sugars. Depending on the beer style and purpose you can commonly choose among flaked maize, barley, oat and wheat. Their production method starts by steam-cooking, then they rolled flat between hot cylinders and finally dried. The heat and pressure pre-gelatinize the starch, so they can simply added directly to the mash. Depending on the grain the addition may occur at beginning of the mash, or you can perform a protein rest, if needed. Flaked grains are not malted at all, therefor do not include any enzymes to break down their starch, but luckily they can utilize the enzymes from the barley. Nevertheless brewers have to be careful of their ratio and how to compose the rest of the grain bill.
There are many different forms of corn you use in your grist bill. Flake is the simplest one of them. As it only has a little protein no such rest is required. It’s generally pregelatinized too, so you can directly add to your mash with all other grains and schedule your brewing as usual.
Result: milder taste; dry, crispy finish
Flavour: sweet, less malty
Uses: usually in lighter Pilsners
As whole grains require a long gelatinizing process brewers usually choose the flaked version. Increases the volume of fermentable sugars, without any additional body or taste. You can expect some extra haziness above 10%, consider this when brewing a low EBC beer.
Result: stronger head retention, smoother flavour
Flavour: slightly grainy
Beer styles: Stouts
They can be added up to 20% to the mash, but with 10% you can easily reach your aim. Excess in glucans results in extra body and texture, which could affect filtration too, therefore more rice hulls are needed. The form you can normally buy is pregelatinized, so no protein rest is necessary.
Result: additional body, foam retention and haziness
Flavour: silky mouthfeel
Beer styles: Oatmeal Stout, Porter, Witbier, New England IPA
Flaked version of wheat imparts more “wheaty”, flavour than the malted one. They are high in protein, therefor increase haziness. Having a protein rest is recommended due to the excess in beta-glucans and also to help the starches be easier gelatinized.
Result: increased body and head retention
Flavour: spicy, bready
Beer styles: Witbier, Weizen, New England IPA