Understanding the finer points of mash temperature is a way to take your homebrewing game to the next level. Let's dive into the fascinating world of mashing, where time and temperature play crucial roles in crafting the perfect pint. We have been experimenting with various mashing techniques and are excited to share our findings with you.
The Magic of Mashing: What Happens Behind the Scenes?
The goal of mashing is to allow the enzymes in the grains to convert the starches in the grains into fermentable sugars for our yeast to turn into alcohol. Grains are the seeds of the barley, wheat, and rye plants, and when we mash them, we are effectively tricking the seeds into growing into plants. But plants can't use starch for food either, so these seeds contain enzymes to do this for them. When brewing, this process is hijacked to grab the converted sugars so that alcohol can be made.
But what are enzymes? Enzymes can be thought of as a physical structure that helps chemical reactions occur faster. Think of them as the structure of a lock that holds the key in place so that the key is in the right position to reach the lock pins and allow you to turn the key to open the lock.
There are lots of different enzymes in the grains, and they all play different roles based on temperature:
|
Mash Stage |
Active Enzymes |
Activity Range (°C) |
Effect on Mash |
|
Cell wall structure breakdown |
Endoglucanase, beta solubilase, phosphatase |
40 – 53 |
Starch granules in the grains are protected by a cell wall which has to be broken down before the starch can be converted. |
|
Protein breakdown |
Endo-peptidase, carboxy-peptidase, amino-peptidase, di-peptidase |
45 – 50 |
At this stage of the mash the water-insoluble protein sheath is penetrated, allowing the starch to be reached. Protein molecules are broken down into their constituent amino acids which are necessary for healthy fermentation. |
|
Starch breakdown |
Beta-amylase, alpha amylase, limitdextrinase, maltase, saccharase |
35 – 75 |
Starches are broken down into fermentable sugars. |
Not All Grains are Equal
The above would make it sound like you could go into a barley field, pick some grains off the stalks, and brew with them straight away, but the grains have to go through some extra steps first. Therefore, maltsters get the grains from the farmers and malt them to make them easier for the brewer to use. They trick the grains into germinating (turning into a plant) by steeping them in cool water and allowing the seed to partially grow. The maltster then removes the rootles and dries the grain so that it can be shipped to the brewer. Maltsters discovered that by kilning, roasting and drying the grains in specific ways, they could create malts with enhanced flavour and colour contributions. However, due to the kilning and roasting, the enzymes in the grains were largely or completely destroyed.
This is why more than 50% of your grain bill needs to be a base malt. These malts have a high enough proportion of enzymes to convert all of their own starch and the starch of the unmalted, kilned and roasted grains in the grain bill. if you want to look into this further, you can look at the base malt's diastatic power (D.P.). The general rule is if the D.P. is greater than 40, then the malt will convert itself within an hour and would be good to use as a single malt beer. Otherwise, the higher the D.P. is, the better the malt will be at converting its own starches and other starches in the grain bill. For more information on single malt beers, check out Mastering the Single Malt and Hops Beer: SMaSH Brewing.
Time vs Temperature: The Great Debate
Brewers largely stick to 60 or 90-minute mashes, but why is this? Well, historically, brewers found that these mash times resulted in good yields and beers. The knowledge and fine-tuning of the malting and mashing processes have increased exponentially in the last 20 years and with modern malting, you might be surprised to learn that starch conversion can be completed in as little as 15 minutes of mashing at 65°C. For more information on Mash yield, check out Mastering Brewing Efficiency: Maximising Your Grain Yield.
However, the table above shows that different enzymes are more active at different temperatures. The two main enzymes brewers talk about to this effect are Alpha and Beta amylase. Alpha amylase makes slightly more complex sugars out of the starch, which are not as easily consumed by the yeast. So, the temperature range where alpha-amylase is most active is generally targeted for beers with a sweeter finish, like stouts. Beta amylase makes simpler sugars out of the starches, which are easily consumed by the yeast, resulting in drier beers. So, the temperature range where beta amylase is more active is generally targeted for beers with a drier finish, like American lagers.
Interestingly, higher mash temperatures reach maximum extract efficiency faster but plateau lower than longer, cooler mashes. This is because beta-amylase enzymes are more stable at lower temperatures, allowing them to work their magic for extended periods. In most recipe creation software, you will see a change in the predicted final gravity if you adjust the mash temperature. This final gravity being closer or further away from 1.000 gives us a feel for how dry the final beer will be.
You will also see there is much debate over a single steady mash temperature versus multi-step mashes. There have been many experiments, with just as many of them saying that there is a difference in the final beer as those that say there is no difference in the final beer. So, try out these methods and see the results they make on your beer.
Ready to Elevate Your Brewing?
Armed with this knowledge, you're now equipped to fine-tune your mashing process and create your own beers. Remember, brewing is both an art and a science – so don't be afraid to experiment and find what works best for your unique creations.
Happy brewing, and may your next batch be your best yet!
MYO Drinks
Helping you to make your own Great Batch from Scratch.