Master The Mash - All Grain Brewing

If you want the ultimate control of your ingredients and to brew something “from scratch,” then all-grain brewing is the way to go. By moving to all-grain brewing you will be mashing the crushed grains at various temperatures to obtain the sugars for your wort. This more advanced brewing process requires a few more pieces of equipment, and will increase your brewing time, but the results can be fantastic. This process is explained in Chapter 19: Your First All-Grain Batch of John Palmer's book, How To Brew.

The following excerpt is Chapter 19. Your First All-Grain Batch, from John Palmer’s book, How To Brew!

One of the comments you will most often hear from first-time all-grainers is, “I didn’t realize it would be so easy!” Making beer from scratch is really very easy; it just takes some preparation and some understanding of what needs to be done.

So far, you have seen the various steps and delved into the details in a few areas, but the best way to learn is by doing. Ideally, you have done several extract batches and a couple of extract-and specialty grain batches by now. You should know to have your ingredients and brewing water ready, with everything clean and sanitized. Unless you have purchased a grain mill, have the grain crushed for you at the brewshop. Crushed grain will stay fresh for about two weeks if kept cool and dry.

Additional Equipment

Mash/lauter tun. The easiest way to brew all-grain beer is to use a picnic cooler mash/lauter tun. I described how they can aid mashing and lautering in Chapters 16 and 17, and instructions for building one are given in Appendix E. A 36- to 48-quart rectangular cooler or 10-gallon round beverage cooler is probably the best choice.

Sparge water pot. You will need a large pot to heat your mash water and your sparge water.  You can use your old 5-gallon brewpot for this, or you can purchase a larger 8-gallon pot. You will probably use 3 to 4 gallons of water for a typical mash, and you will need another 3 to 4 gallons of water for the typical sparge, so be forewarned.

Wort boiling pot. You will need to get a new brewpot, because you are going to be boiling the whole batch. You need a pot that can comfortably hold 6 gallons without boiling over. An 8 gallon stainless steel stock pot from your local Home Brew store or restaurant supply store, or a more economical alternative is an 8-gallon enamelware pot, although these are more prone to chipping and scorching. 

 You will want to purchase a hydrometer, if you don’t have one already. A hydrometer allows you to monitor the extraction process.

Suggested Recipe

For this beer, we will make a brown ale, using four malts and a single-temperature infusion mash. I will take you through the entire grain brewing procedure and then go back and discuss some options for various steps.

Oak Butt Brown Ale


Malts Gravity Points
7 lbs. (3.2kg) pale ale malt 30
2 lbs. (0.9kg) Victory malt 8
0.5 lb. (227g) crystal 60L malt 2
0.25 lb. (113g) chocolate malt 1
BG for 6.5 gallons 1.041
OG for 5.5* gallons 1.049


Hops Boil Time IBUs
0.5 oz. (14g) Nugget (12%) 60 21
0.5 oz. (14g) Willamette (5%) 15 4
Total IBUs   25



Fermentation Schedule
WLP013 London Ale Primary ferment at 68° F (20° C) for 2 weeks


Partial mash:

  • 2 lbs. (0.9kg) pale ale malt
  • 2 lbs. (0.9kg) Victory malt
  • 0.5 lb. (227g) crystal 60L malt
  • 0.25 lb. (113g) chocolate malt

Add to boil:

  • 4 lbs. (1.8kg) pale LME

Mash Schedule—Single-Temperature Infusion


Rest Type Temperature Duration
Conversion 152° F (67° C) 60 min.


Mash Schedule

  • Single infusion of 160° F (71° C) strike water at a ratio of 2 quarts/pound grain (= 19.5 quarts or 18.5 liters).
  • Target mash temperature of 152° F. (67° C) Mash time of 1 hour. No mash-out.
  • Drain wort to collect 3 to 3.5 gallons. Batch sparge with 3.5 gallons to collect 6.5 gallons total.
  • Target gravity of 1.041 for 6.5 gallons (or 1.049 for 5.5 gallons after boiling).
  • Adjust the amount of chocolate malt (0.25 to 0.5 pounds) depending on how dark you want it.
  • The extra half-gallon provides for wort soaked up by the hops and break material in the boiler, giving you 5 gallons of clean(er) wort in the fermenter.

Partial Mash Option

Not everyone can jump right into full mashing. An option is to use a small mash to provide wort complexity and freshness, plus a can of extract to provide the bulk of the fermentables. This option is particularly attractive for brewers living in small apartments without room in the kitchen for a lot of equipment. Using a partial mash was how I first started using grain, and I was extremely pleased with the results.

A partial mash is carried out just like a fullscale mash, but the volume of wort collected is only the 3 to 4 gallons that you would normally boil when brewing with extract. The advantage over an extract and steeped specialty grain procedure is that you’re actually mashing, which means you’re not limited to just crystal and roasted grains. Typically, a can of extract is substituted for some of the base malt, and the specialty grains in the recipe are retained.

You can mash in either a pot on the stove or buy a smaller cooler (3 to 4 gallons) and build a small manifold. You probably have a small beverage cooler already that would work well with a drop-in manifold [see appendix E in How To Brew]. One advantage to using a manifold versus pouring the mash into a strainer is that you avoid aerating the wort while it is hot. As was discussed in previous chapters, oxidation of hot wort at any time will lead to flavor stability problems in the beer later.

Starting the Mash

  1. Heat brewing water. Heat up enough water to conduct the mash. At a water-to-grain ratio of 2 quarts/pound (4 liters/kilogram), the amount would be 19.5 quarts (18.5 liters), or about 5 gallons. Always make more, you will often need it. Heat up 5 gallons (19 liters) in the larger of your two brewing pots. At a mash ratio of 2:1, the initial infusion temperature should be 160° F (71° C) to create a mash temperature of 152° F (67° C). Depending on the amount of heat lost to the tun, the strike water could be as hot as 165° F (74° C), but that would (theoretically) create a mash temperature of 156° F (69° C). That would make the wort more dextrinous than we intended, but it would still be a fermentable wort. (See Chapter 16 for the infusion calculations.)
  2. Preheat the tun. Preheat the cooler with some boiling water, about a gallon. Swirl it around to heat up the cooler, and then pour it back to your sparge water pot. Preheating will prevent initial heat loss from the mash to the tun, which can throw off your infusion calculations.
  3. Mash-in. You want to add the water to the grain, not the other way around. Use a saucepan or a plastic pitcher to pour in a gallon of your strike water at a time and stir between infusions. Don’t try to pour 4 gallons of hot water into the mash tun all at once. You don’t want to thermally shock the enzymes. Stir it thoroughly to make sure all the grain is fully wetted, but don’t aerate it. Hot-side aeration is promoted by a malt enzyme called lipoxygenase at this stage, but it is denatured as the temperature reaches 140° F (60° C). Oxidation of wort compounds will not be affected by the subsequent boil and will cause off-flavors later.
  4. Check the temperature. Check the temperature of the mash to see if it has stabilized at the target temperature of 152° F (67° C) or at least in the range of 150 to 155° F (65 to 68° C). If the temperature is too low, e.g., 145° F (63° C), add some more hot water. If it is too high, e.g., 160° F (71° C), then add cold water to bring it down. 156° F (69° C) is the highest we would want for this recipe. It will yield a sweet, medium-bodied wort with good attenuation. See Figure 106.
  5. Adjust the temperature. OK, the mash temperature came out a little low (148° F), so I added 1.5 quarts of boiling water to bring it up to 152° F.

Conducting the Mash

  1. Monitor. Stir the mash every 15 to 20 minutes to prevent cold spots and help ensure a uniform conversion. Monitor the temperature each time you stir. If the temperature drops by less than 5 degrees over the hour, nothing further needs to be done. Cover the mash tun with the cooler lid between stirrings, and let it sit for a total of 1 hour. If you notice that the temperature drops below 145° F (62° C) within a half-hour, you can add more water to bring the temperature back up.
  2. Heat the sparge water. Meanwhile, heat up your sparge water in the smaller of your two brewpots. You will need about 3.5 gallons (13 liters) for the batch sparge volume. The water temperature should be less than boiling, preferably 165 to 175° F (73 to 80° C). If the sparge water is too hot, the probability of tannin extraction from the grain husks increases substantially.

Conducting the Lauter

Ok, the hour has gone by, and the mash should look a little bit different. It should be less viscous and smell great.

  1. Recirculate. Open the valve slowly, and drain about 2 quarts/liters of the first runnings into a pitcher. The wort will be cloudy with bits of grain. Gently pour the wort back into the grain bed, recirculating the wort. Repeat this procedure until the wort exiting the tun is pretty clear (like unfiltered apple cider). It will be dark amber colored, hazy, but not cloudy. It should only take a couple of quarts.
  2. Lauter. Once the wort has cleared, drain the wort carefully into your boiling pot. If you open the valve wide at first, you will suck a lot of fine particles into your manifold or screen and can clog it. Only open it part way, until it starts running clear. Fill the pot slowly at first, and allow the level to cover the outlet tube. Be sure to have a long-enough tube, so that the wort enters below the surface and does not splash. The splashing of hot wort before the boil can cause long-term oxidation damage to the flavor of the beer. Once the outlet is submerged, you can open the valve more fully and drain the wort more quickly. But if you drain it too quickly, you can compact the grain bed and get a stuck sparge.
  3. Add the sparge. Close the valve, and add your sparge water to the mash tun with the pitcher, until there is a small enough volume to just dump in the rest. Stir the grist thoroughly to dissolve as much remaining sugar into the wort as possible. There is a chance of dissolving unconverted starch into the wort at this stage, so it doesn’t hurt to let the mash sit for 15 minutes to allow residual alpha-amylase to convert it to sugars. Recirculate and drain to your brewpot.
  4. Stuck sparge? If the wort stops flowing, even with water above the grain bed, then you have a stuck sparge. There are two ways to fix it: (a) Blow back into the outlet hose to clear any obstruction of the manifold; and/or (b) Close the valve and add more hot water, stirring to resuspend the mash. You will need to recirculate again. Stuck sparges are an annoyance but usually not a major problem.
  5. Calculate your efficiency. Measure the gravity in the boiling pot (stir it first), and multiply the points by the number of gallons you collected. Then divide by the number of pounds of grain you used. The result should be somewhere around 28. 27 is OK, 29 is better, and above 30 is great. If it is 25 or below, you are not getting good conversion in the mash, which could be caused by having too coarse a grist, the wrong temperature, not enough time, or a pH factor, etc. (In liters°/kilogram, these numbers are: 234 nominal, with a range of 225 to 250 liters°/kilogram.)

Ok, throw the spent grain on the compost pile, and you are done! You have produced your first all-grain wort! All-grain brewing produces more break material than extract brewing, so you will probably want to add Irish moss during the last 15 minutes of the boil to help with coagulation of the hot break and clarity. Rehydrate it in warm water before use for best results. Don’t overboil, or its effects will be lost back into the wort.

Well, that was pretty easy, wasn’t it? Not too much spillage, I hope. A little practice, and you will be able to do it in your sleep.