Cheap and Easy Batch Sparging
Some homebrewers aspire to go pro. Some like to use professional style systems and techniques for their homebrewing endeavors. Some get their kicks from designing fancy automated systems for their brewing. Not me; I take a simple, hands-on approach with my brewing. For me, it’s cheap and easy batch sparge brewing. In this article, I’ll show you the technique and explain how to build an inexpensive mash/lauter tun for batch sparging.
What is Sparging and How Do You Do It?
Sparging is rinsing the grain bed with water to extract as much of the sugar as possible. For our purposes, we’ll specify that sparging begins only after the runoff of the sweet wort from the mashtun has begun. There are several different forms of sparging.
Fly Sparging
Most brewers practice continuous sparging. This is also called on the fly or fly sparging. In this method, after recirculation the wort runoff is begun and water is added to the lauter tun at the same rate as wort is runoff. With fly sparging, it’s important to collect wort slowly to extract the maximum amount of sugar. For fly-sparging homebrewers, wort collection typically takes 60–90 minutes. Lauter design is also highly important in fly sparging. Your lautering system must allow no channeling or the sparge liquor will “drill” straight down through the grain bed in only one or two locations and leave the rest of the mash unrinsed.
Because the runoff may take an hour or more, many brewers do a mashout — an addition of near-boiling water to raise the temperature of the grain bed to around 168 °F (76 °C). The mashout reduces wort viscosity to improve run-off, but also denatures the enzymes and prevents further conversion from taking place while fly sparging is proceeding.
No Sparge Brewing
A no sparge brew has the entire volume of “sparge” water added to the mash and stirred in before any runoff has taken place. Since the additional water has been added to the mash before the runoff has begun, we can more properly think of it as a mash infusion, rather than a sparge addition — hence the name “no-sparge.” Wort collection consists of just draining the mash tun and usually takes less than 10 minutes.
Batch Sparging
Batch sparging is similar to partigyle brewing. In partigyle brewing, progressively weaker worts are run off from the lauter tun and each wort is made into a different beer.
With batch sparging, the runoffs (usually the first two) are combined into a single batch. After conversion, the sweet wort is recirculated as normal and the mashtun is completely drained as quickly as possible. This usually takes about 3–5 minutes. Next, an addition of sparge water is added. This water is stirred into the mash, allowed to rest for a few minutes, thoroughly stirred again and — after recirculation — is once more drained as quickly as the system will allow. The second batch usually takes about 3–5 minutes to collect. There are several advantages to batch sparging.
A lautering setup that is inefficient when fly sparging will be more efficient when batch sparging because there are no “dead” spots in the grain bed. A mashout is seldom necessary (although it may be desirable) when batch sparging because the wort will be in the kettle more quickly and enzymes denatured by boiling. Batch sparging takes more time than no-sparge brewing, but less time than fly sparging.
Formula
It is relatively simple to figure out how much water to add for each batch. Most of the following is drawn from and builds on the work of Ken Schwartz and Bob Regent. The main concept to understand is that, for the best efficiency, the runoff volumes from your mash and batch sparge should be equal. In order to do that, it’s sometimes necessary to infuse your mash with extra water before the first runoff. To figure out the amount for your system, both of the following relationships must be satisfied:
R1 + I + S(1) + S(2) + . . . + S(X) = V
AND
R1 + I = 0.5V
In the equations, R1 is the initial runoff volume. This equals the mash water volume minus the water absorbed by grain. (In my brewery, with my mill, this is 0.1 gallons of water per pound of grain. Your value may be different.) “S” is the batch sparge water volume; “V” is total boil volume (amount needed in kettle for boil) and “I” is the volume of water infusions for a step mash.
Assume a recipe with 10 lb. (4.5 kg) of grain, and that you need to collect 7 gallons (26 L) of pre-boil wort. A mash ratio of 1.25 qt./lb. (0.68 L/kg) would require 12.5 qt. or 3.125 gallons (12 L) of strike water. Based on an absorption of 0.1 gallons/lb., the mash would absorb 1 gallon (3.8 L) of water so we’d get 2.125 gallons (8.0 L) of water from the mash. Since we want to collect 3.5 gallons (13 L, or 50% of the boil volume), after the mash is complete we’d add 1.375 gallons/5.5 qt. (5.2 L) of water to mash tun before the first runoff. Stir the additional water in, let it sit for a few minutes, then vorlauf (recirculate the wort through the grain bed) until clear and start your runoff. After the runoff, we add 3.5 gallons (13 L) of batch sparge water. Stir it in, rest 10–15 minutes, stir again, then vorlauf and runoff as before. These two runoffs will give our pre-boil volume of 7 gallons (26 L) of sweet wort. Now, let’s take a look at how to build the equipment and do a brew session!
Building the Mashtun
For the mashtun, you’ll need a cooler. I prefer the rectangular ones. You’ll also need a rubber bung for a minikeg, some 1/2 inch OD x 3/8 inch ID food grade vinyl tubing — long enough to reach from whatever you set your cooler on to the bottom of your kettle plus 6 inches. Finally, you’ll need an inline nylon valve, and a length of water supply line (with a stainless steel braid for a jacket), and 3 hose clamps. The length of the water supply line doesn’t really matter. I use one that’s long enough to run the length of the cooler, but my experiments have shown that shorter ones seem to work as well.
Step by Step
1. Remove the spigot from the cooler. Usually, there’s a nut on the inside of the cooler holding the spigot on. Unscrew that and the spigot should pop right out.
2. Remove the plastic insert from the hole in the minikeg bung and insert the bung into the spigot hole from the inside of the cooler. The beveled edge of the bung goes in first and the flange of the bung should end up flush with the cooler wall.
3. Cut off a 6-inch piece of the vinyl tubing and, from the inside of the cooler, insert it into the hole in the minikeg bung. Let a couple inches of tubing protrude from each side of the cooler.
4. Cut the threaded fittings off the water supply line. Pull the tubing out from the braid, leaving you with a hollow length of hose braid. Flatten the last inch or so of one end of the braid. Fold it over on itself 3 times to seal the end. Squeeze the fold with a pair of pliers to crimp it closed.
5. Slip a hose clamp over the end of the braid, and slip the braid over the end of the vinyl tubing inside the cooler. Tighten the clamp until snug, but don’t squeeze the tubing shut!
6. Insert one end of the valve into the tubing on the outside of the cooler and secure it with a hose clamp. Slip another hose clamp over the end of the long piece of tubing, connect the tubing to the output side of the valve, and secure with the hose clamp.
That’s it! You’ve built your cheap and easy mash/lauter tun! Now, let’s brew some beer!
Your First Batch Sparge Beer
Let’s walk through an actual brew session. This is from a 8-gallon (30 L) batch of altbier I brewed recently. Remember that the method can be used with any brewing system or equipment. The equipment you’ll need is: your converted cooler mash tun, a pot to heat water in (5 gallons/19 L minimum recommended), a 1–2 qt. heatproof pitcher (preferably unbreakable), your regular brewing equipment — thermometer, boil kettle and whatever else you normally use. The things that you need to know to figure your water volumes are: Total grain weight, in this case, 19.3 lb.; strike water volume, in this case, 1.24 qt./lb. or 6 gallons; absorption of water by grain, for me 10 lbs. (4.5 kg) of grain absorbs 1 gallon (4 L) of water. If you don’t know your absorption volume, measure your first runoff volume the first few brews. By knowing how much water you put in and how much wort you got out, you can easily figure your absorption. Finally, we need to know our pre-boil volume — how much sweet wort you need to start with. For this batch, we want 10 gallons (38 L), which on my system will yield 8 gallons (30 L) of post-boil wort. OK, we’re ready to brew!
1. Mash in with 6 gallons (23 L) of water for 1.25 qt./lb. I use the pitcher to pour water from the 7 gallon (26 L) kettle until the kettle is light enough to lift and pour the rest of the water in. I predict that the grain will absorb 1.9 gallons (7.2 L), so I should get just about 4 gallons (15 L) out of the mash.
2. Since I’d like to get 5 gallons (19 L) out of this runoff, I infuse with 1 gallon (3.8 L) of water at the end of the mash, before the first runoff. I add boiling water to get as close to the 168 °F (76 °C) mashout temperature as I can and stir it in.
3. After 10 more minutes, I begin to recirculate the mash by draining into the pitcher. I only open the valve partially at first, then as the runoff clears I open it up fully. With the hose braid, I usually only have to drain about a quart or so until it’s clear. Keep draining and recirculating until the runnings are clear and free from pieces of grain.
4. Once the runnings clear, direct the runoff to your kettle, and slowly pour the contents of the pitcher back over the top of your mash.
5. Completely drain the mash tun as fast as your system will allow.
6. As the first runoff progresses, start heating your batch sparge water. In this case, we’re going to heat 5 gallons (19 L) to about 185 °F (85 °C) to try to get to a grain bed temperature in the 165–168 °F (74–76 °C) range.
7. When the first runoff is done, add your second addition of sparge water. Stir the grain thoroughly, close the cooler, and let it rest for a few minutes.
8. After the rest, open the cooler and thoroughly stir the grain once again. Yep, you read that right! We want to get all the sugar into solution.
9. Go through the recirculation and draining process again, once more draining the cooler as fast as your system will allow.
10. Continue the brewing process as you usually do.
Congratulations . . . you’ve batch sparged! Like anything else in brewing, it may take a couple tries before you get everything figured out completely. But with batch sparging, you can brew all grain beers with a minimal investment in equipment and a pride in the hands-on fun of homebrewing.
