Introduction to Mashing Temperature

Learning how to mash correctly, including starting at the correct mash in temperature to ensure that once the grains are added the target mash temperature is reached can be a challenge when you are just starting out to say the least.

But it does not have to be, in fact, once you understand the basic process mashing is a fun and simple part of the beer-making process. In this article, we are going to explain what happens during mashing, how to make sure you hit your mash temperature, as well as what to do if you miss it.

What is Mashing

Alcohol is produced when yeast consumes sugars. When it comes to making beer the sugar comes from the grains. However, when making all-grain beer vs from malt extract, you must extract the sugar from them, this is where mashing comes into play and is so important to the beer-making process.

Mashing simply involves adding crushed grains to hot water and letting them soak for at least one hour. As the crushed grains are soaking, malt enzymes are activated which in turn begin converting the starches with the grains into the fermentable sugars the yeast needs to do its job.

The amount of mash water you use is important and you should strive for a ratio of 1.25 – 1.50 quarts of water per pound of grain, the mash should have a porridge-like consistency.

When the mash has completed you will remove the grains or drain the liquid off and move onto the boiling stage of the process.

Mashing Temperature

The required mashing temperature for beer is between 145 – 158℉ (63 – 70℃), and most beers will have a mash temperature of 150 – 154℉ (65 – 67℃). These temperature ranges are required in order to activate the enzymes that convert the starches from the grains into the simple sugars required to ferment.

The temperature range is important as it determines many of the characteristics of the beer, such as flavor, mouthfeel, and alcohol content.

Mashing at the higher end of the scale typically between 155 – 158℉ (68 – 70℃) it will result in the production of more unfermentable sugars or what is referred to as longer sugars which are harder for the yeast to ferment. Which depending on the style of beer is a good thing and what you are striving for as it produces fuller-bodied beers. Stouts and many pale ales will be mashed at higher temperatures.

Don’t panic if you go over that range slightly as long temperatures don’t go over 168℉ (75℃) you will be ok; simply strive to bring the mash temperature back down to your target as quickly as possible and we will explain further in this article how to do that.

Even if you do go over 168℉ (75℃) for a short period of time (under 10 mins) the beer will still be ok as enzymes will not get destroyed that fast which is why when you are doing a mash out you need to hold that temperature for at least 10 minutes. As long as you bring the temperature back down to the target mash temperature asap all will be well.

Alternatively, when you have a lower mash temperature typically between 140 – 150℉ (60 – 65℃) it will result in the production of shorter sugars which the yeast has no problem fermenting and consumes most of them and does so very quickly. This results in a beer that is drier and has a thinner mouthfeel. If mash temperatures get too low then not much of any starch conversion will occur which will result in a very watery beer with very little alcohol or mouthfeel.

The sweet spot for most beers and where we recommend most brewers aim for is a mash temperature between 150 – 154℉ (65 – 67℃), this will result in the excellent conversion of starches to sugars that the yeast will easily be able to ferment, and will also provide for a medium mouthfeel and body.

Keep in mind that this site is called Make Beer Easy for a reason, we keep things simple, and trust us if you do your beer will turn out good to great, don’t overcomplicate this. Many new brewers get very concerned about hitting their mash temperature, don’t stress over this, as long as you are within 5 degrees of your target your beer will turn out just fine. Keep in mind that back in years gone by there were no thermometers and yet somehow they made what is reported as good beer.

Mash in Temperature

Your mash-in temperature is also referred to as strike water temperature which is the temperature of the water you are going to mash with before adding the grains. 

A man mashing grains into his kettle next to the words introduction to mashing temperature.
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Novice brewers make the mistake of heating their mash water up to their target mash temperature and then adding the grains; when they do this they very quickly realize that a drop in temperature occurs and now their mash temperature is much too low.

As such your strike water needs to be warmer than your target mash temperature, depending on your system it may need to be 8 – 12℉ warmer. There are many complicated formulas you can implement to determine your mash in temperature, however, we prefer to use online calculators and there are lots of free ones on the internet.

This calculator by brewers friend will calculate how much strike water you need and what temperature it needs to be.

How to Fix Your Mash Temperature

Missing your mash temperature will happen from time to time, whether you made an error in your calculations or your mash tun was cold, etc. Although it will probably affect the characteristics of your beer a slight bit, the good news is that in most cases it will not make that much of a difference at all. The key is to move quickly to get the temperature inline as fast as possible.

How to Fix a Low Mash Temperature

If your mash temperature is too low the following are a few ways to get it back up to the right temperature…

Add Some Warm Water

The most common method if you don’t have a heating element is to simply add some warm – hot water slowly to the mash while stirring. Boil some water in a pot and pour a little bit at a time into the mash tun, stirring as you do, take temperature readings until you have hit your target temperature.

The key here is to remember that since you are adding more water you are going to need to make adjustments in regards to how much water you are going to sparge with in order to not go over your target pre-boil level. Meaning you are going to have sparge with less water than planned.

Turn On The Element

If your mash tun also serves as your boil kettle or HLT and has a heating element then simply turn on the heat. This is a great option as you are not adding any additional water and will be able to sparge with the volume of water you planned.

The key here is to make sure you don’t scorch the wort, a few ways to prevent this is to first go easy on how high you turn your element on and don’t make it too hot. Also, be sure to stir while you are heating the mash, this will help not only prevent scorching but to evenly distribute the heat from the bottom of the kettle to the wort at the top.

And lastly, you can also vorlauf which will accomplish the same thing i.e. prevent scorching and evenly distribute the heat. Vorlauf is performed by simply taking a pitcher or a pot and draining some wort through the spigot on the bottom of your mash tun and then slowly pouring it evenly across the top of your mash.

Of course, if you are using a HERMS or RIMS system simply recirculate the wort using your pump.

Use a Hand Held Element

You can now order handheld water-heating elements also referred to as heat sticks whereas before you had to make your own and it was a rather risky venture in our opinion to do so. They are capable of heating up the wort very quickly so it is important to be stirring constantly while using it and keep a close eye on your wort temperature and also be very careful not to burn yourself with it.

Decoction Mash

Lastly, you could implement the old-school traditional method of how they used to mash their beer before thermometers were invented. A decoction mash is where you remove about ⅓ of the mash and pour it into a separate pot and bring it to a boil, again making sure to stir so as not to scorch it, when the mash reaches a boil pour it back into the original mash tun, stir it and check your temperature. Continue to do additional decoction mashes until you have reached your target temperature. A decoction mash can also add some additional body and flavor to your beer.

How to Fix a High Mash Temperature

Fixing the temperature on a mash that is too high is usually a much simpler process and can be done rather quickly without any extra equipment needed.

Use an Immersion Wort Chiller

If you use an immersion wort chiller to cool your wort at the end of the boil it will also work perfectly to bring your mash temperature in line. Keep in mind it will cool your wort quickly so keep a careful eye on the temperature.

Add Ice Packs

Frozen containers such as ice packs or even frozen water bottles are handy to keep around when you are brewing beer. They work great for lowering the mash temperature, simply drop some in and stir the mash taking temperature readings as you go. The great thing about ice packs is they do not add any water volume to your mash so no volume adjustments will need to be made.

Add Some Ice Cubes

As easy as it sounds, simply pour some ice cubes into your mash tun. They will lower the temperature faster than water, and you won’t need a lot of them so be sure to be stirring and taking temperature readings. The other thing with using ice cubes is that it is going to add water volume to your mash, but unlike water, it is difficult to keep track of how much volume you are adding, so you will need to be careful when sparging to ensure you are not going past your pre-boil target volume.

Add Some Cold Water

Simply add some cold water slowly to the mash tun, stirring and taking temperature readings as you do. Keep in mind that just like adding hot water to raise the temperature you need to keep track of how much water you are adding so you can make the proper adjustment on the volume of sparge water you use in order to meet your target pre-boil level.

Frequently Asked Questions

What temperature is too high for mash?

You would never want to have a target mash temperature over 158℉ (70℃). However, it is not until you get up into the 168 – 170℉ (75 – 77℃) that you run the risk of killing the enzymes and stopping the conversion process from happening. However don’t panic if you accidentally reach those temperatures, the enzymes are not destroyed immediately and as long as you get the temperature back down to the proper range within 10 minutes you will be fine.

How do you measure mash temperature?

Temperatures vary at different locations in the mash tun, it can be hotter towards the bottom and lower towards the top so it can be a challenge to get an accurate reading. Some people will measure at the bottom, middle, and top and then take the average. Other people will give the mash a good stir so that the heat is evenly distributed throughout and take a measurement in the middle.

How long is too long to mash?

Wort will start to sour in the mash tun if it is left for over 24 hours. At our brewpub, we mashed overnight many times as it shortened the brew day the next day. However, when it comes to the conversion of enzymes there is not much point in mashing much longer than 60 minutes as that is when the majority of it happens and after 120 minutes it has completely finished.

P.S. Be sure to grab your gift of Big Robbs’s 5 favorite recipes from his brewpub. Details are on the side of the blog or at the bottom if you are on your phone. Cheers!

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