Many Ways to Love Your Lauter

Fly sparge, batch sparge, no sparge, BIAB—we tested 4 sparging methods to help you decide which is best for you and your brew system.

Taylor Caron Aug 23, 2017 - 11 min read

Many Ways to Love Your Lauter Primary Image

Making wort can be dead simple or ridiculously complicated, but no matter how you mash it, it’s going to need to be separated from the spent grains before the boil. In this article we explore a few different ways to get that sweet goodness into the kettle.

A typical lauter begins by first raising the temperature of the mash (mash out), then recirculating the wort (vorlauf in German) to establish a filter bed and clarify the runoff, and finally rinsing (sparging) the grains to collect the available sugars in the boil kettle.

By first heating up the mash, we help the sugars from our first runnings into the kettle to flow more freely, giving us a better overall yield. Taking the extra time for a thorough vorlauf, we decrease the amount of grain particulates going into the boil, which otherwise would lead to unwanted levels of tannin astringency. Finally, our sparging method will largely determine just what percentage of the total available sugars we are able to capture in the kettle.

We each have our own set of goals and limitations, and often it’s the acceptable compromises that allow us to enjoy that lovingly made pint regardless of how it got into the glass. Let’s look at four different sparging methods and the pros and cons of each.


Sparging Methods in a Nutshell

First is the common fly sparge, whereby you gradually add water (often by sprinkling) on top of the grain bed as you drain from below. This will generally give you the most sugars out of a pound of grain, all else being equal.

But many excellent beers are made with a so-called batch sparge, where you simply divide up the remaining kettle volume after first runnings into “batches” of water that are stirred into the mash, revorlaufed, and drained, usually once or twice. This method may result in a slightly lower yield, but it can significantly shorten the time it takes to get the wort into the kettle. It is also much less finicky about the design of the mash tun.

Finally, for a no-sparge lauter, you simply add the necessary water into the mash right at mash out, vorlauf, and drain, lickity split. Again, the result is lower yield, but time is money, right?

Yes, maybe. Many of us consider that 5- or 6-hour island of Brew Day in life a sanctuary, and the extra time just isn’t that big of a deal. However equipment for a high-yield fly sparge can be a considerable investment. The would-be all-grainer can be set back upward of $150 to buy or build a well-functioning mash tun with a false bottom that won’t cavitate, clog, or encourage channeling of sparge water without rinsing the grains well. A simpler sparging method can circumvent the need for an excellent false bottom, using a simple stainless screen tube or even a nylon “brew in a bag” insert.


The Test

For our test, we used a pretty typical system for many all-grain homebrewers. It’s a three-vessel system with a pot for heating brew liquor, a mash tun (in this case, an insulated cooler), and the boil kettle itself.

To dig deeper into the details of the sparging techniques, we conducted a fairly simple brew, iterated four ways: fly sparge, double-batch sparge, no-sparge, and then a modified no-sparge using a brew-in-a-bag (BIAB) nylon bag. All but the last brew were conducted in an Igloo Ice Cube with a slotted manifold of copper tubing.

For the mash, our friends at Root Shoot Malting (Loveland, Colorado) were kind enough to donate a 50-pound sack of Odyssey Pilsner malt, so, of course, we used an even 12.5 pounds per batch because why not! Vorlauf was simply “until it runs clear,” which in this case did not take long at all. The table below summarizes the differences between the four mashes regarding lauter times, yield, and comments on the finished beer.


Efforts were made to keep the recipes as similar as possible, so the lower-yielding batches were boiled longer to reach OG before adding hops, and hopping rates were decreased according to the volume.


Fly Sparge

On the benchmark fly-sparge run, we got the usual 5.5 gallons in the fermentor at a specific gravity of 1.065, a respectable 80-ish percent mash efficiency even with the slightly higher than optimal pH of an all-Pilsner grist in our pure mountain runoff. The Root Shoot Pilsner did a fine job of running clear after minimal vorlauf and smelled inviting in the kettle. Between the 10 minutes recirculating and the full 45-minute sparge, it was awfully close to an hour from mash out to boil, firing up the burner midway.

Batch Sparge

Our double-batch sparge obviously necessitated vorlaufing three times, but with each runoff going full blast, we had our kettle volume in about 35 minutes. Using the same volume of sparge water as for the fly-sparge, our mash efficiency dropped to about 74 percent, which is actually par for the course on this system. To compensate, we simply boiled 20 minutes longer to bring our pre-boil gravity up to match the fly-sparge brew before adding the hops and adjusted the hops for a slightly lower volume of about 4.6 gallons in the keg.

No Sparge #1

For the no-sparge effort, we first used the same mash tun as for the other two brews, but at mash out, we diluted the mash to reach our pre-boil gravity, recirculated until clear, and dumped. Sadly but not surprisingly, our yield dropped through the floor to an underwhelming 64 percent mash efficiency! With static volume losses through the kettle and primary, the overall brewhouse efficiency was heartbreaking. That said, it was certainly the easiest and least time-consuming method, taking all of 15 minutes from mash out to flame on.

No Sparge #2

The second no-sparge effort was a BIAB. The no-sparge version in the mash tun definitely allowed a much clearer wort into the kettle, but to mitigate the dusty nature of BIAB, we allowed it to stand an additional 20 minutes before judiciously siphoning into the kettle, losing nothing to speak of in volume compared to the mash tun no-sparge. Both of these final batches gave us about 4 gallons in the end.


The Results

All four of the beers finished fairly dry at 1.010 give or take. The fly-sparged version dropped clear much faster than the other three, possibly an effect of less tannin going into the kettle or lower pH. This would have been an interesting parameter to measure. Not surprisingly, the batch-sparged wort with its longer boil had a slightly deeper gold highlight, but the flavor was very similar. There was a low level of astringent harshness in the BIAB version not found in the others, likely just from grain particulates making their way into the boil, but the less-than-scientific hops bittering adjustment to the smaller boil may have contributed as well. All things considered, the differences noted between the four methods were near what might be expected in even small-batch variations using the same lauter technique.

So which method is best? That depends on you, how valuable your time is, what your budget for ingredients and brew equipment looks like, and the sorts of beers you like to brew.

At one level, there is a trade off between time and cost of the grain. Minor differences in flavor and clarity aside, just what did the time savings of the lower yield cost us in terms of grain? In the worst case, we got about $0.80 on the dollar for our no-sparge brew compared to the fly-sparge brew. If we say a pound of malt costs $1.50, then this $18.75 grist will cost us almost $23.50 to produce with our no-sparge method, but we can save almost 45 minutes in a brew day. (Keep in mind that this sort of wort made with extract might run closer to $33!)

The other factor is equipment cost. If you have the equipment to follow a fly-sparge regimen, it will definitely pay off on bigger mashes. However, having run many double-batch sparges and a few no sparges through this same system, I can say with certainty that the disparity between fly sparging and other methods decreases with smaller grists, so for the average 1.052–1.056 OG wort, that same efficiency loss would be only a mere $4 or so. If you value your time, you may do better to drop a few extra bucks for malt. If you’re like many of us and already have a large cooler sitting lonely in the garage pile, it’s a fairly simple thing to throw on a valve and remedial filter screen and get to batch sparging while perhaps saving your milk money for a nice false bottom and sparge-arm assembly.

The BIAB method has honest cost advantages for the beginning all-grainer who already has a 6.5 gallon fermenting bucket, an Army blanket, and a large mesh bag. The BIAB method adds only a small amount of actual work to the brew day compared to an extract batch, and the overall footprint of equipment to store in between brews is much less. If this makes the difference between someone continuing to stir syrup into a pot and taking the leap into making fresh wort, I am all for it. Get brewing!

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