All Grain – My mashing process (batch sparging)

Sometimes it seems that there are nearly as many ways to mash your grains when brewing, as there are brewers.  Although this is an exaggeration, to me it speaks to the fact that most everybody in my local home brew club mashes slightly differently.  Our equipment is different, the ways in which we mash in and mash out are different.  There’s the “to stir the mash or not stir the mash” camps.  Fly sparging vs. batch sparging vs. no-sparge vs. BIAB.  So many ways just to get the sugar out of the grains even!  I batch sparge, so that is what this article will concentrate on.

First off, let me say that I use Beersmith brewing software to write my recipes and determine my mash profiles.  However, it’s probably a good idea first to explain what “mashing” is, since some people that will read this article probably haven’t brewed an all grain beer yet, or for that matter, may have never brewed beer at all and are just looking for information.

Let’s start with definitions of all of the terms I’m going to use.

  • Mash – Crushed malt or grain meal steeped and stirred in hot water to produce wort. (Verb) To release malt sugars by soaking the grains in water. (Noun) The resultant mixture.
  • Wort – The solution of grain sugars strained from the mash tun. At this stage, regarded as “sweet wort”, later as brewed wort, fermenting wort and finally beer.
  • Mash Tun – A tank where grist is soaked in water and heated in order to convert the starch to sugar and extract the sugars and other solubles from the grist.
  • Grist – Brewers’ term for milled grains, or the combination of milled grains to be used in a particular brew. Derives from the verb to grind. Also sometimes applied to hops
  • Liquor – The brewer’s word for water used in the brewing process, as included in the mash or, used to sparge the grains after mashing.
  • Astringent – A drying, puckering taste; tannic; can be derived from boiling the grains, long mashes, over sparging or sparging with hard water.
  • Barley – A cereal grain that is malted for use in the grist that becomes the mash in the brewing of beer.
  • Brew Kettle – The vessel in which wort from the mash is boiled with hops. Also called a copper or boil pot.
  • Enzymes – Catalysts that are found naturally in the grain. When heated in mash, they convert the starches of the malted barley into maltose, a sugar used in solution and fermented to make beer.
  • Grist – Brewers’ term for milled grains, or the combination of milled grains to be used in a particular brew. Derives from the verb to grind. Also sometimes applied to hops.
  • Lauter – To run the wort from the mash tun. From the German word to clarify. A lauter tun is a separate vessel to do this job. It uses a system of sharp rakes to achieve a very intensive extraction of malt sugars.
  • Malting – The process by which barley is steeped in water, germinated ,then kilned to convert insoluble starch to soluble substances and sugar. The foundation ingredient of beer.
  • Sparge – To spray grist with hot water in order to remove soluble sugars (maltose). This takes place at the end of the mash.

Yes, I know.  That’s a lot of terms defined.  However, they each mean something to a brewer.  I’ll explain how I conduct the mash and you’ll have these definitions to look back to.

My mash tun is a 48 quart coleman cooler.  I’ve taken the drain out and put a fermentap weldless spigot in it’s place.  Notice that it uses washers and O-rings for sealing.  The valve is on the outside of the mash tun (cooler) and the rest is on the inside.

fermentap weldless spigot

I attach a food grade hose on the outside to control where it drains to, and on the inside I have a kettle screen.  This screen screws right into the fitting on the left hand side of the fermentap weldless spigot.


This will filter out the grain and let only liquid exit the mash tun.

Mash Tun Bazooka

NAMS and brewery 008

As you can see, I have two mash tuns.  I use the second one at the top when I’m brewing in excess of 10 gallons.  Most of the time, I use the lower mash tun though.

What we’re striving to accomplish is soaking the grain in the correct temperature water, to allow the enzymes to be active.  The enzymes will convert the starches in the grain into sugars that yeast can consume.  We then will rinse the sugars out of the grains to gather our sweet wort into a boil pot.

Now, for my process:

  1. Mashing In
    1. Add strike water to mash tun
    2. Add crushed grain to mash tun
    3. Stir
    4. Close the lid and let it sit for at least one hour
  2. Mashing Out
    1. Add small batch sparge addition
    2. Lauter
    3. Drain 75% of the wort out and bring to a near boil
    4. Add the wort back into the mash tun
    5. Close the lid and let it rest for 15 minutes
    6. Lauter
    7. Slowly drain the wort into the boil pot (this is called the first runnings)
    8. When no more wort will come out of the mash tun, add the second batch of sparge water to the mash tun
    9. Close the lid and let it rest for 15 minutes
    10. Lauter
    11. Slowing drain the wort into the boil pot that contains the first runnings
    12. You’re now ready to boil the wort for at least an hour and add hops.
  • Mashing In
    • I put my hot water (liquor) in my mash tun first and stir until it reaches my strike temperature.  Strike temperature is higher than your mash in temperature.
      • When mashing, we strive to hit an exact temperature.  It is somewhere between 148F and 156F usually.  In this temperature range, the enzymes are active and will convert starches to sugars.  I won’t get into the specifics in this article about how the wort will differ when mashing at the low end or high end.  Let’s just leave it at, it makes a difference in the beers taste, sweetness, mouthfeel, etc.
    • My strike temperature is usually in the mid-160F range.  I put it in hotter than I’ve calculated (I let Beersmith brewing software determine the exact strike temperature for me), and then stir it until it’s right on my strike temperature.
    • As soon as it drops to my strike temperature, I stir in the crushed grains, making sure to break up any dough balls.
      • Dough balls are lumps of crushed grains that are still dry on the inside.  We don’t like dough balls, because the water can’t get to the dry grains and convert starches to sugars.
    • When you’ve finished stirring it all in and have broken up all of the dough balls, it’s time to close the lid and let it sit and do it’s magic.  My mash tun only loses about 1F over a one hour mash cycle.  Usually it’s actually done in about 20 minutes, but most brewers mash for 1 hour.  I sometimes will mash for 90 minutes.  I’ll get into mash times in future articles, but for now, I can say that 95% of my mash times are 1 hour.
    • I’ve never really taken a photo of my mash in progress, but here is a good look at what it looks like.  Yup, it looks like running oatmeal!!  It also smells wonderful.
    • mash in a cooler
  • Mashing Out
    • Now we need to separate the sweet wort from the grain.  Sugars is more soluble at higher temperatures, so we need to raise the temperature of the mash in order to get as much of the sugar into solution as possible.
      • Since I mash in a plastic cooler, I can’t put direct heat on it.  Some of my brewing friends mash in converted kegs and can use propane heaters and directly heat theirs up.  I have to use a different approach.
      • The first thing I do is add a small amount of boiling water (liquor) to the mash.  This small amount raises the temperature slightly and at the same time, it will allow me to have the ability to drain the mash tun twice (the second draining is after another larger addition of hot water called sparging.  Sparging basically means rinsing.
      • Once I’ve stirred in this first smaller addition of hot water, I’ll then start to lauter.  Lauter means to drain, so I slowly drain wort out of the mash tun through the valve into a pitcher.  When the pitcher is just about full, I’ll pour it back into the mash tun and repeat.  I do this until the wort coming out is very clear with little or no grain husks coming out with it.
      • sparge-and-vorlauf
      • Once I’ve lautered, I’ll then let it drain slowly into my boil pot, with the heat on.  I’ll pull about 75% of the expected amount of wort out.  For example, if I’m expecting to gather 8 gallons of wort total (this amount is made up for ease of math, as I actually never gather 8 gallons of wort), I’ll expect this first draining to produce 4 gallons if I drained it completely.  So, I’ll bring about 3 gallons up to a boil or near boil and then I’ll add it back into my mash tun. Yup, I put all that effort into draining out crystal clear, clean wort and then heated it up and put it back into the mash tun!
        • The reason is, that I want the wort that is going to be boiled for an hour to come out of the mash tun at 168F.  This is the hottest that the mash can be, without taking the chance of dissolving grain husks into the wort that can make it through your screen and filter bed.  If you get too hot, you risk at a grainy, astringent flavor to your finished beer.
        • I stir well to get the temperature equalized throughout the mash and close the mash tun lid at this time and let it sit for 15 minutes, so that the sugars have time to fully dissolve.
        • Then I lauter again!  Really well, until it’s running nice and clear.  I’ll usually lauter about 3 one gallon pitchers full.  At this point, it’s finally time to start gathering the sweet wort into your boil pot.  I open the valve just a little bit and let it slowly drain out, until no more will come out.
        • Then I’ll add another batch of sparge water to the mash, to completely rinse any of the sugars left behind from the first draining.  The temperature that I have this water at is usually the same amount above 168F, as the grain temperature has dropped below 168F.  If my grain temperature has dropped to 160F, I’ll add sparge water at 176F, so that it equalizes out at the magic number of 168F.
        • I stir it, close it up for 15 minutes, then lauter slowly and then slowly drain into my boil pot.  I should now have collected 8 gallons of wort, that is ready to boil and add hops to.