There are a couple of different ways to approach your first all-grain brew day. There is a vast amount of information in the homebrew literature about all-grain brewing, and you could try to read most of it first and then proceed. Or, you could jump right in.
Firstly, although there is a lot of interesting technical information out there, you really only need to grasp a few key ideas to get started. As you continue to brew, you can keep learning and fill in any gaps in your education.
Secondly, learning to brew well at home requires some practical experience that you can only get by actually brewing . . . on your equipment, with your water, etc. Getting to know the mechanics of brewing — including the quirks of your setup — is just as important, in terms of beer quality, as knowing many of the more advanced academic ideas. Acquiring knowledge along both these paths at the same time will speed your journey from novice to experienced brewer.
In this article, we'll cover the bare minimum of technical information you need to get started and give a practical guide to successfully brewing your first all-grain beer. I will assume that you are already familiar with brewing with malt extracts.
Required Knowledge (The Minimum)
All-grain brewing differs from extract brewing mainly in the wort production stage. As an extract brewer, you made your wort by dissolving malt extract in water, and likely steeping some specialty grains to add some additional flavors. As an all-grain brewer, you will make your wort from malted grains and water. The basic idea behind all-grain wort production is this:
You soak crushed, malted grains in hot water, then drain away the resulting liquid, which is your wort.
That's it. There are, of course, subtleties that you will learn about later — how finely do you crush the malt, how hot should the grain and water mixture be, how fast do you drain the wort, etc. — but that's the basic idea.
If you have been boiling a dense wort of dissolved malt extract and then diluting it to working strength in your fermenter, you will now be boiling (and cooling) your full wort volume as well. Once your wort is in the fermenter, fermentation and conditioning is handled in the same way as in extract brewing.
A typical all-grain homebrew set up includes three vessels. First, a vessel to heat all the water for your brewing session. As brewing water is sometimes called brewing liquor, the name of this vessel is the hot liquor tank, or HLT. Second, a vessel to hold the grains for both mashing (soaking the crushed grains) and lautering (separating the wort from the spent grains). This is called a mash/lauter tun. (In commercial brewing, these are often separate vessels.) This needs to have a false bottom or some sort of manifold installed to let the wort flow from the vessel while retaining the spent grains. You will also need a large paddle to stir the mash. Lastly, you need a vessel to boil the wort in, called the kettle.
A 5.0-gallon (19 L) brewery can consist of three 10-gallon/40-quart (38-L) vessels. Systems such as this work well for most average to moderately-big brews.
If you don't already have a wort chiller, you will need one. Quickly cooling your wort improves beer quality and a wort chiller works much faster than putting the kettle in a bathtub of cool water.
Finally, you will need a heat source capable of boiling your entire pre-boil volume of wort vigorously. For 5.0-gallon (19-L) batches, you will need to boil at least 6 gallons (23 L), more if you want to make high-gravity beers. For many all-grain homebrewers, the heat source of choice is a propane burner.
There are a lot of options when it comes to choosing all-grain equipment, too many to detail here. Keep in mind that great homebrew has been made on a wide variety of brewing setups.
Calibration and Calculations
Before your frist brew day, you should make a dipstick (or calibrate your sight glasses, if your brewery has those) so that you can measure the volume of liquid in your HLT and kettle. Likewise, calibrate any thermometers that you will be using.
Before starting any brew day, there are two easy calculations you should make — the amount of strike water (water to mix with the crushed grains) and the amount of sparge water (water to rinse the grain bed) you will need. These are explained later.
For your first all-grain brew, you will probably buy crushed malt or get the malt crushed at your homebrew shop. When it's time to brew, take a handful of malt and look at it. With a good crush, you should see almost no whole kernels. Most kernels should be broken into two to four pieces.
If you've bought, or have access to, a grain mill, you will gain experience over time adjusting it to get the best crush for you. For your first crush, however, see if the mill has a "default" setting. This is usually 0.045 inches (0.11 cm). This should give you a good crush and you can start fiddling with adjusting the mill gap when you get more experience.
The goal of the crush is to break the malt kernels open so that the hot strike water can dissolve the starchy endosperm in the malt. You don't need perfectly crushed grain to a have a successful first brew day, so don't worry about this too much. Do, however, examine your crushed grains every time you brew. When the time comes to really start fine-tuning your brewing procedures, this will be valuable to you. Make a note in your brewing notebook about how the crush looked to you.
Water Heating and Mash In
Once your equipment is set up, you will need to start heating your strike water. The amount of water required varies between 0.95 and 2.4 quarts of water per pound of grain (2.0–5.0 L/kg), and a good consistency — or mash thickness — for most beers is 1.25 and 1.375 qts./lb. (2.6-2.9 L/kg). So, to figure out how much water you need, take the weight of your grains and multiply by some number between 1.25 and 1.375 (or 2.6 through 2.9, if you use the metric system). The lower numbers will give you a little thicker mash than the higher numbers, although the specified range is all in the "moderate" range of mash thickness.
If your mash vessel has a false bottom, add the volume under your false bottom to the amount of strike water you need to heat. For example, if there is a gallon (3.8 L) of space under your false bottom, add this extra 1.0 gallon (3.8 L) of water to your strike water. All-grain brews require heating larger volumes of water than most extract brews, so be prepared for this step to take longer than you might think. If you have a metal mash paddle, set it in the HLT while the strike water is heating.
Mixing the crushed grains and hot strike water is called mashing in. The goal is to mix the crushed malt and water so that the grain bed settles in at your target temperature (which will be given in the homebrew recipe) and that this temperature is as uniform as possible throughout the grain bed.
The initial temperature after mash in depends mostly on the temperature of the strike water, the temperature of the crushed malt and the temperature of your mash vessel. There are equations that can help you calculate the temperature of your strike water, but most homebrewers "solve" this problem by using a generic recommendation and refining it with trial and error. One generic recommendation works fairly well if your grain and equipment are in the vicinity of "room temperature," and you use a mash thickness between 1.25 and 1.375 qts./lb. (2.6-2.9 L/kg). This is to heat your strike water to 11 °F (6 °C) above your target mash temperature. This assumes no, or minimal, heat loss when transferring your water to your mash tun.
An improved recommendation — one that works better if your equipment is stored somewhere that is not temperature-controlled — is to adjust the temperature of your strike water once it is in your mash vessel. Heat your strike water to 15–18 °F (8–10 °C) over your target temperature and add the strike water to your mash vessel. Let it sit for two minutes and take the temperature. Adjust the temperature downward, towards 9–10 °F (5–5.5 °C) higher than your target temperature, by removing a couple cups of hot water and replacing it with the same volume of water around room temperature. Aim for 9 °F (5 °C) over if your mash thickness is 1.375 qts/lb. (2.9 L/kg), 10 °F (5.5 °C) over if your mash thickness is 1.25 qts./lb. (2.6 L/kg). Stir the water, take the temperature and repeat until you hit your target. This still assumes that your grain is near room temperature.
Once you've heated the measured amount of strike water and transferred it to the mash vessel, check again to see that it's in the right range (9–10 °F/5–5.5 °C above your target). Then, stir your crushed grains into the strike water. To do this, simply add a pound or so of grain to the water, give a quick stir with your mash paddle until it dissolves and repeat until all the grain is stirred in. Stir the grain for 20–30 seconds, looking to even out any temperature differences and break up any clumps of dry malt sticking together. Then, take the temperature and place the lid on your mash tun to conserve heat. Record the volume of the strike water, its temperature in your mash tun just prior to mashing in and the initial mash temperature.
Now, you let the mash sit (or rest) for awhile. (The recipe should specify the length of this rest; often, it's one hour.) During the mash rest, your goal is to hold the grain bed at a constant, uniform temperature. Odds are, however, you won't be able to do this. At a homebrew scale, the mash will lose heat over the time of the rest. And, the sides of the grain bed will cool off faster than the center. Fortunately, a small change in temperature is not going to hurt the quality of your beer. After your first mash, quickly take the temperature near the side of the mash vessel, and then near the center. Stir the mash to even out any temperature differences and take the temperature again. Record all three temperatures in your brewing notebook.
If your overall mash temperature drops more than 2 °F (1 °C), or the temperature difference within the mash is greater than 4 °F (2 °C), you should insulate your mash tun better next time. You can use towels or blankets for this. If your mash vessel is heatable, you can also add heat directly during the mash. If you do, stir the mash and do not heat too quickly.
During the rest, you have the option of stirring. Stirring ensures a more even mixture of grain and liquid and evens out temperature differences across the grain bed. Unfortunately, opening the mash vessel releases heat to the environment. Likewise, using a "cold" mash paddle absorbs more heat from the mash. As such, most homebrewers simply leave their mash undisturbed during this rest. (If you overshot your mash temperature by a few degrees, stirring a couple times is great way to gradually bring the temperature down.)
Most homebrew recipes specify a one-hour rest for single infusion mashes.
While the mash is resting, begin heating the water you will use to rinse the grain bed (the sparge water). How much sparge water will you need? I would recommend heating an amount equal to the target pre-boil volume of your wort, plus about 20%. This might seem like a huge amount, but this will allow you to collect your full pre-boil kettle volume, keep the grain bed in the mash/lauter vessel submerged throughout the wort collection process and have some extra water that serves as buffer against water in the "dead spaces" (tubing, etc.) loss to evaporation or small amounts of spillage. Running out of sparge water is a pain, whereas leftover hot water can be used for cleaning equipment. So, I try to err on the side of heating too much sparge water. For a 5.0-gallon (19-L) batch, this may mean 7.5 gallons (28 L) or more. If you want to try to leave your grain bed dry at the end of sparging, subtract the volume of strike water from this amount. Also, if you mash out by adding boiling water to the grain bed (see the next section), subtract this volume from the required volume of sparge water.
Your goal should be for the sparge water to be at the correct temperature when the mash is over and the wort has been recirculated. Use the length of time it took to heat the strike water to estimate how long it will take to heat the sparge water.
At the end of the mash, you have the option of performing a mash out. To mash out, you raise the temperature of the grain bed to 170 °F (77 °C). Mashing out makes the wort less viscous, and easier to collect. This can be done either by applying direct heat or by stirring in boiling water. If you heat the mash, be sure to stir as you do. If you add boiling water, you will need a volume that is approximately 40% of the volume of your strike water. Sometimes, the size of your mash tun will preclude you from adding enough water to reach 170 °F (77 °C). This is fine as you can simply rinse with hotter sparge water to compensate for this. Once you arrive at 170 °F (77 °C), or have added all the water your mash/lauter tun will hold, let the grain bed rest for 5 minutes and then you are ready to recirculate. Record the details of your mash out — final temperature and volume of boiling water added (if any).
The aim of recirculation is to draw some wort off from the bottom of the grain bed and return it to the top. Once enough wort has been recirculated in this way, the wort clears up substantially. To recirculate manually, open the spigot to the mash/lauter tun slightly and slowly collect wort in a beer pitcher or similar vessel. Keep a timer running and collect wort at a rate that would fill the pitcher in about 5 minutes. Once full, gently pour the pitcher back on top of the grain bed. Repeat this until the wort looks clearer or 20 minutes have passed. Some homebrew rigs allow you to recirculate using a pump.
Once recirculation is finished, it's time to start collecting wort. To do this, slowly open the valve on your mash/lauter tun and let the wort start trickling in to the kettle. If your lauter tun is not positioned above the kettle, you can let the wort flow into a pitcher and then pour wort into the kettle. Collect the wort at a rate such that takes about 60–90 minutes to collect the entire volume. To do this, keep the dip stick in the kettle and check on it every few minutes. Write down the time you start collecting wort and the time you cross the 1-gallon mark, 2-gallon mark, 3-gallon mark, etc.
You might think that simply leaving the ball valve on the spigot in the same position would keep the flow rate steady, but a lot changes as you are collecting wort. It gets progressively thinner, it may change in temperature and the amount of pressure from the water above the grain bed changes with the level. The grain bed itself can get compressed, slowing the flow of wort, So, especially on your first few brews, take a look every couple minutes at the amount of wort in the kettle and adjust the valve, if needed, to keep the wort flowing at the proper rate. Be especially careful to check your kettle after opening the valve to increase the flow of wort; if it starts to flow too quickly, you can drain the mash tun in a matter of minutes. Don't worry if wort collection doesn't go as planned on your first brew day. If you collect the wort too quickly, the only harm would likely be an original gravity slightly lower than you would have achieved otherwise.
When you first start collecting wort, there is a layer of water above the grain bed. Once the liquid level falls to almost the top of the grain bed, you should start applying sparge water. Your goal when sparging is to rinse "the good stuff" out of the grain bed, while not rinsing so extensively that you start extracting anything "bad."
The basic idea with continuous sparging is to apply water to the top of the grain bed at the same rate as it drains from the lauter tun. In theory, that should be simple. In practice it can be hard to match the flow rates. A simple way around this problem is to focus on getting the flow rate from the mash/tun to the kettle correct, then apply sparge water at a faster rate in intermittent bursts. On my old setup, I used to pour a couple pitchers of water on top of the grain bed, then, about 10 minutes later — right before the grain bed would be exposed — I'd add another two pitchers. During this time, wort would be flowing from the lauter tun to the kettle at a steady rate. Now, I do essentially the same thing by turning on and off my pump. Adding your sparge water in "pulses," rather than trying to get the flow rate to match the outflow from your mash/lauter tun is simple and lets you focus how fast your kettle is filling.
You should heat your sparge water to the point that, as you sparge, the temperature of the grain bed approaches 170 °F (77 °C). If you mashed out to 170 °F (77 °C), and your lauter tun was well insulated, your sparge water should be 170 °F (77 °C) at the point that it is added. In this case, it may have to be hotter than 170 °F (77 °C) in the HLT if it travels through tubing (where it will lose temperature) on the way to your lauter tun. If your grain bed is cooler than this, then sparging with water at 190 °F (88 °C) or higher is appropriate until the grain bed reaches 170 °F (77 °C). Write down the details of your sparging in your brewing notebook.
When to Stop
There are a few ways to determine when to stop collecting your wort. For average-strength beers, the easiest way is just to quit collecting when you've got the full pre-boil wort volume in your kettle. With a propane burner, on homebrew-sized batches you can expect to boil off about a gallon an hour with a full rolling boil. So, for a 5-gallon (19 L) batch, you could collect 6 gallons for a one-hour boil or 6.5 gallons for a 90-minute boil.
A better way to know when to stop collecting wort is to monitor when you've gotten everything you reasonably can from the grain bed. The easiest way to do this is to take the specific gravity of your late runnings (the stream of wort you are collecting from the grain bed) and wait until they fall to about 1.008-1.010. If you do this, you may end up with more or less wort than your planned pre-boil wort volume. If you are low, as happens on many low-gravity brews, just add water. If you have collected more wort than you planned, you can extend the length of your boil. When you are done collecting wort, write down the volume of wort in your kettle, the time you quit collecting and the original gravity of the wort. Also record if you needed to add any water to reach your target pre-boil volume.
Boiling and Beyond
For extract brewers who do full wort boils, the rest of your brew day is identical to what you are used to. If not, just expect that heating and cooling a larger volume of wort will take longer.
Now you've got your first all-grain brew day under your belt. You also have a record of all the relevant volumes, temperatures and times of your first all-grain batch. Before you grab a celebratory beer, write down any other observations that you feel may help you with future brews. Later, before your second brew, review your notes and determine what aspects of your brew day you want to improve upon. Knowledge comes quickly at first, so be sure to write absolutely everything down for your first several beers.