Lautering and the Length of Your Brewday


Heating your wort as you collect it saves time on brewday.

In the previous article, I discussed when you can safely stop mashing and proceed to the mash out and recirculation steps. Heading to the next step when an iodine test indicates that the mash is converted can frequently save you at least 20 minutes out of the usual 60-minute mash time specified in most homebrew recipes. Today I present another way to save time in your all-grain brew day — pick a lautering method that makes sense given how quickly you can heat your wort.



Lautering is the step in all-grain brewing in which the brewer separates the sweet wort from the spent grains. Most forms of lautering involve sparging — rinsing the grain bed with hot water. This extracts sugars from the grains that did not freely drain along with the first wort. (The first wort comprises all the runnings from the lauter tun that are undiluted with sparge water.)

Continuous Sparging

The most common kind of sparging practiced by commercial breweries is continuous sparging. In continuous sparging, sparge water is added to the top of the grain bed at roughly the same rate as wort is drained from the lauter tun. (Sometimes the water is added in “pulses,” a technique that make continuous sparging easier in a home brewery.) When using continuous sparging, the more slowly you lauter, the better extract efficiency you achieve. Many introductory homebrewing texts urge brewers to take around 60 minutes to lauter, and some homebrewers who are chasing very high efficiencies extend this to 90 minutes or more. Homebrewers often refer to continuous sparging as fly sparging.


Batch Sparging and No Sparge Brewing

If you’re not worried about achieving the maximum level of extract efficiency, you have several options, including batch sparging or no-sparge brewing. Brewers who batch sparge, or practice no-sparge brewing, collect their wort much more quickly than brewers who use continuous sparging. The extract efficiencies they achieve are slightly lower than typical extract efficiencies achieved by continuous spargers.


The Catch

However, the time saved in wort collection by batch sparging does not all translate into time saved over the course of the brew day. If you collect your wort quickly, you then need to heat it to a boil. However, if you collect your wort via fly sparging — but heat it as you collect it — you’ve merged wort collection and wort heating into a single step. If a batch sparger took 10 minutes to collect his wort, but then 20 minutes to heat it to a boil, a fly sparger could keep his brewday the same length by collecting his wort over 30 minutes, as long as he heated it while collecting and brought it to a boil the instant wort collection finished.


For Fly Spargers


You don’t need to exactly balance the input of water to the lauter tun with the outflow of wort; you can add water in pulses.

If you fly sparge, keep in mind that you aren’t necessarily spending that much more time on brew day than a batch sparger. If you heat your wort as you go and allow the temperature to creep up to boiling just as you’ve finished sparging, you’ve merged sparging and wort heating into a single step.

Also keep in mind that the loss of efficiency that comes with running off your wort more quickly is not linear. For example, if you get 80% extract efficiency by running off your wort in 60 minutes, it won’t be 40% if you run off the wort in 30 minutes. (It’ll probably be more like 75%.) Batch spargers run off their two worts as fast as they can and only get marginally poorer extract efficiencies. If saving time is something you desire, and you don’t mind a small decrease in extract efficiency, try collecting your wort over 30–45 minutes.

For the absolute fastest lautering, start running off the wort at your normal pace and then light your burner once you’ve got a couple quarts collected. Adjust the burner to the level you would normally use to heat your kettle. Keep running off wort at your normal pace as the kettle temperature climbs. Then, as the wort approaches boiling, increase the flow of your runnings so new wort from the lauter tun keeps the kettle at just below a boil. When you quit collecting wort, the wort will come to a boil. (When I do this, I shoot to keep the kettle temperature around 200–210 °F/91–95 °C, rather than on the edge of boiling.)

Of course, you don’t need to go as fast as you can. Pick a lautering time that seems like a good compromise between extract efficiency and time spent and go with that. (For me, collecting the wort over 45 minutes is a good tradeoff when time is of the essence.) Keep adjusting the heat as you go and keep the wort near boiling and you can be boiling a few moments after you’ve collected your target pre-boil volume.


For Batch Spargers

Once the first batch wort is run off, begin heating the wort in your kettle. Keep in mind that you will not lose any time by not immediately running off the second batch. You can wait until the first batch is nearly at a boil to do that. The extra contact time between the sparge water and the grain bed might let you eke out a little more sugar from the grains. You could even run off the second batch just fast enough to keep the kettle below a boil.


Lautering and Time

A speedy brewday is not always a priority. However, most all-grain homebrewers will face a time when they have to get a beer done in a shorter amount of time than usual. If you’re an all-grain brewer whose first priority is to keep the time of your brewday down, but not sacrifice quality, what lautering method should you choose? It depends on how quickly you can heat your wort. If your combination of burner output and batch size mean that you can bring your full pre-boil volume to a boil in a short amount of time (under 30 minutes), then batch sparging is a good option. You can quickly run off the wort, quickly get boiling and get your brewing done relatively, well, quickly. The only downside is that your extract efficiency may be slightly less than if you would have fly sparged. On the other hand, if it’s going to take you 30 minutes or more to bring your wort to a boil, you might as well continuous sparge and reap the benefits of slightly better extract efficiency.


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