Why the Step Mash? The simple answer… to get better sugar extraction from your malt. Back in the days when you didn’t know how well your grains or malts were modified, it was suggested that you use several step mashes to get the most out of your malts. With the malts available today you do not necessarily need to do a step mash for the same reasons our forefathers did instead as a brewer, you have control over which enzymes you want to activate to get the body, mouthfeel, and head retention for your desired beer style.
Temperature, length, and consistency plays a major role in your mashing process which has an effect on your final product. Your step mash temperatures and styles is also a way for you to control your beer’s flavour, the sweetness, the body, and the viscosity. Before you have a panic attack, you do not have to do all these steps, simply mashing your malts between 64-68°C will suffice, these are just suggestions or guidelines for the curious brewers who feel like improving their brewing skills and knowledge.
Here are the simple step mash steps
Step Mash steps/rests
Strike Temperature
Gelatinization happens when the starch grains get in contact with heated water which makes the grains swell and burst making the starches more accessible to enzymes. This works better when the grains are in contact with water at a higher temperature thus your strike temp is higher than your mashing temperature.
Acid Rest 35-45°C
The acid rest helps to lower the pH in your wort to make it more acidic. This is useful when you are brewing a beer that contains a lot of wheat and oats in the mash bill.
Between 35-45°C the Beta-Glucans are broken down which helps to release more sugars and controls the viscosity.
Ferulic Acid Rest 43-45°C
If you are making a wheat-based beer and you want to get that clove-like aroma then this is an important part of the step mash (due to the 4-vinyl-guaiacol molecule). At this temp range, you release the ferulic acids. When making a beer that is not a wheat beer then ferulic acids could be considered an off-flavour in your beer.
Protein Rest 44-59°C
The protein rest should mainly be used with beers that have a lot of wheat and oats in them. The protein rest will help with head retention and the body of the beer by breaking down the protein chains. This will also help with the protein haze that you will find in your beer. Do not use this step in beers that have well-modified malts as it can reduce your head retention and body.
The Saccharification Rest
The average mash step is 65°C. This is because between 61-71°C your starches are being converted into sugar.
Alpha-Amylase is most active between 68-72°C (for a sweeter beer)
Beta-Amylase is most active between 60-63°C (for a drier beer)
Mash Out
To stop the conversion process in the Saccharification rest we do a mash-out that denatures the enzymes. When you are mashing out your wort you should keep the temperatures between 75-78°C, if you go over 78°C you risk the chance of your beer having an astringent flavour due to the tannins released from your grains.
Conclusion:
For desired flavours and enzymes to be activated and proteins to be settled, it is important to choose the right temperatures to mash your specific grain bill. There are many tricks and traits so find which one suits your brewing system best. Many experts say that they can’t taste the difference between the different mashed beers and some say they can, so in my opinion… experiment and find out for yourself!