What is Lautering in Beer Brewing?

Discover what lautering is, how to do it, some troubleshooting tips and some options for homebrewing


Mat Stuckey

9/15/20233 min read

Beer Lautering in a mash tun
Beer Lautering in a mash tun

A Guide to Lautering in Beer Brewing

Lautering is a pivotal process in brewing that separates sweet wort from spent grains after mashing. Properly performed lautering provides clear wort for boiling and achieves target extract efficiency. Mastering lautering techniques is key for both professional and homebrewers seeking to craft optimised beer.

The Science and Objectives Behind Lautering

Lautering leverages the mash tun itself as a filtration system to remove liquid wort from the grain bed. This occurs after mashing has converted grain starches to fermentable sugars.

During mashing, hot water activates natural enzymes present in barley and other brewing grains. These enzymes break down complex starch molecules into simpler maltose sugars that yeast can ferment.

Once this enzymatic conversion is complete, lautering serves several important functions:

  • Separating sweet liquid wort by draining it from the grain solids

  • Rinsing and sparging grains with hot water to extract residual sugars

  • Filtering wort to remove grain particulates for clearer boil kettle transfers

  • Controlling wort clarity by eliminating proteins, tannins and lipids

  • Hitting target pre-boil gravity and volume through sparging and sugar extraction.

Well-performed lautering is crucial for producing filtered wort and achieving your intended original gravity. Without lautering,collected wort would be hazy and filled with grain sediment.

Step-by-Step Lautering Process Explained

While lautering equipment varies, the process follows a standard sequence:

  1. Recirculation and Vorlauf - The first runnings are recycled through the grain bed multiple times. This sets the grain filter while clarifying initial wort.

  2. Drain First Wort - Once recirculation is complete, the sugar-rich first wort is drained off into the brew kettle. This often equates to around one third of total volume.

  3. Sparge with Hot Water - Next, 168-170°F water is sprayed evenly over the grains to rinse additional sugars off the grains into the wort.

  4. Vorlauf Repeatedly - Every few gallons, wort flow is interrupted to recirculate and prevent grain bed channelling.

  5. Collect Final Wort - The sweet wort is drained until target volume and gravity are reached. Be sure to stop before extracting astringent tannins.

  6. Advanced lautering systems utilise continuous sparging for very high mash efficiencies exceeding 90%.

Tips for Efficient Lautering and Sparging

Achieving good lauter performance requires focusing on these parameters:

  • Grain crush - The crush must be uniform and relatively coarse. Too fine causes stuck sparges.

  • Grain bed pH - pH between 5.2-5.5 optimises enzyme activity and promotes wort runoff.

  • Recirculation rate - Vigorous recirculation helps clarify wort before draining first runnings.

  • Sparge water temperature - Sparging works best with water between 168°F - 170°F.

  • Sparge technique - Gently sparge over all grains evenly to rinse sugar without disturbing bed.

  • Vorlauf frequency - Recirculate every few gallons to prevent channelling and sediment.

  • Sparge duration - Halt sparge before extracting unpleasant grain tannins and astringency.

Lautering Equipment Options for Home Brewing

Advanced commercial breweries employ dedicated lauter tuns. But homebrew-scale options work well for smaller batches:

  • BIAB - With brew in a bag, no lautering is required. Simply lift the bag and drain.

  • Cooler Mash Tun - Affordable mash tuns come equipped with a spigot for lautering wort.

  • RIMS/HERMS - Automated recirculation systems allow multi-step mashing in one vessel.

  • 3-Vessel System - A separate mash tun and brew kettle enables sparging with hot liquor.

Basic mash tuns and BIAB provide effective lautering capability without expensive gear.

Potential Lautering Issues and Solutions

While usually straightforward, these potential issues can arise:

  • Stuck sparge - Very slow or stuck runoff. Fix by adjusting crush, pH, sparge rate, and grist composition.

  • Poor efficiency - Low measured OG indicates insufficient sugar extraction. Increase sparge duration or temperature.

  • Tannin extraction - Over Sparging can extract unpleasant grain tannins. Halt sparge sooner.

  • Cloudy wort - Sediment and particulates passing into boil kettle. Improve recirculation and vorlaufing.

Conclusion - Well-Performed Lautering is Key to Brewing Success

As a critical intermediary step between mashing and boiling wort, proper lautering technique helps ensure brewing success from the start.

By mastering the objectives, science, and methods of effective lautering and sparging, both professional and homebrewers can reliably produce clear, sweet wort perfectly primed for the boil kettle. This sets the stage for flavourful beers with the intended alcohol strength.

While lautering is often glossed over compared to flashier brewing steps, don't underestimate the importance of this liquid-solid separation process. A bit of focus on improving your lautering methods can pay big dividends in your finished beers!

Lautering beer at home
Lautering beer at home