If you are getting into all-grain brewing, sooner or later you are going to hear someone talk about doing a mash out.
And if you are anything like most beginner brewers, your first thought is probably:
Do I actually need to do this?
Short answer?
No, not always.
But it is still worth understanding what a mash out is, what it does, and why some brewers include it as part of their all-grain brewing process.
I filmed this video while brewing my Tropical Thunder Blonde Ale on the BrewZilla, and it was the perfect time to show the process in real time.
VIDEO
(Coming soon)
If you are brand new to this style of brewing, you may want to check out my guide on All Grain Brewing Instructions first. It will give you the bigger picture of how mashing, sparging, boiling, chilling, and fermentation all fit together.
What Is A Mash Out?
A mash out is when you raise the temperature of your mash near the end of the mash rest, usually to around 168°F to 170°F, before you lift the grain basket or begin sparging.
During the mash, warm water activates enzymes in the grain. Those enzymes convert starches from the malted grain into sugars.
Those sugars are what the yeast will later eat during fermentation to create alcohol and CO2.
So when we mash at a temperature like 152°F, we are building a certain wort profile. That wort profile affects the body, fermentability, and final character of the beer.
If you want a deeper explanation of how mash temperature changes your beer, read my guide on Introduction to Mashing Temperatures.
A mash out raises the temperature high enough to slow down or stop most of that enzyme activity.
In simple terms:
You are telling the mash:
“Alright boys, shift is over.”
What Does A Mash Out Do?
A mash out mainly does two things.
First, it helps stop the enzymatic conversion process. You have already spent your mash rest converting starches into sugars. Raising the temperature helps lock in the wort profile you created during the mash.
Second, it makes the wort thinner and easier to drain.
That can help with lautering and sparging, especially when you are using an all-in-one brewing system like a BrewZilla, Mash & Boil, Grainfather, or similar setup.
The hotter wort flows more easily through the grain bed, which can help rinse more sugars from the grain.
That leads directly into sparging, which is the process of rinsing the remaining sugars from the grain. If you want a full breakdown of that step, check out What is Sparging and How to do It.
Is mash out magic?
No.
Is it mandatory?
Also no.
But it can be a useful step, especially if you are trying to follow the full all-grain brewing process and understand what each step does.
Do You Have To Do A Mash Out?
No.
You do not have to do a mash out to make good beer.
Plenty of homebrewers skip it and still make excellent beer.
If you are brewing in a bag, doing small batches, or keeping your brew day simple, you can absolutely make great beer without doing a mash out.
For brewers who want to keep things simple, my How to Brew in a Bag guide is a great place to start. I also have a more detailed BIAB Brewing Instructions guide if you want to dig deeper into that process.
That said, I like doing a mash out when I am filming a full all-grain brew day because it lets beginners see the full process.
It also helps explain how the mash works, what sparging is doing, and why temperature control matters during the brewing process.
If you are new to all-grain brewing, I would say this:
Learn what a mash out is.
Try it a few times.
Then decide if it is worth keeping in your own brew day process.
How To Do A Mash Out
Here is the basic process.
- Mash as normal.
- Near the end of the mash, raise the temperature to around 168°F to 170°F.
- Hold that temperature for about 10 minutes.
- Lift the grain basket or begin lautering.
- Sparge as usual.
That is it.
You do not need to hold the mash out for 20 or 30 minutes.
For most homebrewers, 10 minutes is plenty.
On the BrewZilla, I simply raise the controller temperature, keep recirculating, and let the mash climb up toward mash out temperature.
Once it reaches the target range, I hold it there briefly before lifting the grain basket and sparging.
If you are using a system like the BrewZilla, Grainfather, or Mash & Boil, you may also like my guide on All-In-One Brewing System Instructions.
Mash Out Temperature
The normal mash out temperature range is:
168°F to 170°F
You do not need to hit exactly 170.0°F.
If you land at 168°F, you are fine.
If you land at 169°F, you are fine.
If you briefly hit 171°F, do not panic.
The key is not to go crazy hot, especially when sparging.
You do not want to be blasting the grain bed with boiling water.
A common sparge water range is also around 168°F to 170°F. I go into that in more detail in my guide on Sparge Water Temp.
Keep it controlled and you will be fine.
Mash Out vs Sparging
A mash out and sparging are not the same thing.
A mash out raises the mash temperature before draining or sparging.
Sparging is the process of rinsing sugars from the grain after the mash.
For example, on this brew day:
- I mashed at around 152°F
- Raised the mash to around 168°F to 170°F
- Held it briefly for the mash out
- Lifted the grain basket
- Sparged with hot water
- Then started the boil
The mash out prepares the grain bed and wort.
The sparge rinses the sugars.
Different steps.
Same part of the process.
After sparging, the next major step is getting the wort to a boil. Once the wort reaches a boil, you will usually see the hot break form. If you are not sure what that is, check out What is a Hot Break?.
Should Beginners Do A Mash Out?
If you are brand new to brewing, I would not stress about it.
Focus on the bigger things first:
- cleaning and sanitation
- hitting a reasonable mash temperature
- keeping fermentation temperature under control
- pitching healthy yeast
- not rushing fermentation
- packaging properly
Those things matter more than whether you did a mash out perfectly.
If you are still learning the basics of cleaning and sanitation, read How to Clean & Sanitize Homebrewing Equipment.
If you want to avoid fermentation problems, my guide on How to Ferment Beer is also worth reading.
And if you are wondering how long to let beer ferment before packaging, check out How Long to Ferment Homebrewed Beer?.
But once you start getting comfortable with all-grain brewing, a mash out is worth learning.
It teaches you more about the mash, helps you understand wort flow, and gives you another tool in your brewing toolbox.
BrewZilla Mash Out Tips
If you are using a BrewZilla or another all-in-one system, here are a few tips:
- Keep the pump recirculating gently while heating to mash out.
- Do not open the pump wide if the grain bed is compacted.
- Watch for the wort level rising inside the grain basket.
- Stir gently if needed to even out the temperature.
- Give the system time to climb from mash temperature to mash out temperature.
- Once you hit 168°F to 170°F, hold for about 10 minutes.
- Then lift the basket and sparge.
The BrewZilla may take a little time to climb those last few degrees.
That is normal.
Do not panic and start changing everything.
If you are doing a full brew day and want to follow along with what I am brewing right now, check out The Brewery. That is where I track what is on tap, fermenting, cold crashing, and coming soon at Make Beer Easy.
After Mash Out: Boil, Chill, and Ferment
Once the mash out and sparge are done, it is time to boil the wort, add your hops, chill the wort, and get it into the fermenter.
For this Tropical Thunder Blonde Ale, the goal was a crisp, refreshing summer beer with tropical hop character. The original plan was Mosaic hops, but I ended up brewing it with Citra because Mosaic was not available.
If you want to learn more about the hops involved, read my guides on Mosaic Hops Flavor and Citra Hops Flavor.
After the boil, you need to cool the wort before pitching yeast. I cover that process in How to Cool Wort.
Then it is time for fermentation. If you want to make better beer, fermentation is where a lot of the magic happens. You can learn more in Fermentation Temperatures in Homebrewing Beer and How to Pitch Yeast.
Is A Mash Out Worth It?
Here is my take.
A mash out is not required.
But it is useful to understand.
If you are doing a full all-grain brew day and you are not in a rush, go ahead and do it.
If you are doing a quick brew in a bag batch and want to keep things simple, skipping it is probably not going to ruin your beer.
For this Tropical Thunder Blonde Ale brew day, I wanted to show the full process, so we did the mash out.
Not because it was absolutely required.
Because this was a good chance to explain what it is, what it does, and how to perform one.
That is what Make Beer Easy is all about.
Simple brewing.
Better beer.
Made easy.
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Cheers,
Big Robb