Types of Sparging
Sparging could loosely be defined as the act of washing the converted sugars out of the grain matter in the grist after your mash is complete. There are many ways someone could go about sparging, however, for the sake of categorization, they can be broken down into three categories - Fly Sparge, No Sparge, and Batch Sparge.
The standard way brewers have mashed for centuries is known as Fly Sparging. Fly sparging involves slowly adding water above the grain bed while draining an equal amount from the bottom simultaneously. This method is efficient, time tested, and effective.
The No Sparge method is simple, straight forward, and rarely used. This involves simply draining the mash water completely, adding your sparge water, and draining again. There's always something to be said for simplicity, however, efficiency suffers greatly.
That brings us around to the star of this article ... The Batch Sparge.
The Basic Batch Sparging Technique
Using the Batch Sparging method, your goal is to collect two equal volumes of the total wort to be boiled in two mash tun runnings. The first running will be the wort collected from your initial mash. The second will be the wort collected from your sparge.
To achieve this, you will first need to know how much water each step requires. There are lots of formulas that you may have seen that help you figure this out. The water calculation process is a whole article to itself. For now, let me just recommend that you use one of the spreadsheets available on the internet or, better yet, use an inexpensive program like BeerSmith that will help you figure out these exact volumes.
So let's say you have used your BeerSmith program and it says that you need to mash with 4.5 gallons, and sparge with 3.6 gallons in order to achieve two batches of 3.5 gallon wort. Here is how you would procede:
Step 1 - Add your 4.5 gallons and grain together in your mash tun at the correct strike temperature (also calculated in your handy BeerSmith program.) Let it sit for an hour or so.
Step 2 - Open the valve on your mash tun and drain 1 - 2 quarts into a pitcher. Take this and slowly pour it back into the mash tun so as to not disturb the grain bed. Repeat three or four times or until there is no particulate matter coming out and the wort is as clear as it is going to get. This is called the vorlauf and is used to help set the grain bed to be used as a filter when you are draining.
Step 3 - Drain your mash tun completely. Measure the volume for future reference.
Step 4 - Fill your mash tun with the amount of sparge water your calculated earlier. The temperature should be somewhere around 175 degrees. Stir the grain bed to get all those sugars back into solution, and let it sit for about 10 minutes.
Step 5 - Repeat Step 2 by draining and replacing 1 - 2 Quarts at a time until it is relatively clear. You will notice that, this time, your wort has less color than the last step.
Step 6 - Open the spigot and drain this volume into your boil pot. Again, measure the volume for future reference.
Alternate Technique 1 - The Mashout
If you would like to try to eek out a few more sugars from your batch sparge, you could try a mashout. This involves adding some hot water (185 degrees or so) at the end of your mash to raise the temperature and loosen things up a bit before draining. If you want to try a mashout, hold some of your initial mash water back, and, at the end of your mash, heat it up to about 185, then add it to the mash tun. Vorlauf (recirculate) and drain as described.
This step is not necessary by any means, but sometimes adds a few more sugars to the mix.
Alternate Technique 2 - The Double Sparge
Instead of dumping all of your sparge water in at once, you could split this batch into two parts and repeat step 4 above twice. You might need to do this if your mash tun is too small to hold the entire sparge volume. You might just want to do this in order to try to increase your sugar extraction percentage.
This is purely speculation, but this is something I have always thought. Let's say you have a glass that you are washing out and you dumped a whole lot of soap in it. If you have an equal volume of water to use to rinse it, it seems to me that two equal rinsings of half your rinse water would get more soap out of the glass than one rinse of the whole volume of water. I think the same might hold true for your sparge ... you're just rinsing the sugars off of the grain particles at this point. Some tests are certainly in order some day.
Batch Sparging - The Pros
There are several sparging techniques available because each method has its good points and its bad points. I am of the opinion that, for a homebrewer, Batch Sparging is the ideal technique.
Time Savings - Because you do not have to wait for the water to slowly drain into/out of the mash tun, batch sparging can save you a half hour or more on this step alone. We do this for fun, and the brewing process is plenty time consuming. Anything that shortens it is great in my book.
No Stuck Mash - In fly sparging, the grain bed can become compacted and stop draining. Especially with wheat an rye beers. This is a very frustrating situation to correct. With batch sparging, there is very little worry of this happening because of the volume of water flowing through.
Lower Equipment Cost - In order to fly sparge effectively, you need to have a mash tun designed to allow all parts of the grain bed to have liquid rinse them clean. This usually involves having a false bottom or specially designed manifold to achieve maximum efficiency. With batch sparging, your equipment design is not nearly as important. All you really need is a simple manifld made of stainless steel braid (toilet water line hose) and a simple spigot. Note: I will write an article in the future on just how to do this.
Less Tannin Extraction - When you fly sparge, there is some danger of extracting bitter tannins from your grains as the pH of the grain bed drops toward the end of the sparge. In batch sparging, you have no worries because the pH in the batch is constant, and does not reach down to those tannin extracting levels ever.
Batch Sparging - The Cons
If batch sparging were the holy grail, the pros would be doing it too, and it would just be called sparging. There are a couple of negative points to this technique. However, the pros far outweigh these.
Extraction Efficiency - In general, with a well-designed mash tun, you should be able to get more sugars into the boil kettle with fly sparging over batch sparging. This is great if you are a big-money brewery with those pesky accountants staring over your shoulder. However, you're small potatoes ... and with grain about a buck a pound, you can adjust your expected efficiency down a little bit and add a bit more grain to your recipe for not much cash. Yet again, you'll need your BeerSmith program to do this. My experience with batch sparging has been that I get anywhere from 65 to 75% efficiency from batch sparging (much of this having to do with the crush of the grain).
Cost - If you need a little more grain, it might cost a bit more per recipe, but not much.
Not as many cool gadgets - Maybe you like brewing because you like building all the neat gadgets. Sure, it is a lot more fun to design some cool false-bottom mash tun or your own manifold than just throw a stainless steel screen onto a spigot. It's your hobby, do what you like. Me ... I like beer.
