Skip to main content

Don't be afraid of the Trub!

In a lot of home brewing books, and perhaps in the minds of many home brewers, is the advice that you should separate your beer from the trub during fermentation.  (Trub, also known as lees, refers to the sediment that appears at the bottom of the fermenter.) The prevailing wisdom is that trub will cause the finished beer to be more cloudy, have "off flavors", and generally turn out worse than a beer moved off the trub into a secondary fermenter.

The folks who make the Grainfather did an experiment in February to see if the prevailing wisdom is correct.  Would a beer kept on the trub throughout its fermentation taste worse, look more cloudy, have poorer head retention, etc., than a beer removed from the trub?

For the experiment, they brewed an American Pale Ale (APA).  Half of the batch was fermented with as little sediment as possible.  The other half was given as much sediment as possible.  If the trub made any difference in the beer, this experiment should make that difference very obvious.  Their recipe for the APA was:

  • 4.5 kg pale malt
  • 1 g Simcoe hops at 60 minutes
  • 150g of Simcoe hops at whirlpool
  • Mangrove Jacks Burton Union yeast

After brewing, half the batch was poured through a sanitized sieve to strain all possible particulate matter out of it.  The other half got all the trub when it went into the fermenter.

The beers fermented identically, starting with a gravity of 1.044 and ending with 1.005.

After 7 days, the fermenters were moved to a refrigerator to cold crash them before bottling.  After chilling, another gravity measurement was taken to ensure that gravity had remained the same.  It had.  A quick taste test showed that the sample from the trub-filled fermenter actually was more bitter than the one from the trub-free fermenter.

They got 14 bottles from the trub-filled fermenter and 18 from the trub-free one.  So if you want better yields, avoiding trub is a good idea.

A blind taste test was then performed of the two beers after bottle conditioning.  Tasters were asked to judge the clarity, aroma, head retention, and comment on any off flavors they detected.  The results were surprising.

The beer brewed with the trub was judged to be clearer by all four tasters.  It was also judged to have the better aroma.  Tasters were split 50/50 on head retention, but all agreed that it was similar for both beers.  But home brewers probably care most about flavor...  how did that turn out?

All four tasters preferred the beer fermented with the trub.  They said its flavors were clearer and more defined than the beer fermented without trub.

When asked to guess which beer had been fermented with trub, all four were wrong.

The conclusion arrived at by the brewer were that a high proportion of trub can be beneficial.  It can improve clarity, aroma, and flavor.  The downside to leaving the trub in is that it did reduce their yield by 22%.  Perhaps it would be good to reduce trub but not eliminate it when homebrewing.

Whether you choose to leave the trub in your beer during fermentation or not, the good news is that you shouldn't have to worry if you can't get it all removed.  Your beer may actually benefit from a little trub making it into the fermenter.





Comments

Popular posts from this blog

Yellow Label Angel Yeast vs. Typical Brewing Yeast

I currently have my second batch of rice wine fermenting with the "magical" yellow-label Angel Yeast from China, and wanted to share some of the more unusual aspects of using it.  If you've never seen or used this yeast, I suspect you're not alone.  It ships in a 500 gram package that looks like this: What makes it "yellow label" is that yellow box you see in the upper left corner of the package.  This implies that it's yeast for distilling (though you do not need to have a still or distill the output to use it).  As I understand it, inside the package is a mix of yeast and other materials which will convert starch into sugar and directly ferment it, without the need for a traditional mash step.  This can radically shorten your brewing time.  For my most-recent batch of rice wine, I heated 3 gallons of water to 155F, poured it over 13+ pounds of uncooked rice straight out of the bag, let that soak for an hour, rehydrated some of this yeast in warm water,

2021 Batch 1 - Rice Wine made with Yellow Label Angel Yeast

I've become a big fan of the Still It channel on YouTube.  About a month ago, Jesse posted a video about how he made rice wine using nothing more than water, rice, and a purported "magic" yeast from China called Yellow Label Angel Yeast. Perhaps even more amazing was the fact that he was able to make the rice wine without gelatinizing or mashing the rice.  He shows three batches in the video.  One was made by cooking the rice before adding the yeast mixture. Another was made by adding uncooked rice to boiling water.  The last was made by adding uncooked rice to room temperature water.  All three fermented out to roughly the same amount of alcohol in about two weeks. He was amazed by this, as was I. I resolved to buy some of this magical yeast from Aliexpress.com and try it out. In the Still It video, the rice is ground up in the grain mill into smaller chunks to make it easier for the enzymes in the yellow label yeast to convert and ferment.  I'm changing this up s

Making Alton Brown's Immersion Cooker Fennel Cardamon Cordial

Alton Brown's "Good Eats" series is my favorite cooking show.  I love the way he explains the "why" and "how" of a recipe in detail, which helps you understand (if things don't go right) where you may have gone wrong.  In his episode on immersion cooking (also known as sous vide), he shows you how to make a cordial in an hour using an immersion cooker. It took me a while to locate all the ingredients here in Columbus.  I ended up getting the fennel and vodka at Giant Eagle. The cardamom seeds, pods, and anise stars came from Amazon.  The Fennel fronds and bulb came from Trader Joe's at Easton. Ingredients 32 ounces of 80-proof vodka 2 cups of fennel fronds 10 green cardamom pods 3 ounces granulated sugar 1 tablespoon fennel seeds 1 teaspoon black cardamom seeds 1 whole star anise Begin by loading your sous vide vessel with hot water and set your immersion cooker to 140F. While the cooker is getting up to that temperature, meas