Spreading the Joys of Homebrewing Throughout Philadelphia and Its Suburbs

Stubborn attenuation

Hi all - in search of some advice here again...

I brewed a Blonde Ale on Saturday night, and ended up splitting the entire volume into 3 x 5 gallon batches. All batches had an OG of 1.060, which was right on target. My target gravity should be around 16, an attenuation rate of 73%.

#1: 5 gallons in a carboy. Used a smack pack of German Ale yeast. Gravity reading after 5.5 days is 20, and this one seems to well on its way to hitting the target

#2: 5 gallons in a carboy. On brew night I split half of a (not very active) starter with East Coast ale and then added a half of a vial of the same yeast after 12 hours. Gravity reading after 5.5 days is now at 23, and I'm hopeful that this will go down a bit more as well.

#3: 5 gallons in a bucket: I split the yeast(s) with #2, but for this one the gravity reading after 5.5 days is at 28.

For secondaries, one of these will go into a corny, the other two into carboys.

So here's are my questions:

1) In general, I seem to have a bit of a hard time getting close to my target gravity before I rack to secondary. I've tried starters, smack packs, vials, and dry yeast. What, if anything in particular, can I do to ensure better attenuation rates and avoid a slightly sweet beer

2) What ought I do to bring these Blonde beers down to their target gravities?

3) I have to rack one of them into the corny tonight, as I will be brewing several batches tomorrow and need the bucket. Which one is the best candidate?

4) How much longer should I wait for the others before I rack them into secondaries?

Thanks for any help and insight!

Eivind

PS: It's been a busy few brewing weeks. First 5 gallons of Oatmeal Stout, then 15 gallons of Blonde, and tomorrow it's 10 gallons of Altbier and 10 gallons of IPA..!

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Replies to This Discussion

Permalink Reply by Jeff Louella on September 18, 2009 at 11:56am: Give the beers a full 2 weeks in primary. Those last couple gravity points take the longest. But here are some things you can do. This will also be in my presentation on "Fermentation" at next meeting.

1) Add Sugar pure cane/beet sugar to the recipe. This ferments out 100% and helps dry out a beer. I put a 1/2 pound in every IPA I make.

2) Go All-Grain - When using extract, the liquid malt is produced to be average (possibly 1.050) for every style. The malting company is in the business for quality, but speed counts. They probably run their mashes at a higher temperature for quicker conversions. This reduces fermentability. Going all grain you can make the wort for the beer you want. Drier beers use a lower mash temp, sweeter more mouth feel beers use a high temp.

3) Yeast Pitch Rate and Viability - Sometimes yeast sits on the shelf for a couple months. Every day the yeast is sitting, the less viable it is. This is where a good starter helps out. Also the amount of yeast pitched. The bigger the beer the more you need. Here is a good calculator to figure out how much yeast you may need. http://www.mrmalty.com/calc/calc.html and then the science behind it here http://www.mrmalty.com/pitching.php

4) Fermentation Temperature Control - This is one on the most key areas. If your temperature fluctuates a couple degrees cooler over night, the early flocculating yeast may choose to floc out early. The warmer you ferment, the more active the yeast will be and the more they will attenuate, but the more off flavors you will have. I've had great success starting my fermentations at 66 degrees during the aerobic and lag phases. then raising the temperature a couple degrees during the beef of fermentation, the raising a couple more degrees at the tail end. Of course, you need a temperature controller and a heating cooling device. Good news is winter is near so we only need to keep it warm in those month and heating elements are cheap.

5) Stir the Yeast Cake - Gently stir up the yeast cake from the bottom to re suspend the yeast that floc'd to the bottom. This help get those last couple gravity points. this technique is needed with English style ale yeast that are high flocculating.; ▶ Reply to This

Permalink Reply by Eivind Sandstrand on September 18, 2009 at 12:10pm: Thanks Jeff!

I've had some luck with stirring the yeast cake in the past, so I'm trying that as my first step.

I'm interested in trying the addition of sugars if there hasn't been much more development in the next few days. How do you go about adding sugar - do you dissolve it in hot water and then chill it to the same temp as the fermenting beer? And how do you "stir it in", without risking splashing?

Thanks,

-e; ▶ Reply to This

Permalink Reply by Jeff Louella on September 18, 2009 at 1:55pm: I add all mu sugar into the recipe to be brewed. Sugar ferments 100%, but raises the ABV. So if your main recipe calls for 1.060 SG. Calculate the recipe to take x% of LME and replace with x% of sugar.; ▶ Reply to This

Permalink Reply by Dan Noon on September 18, 2009 at 1:14pm: Are you adding enough Oxygen? How are you going about doing that?
What's the temperature where you're keeping those? The German Ale finished first, so maybe it's too cold for the other yeasts?

If you're splitting a starter with two batches, you're probably not getting enough yeast. Take a look at the yeast calculator Jeff posted -- that'll be of help.

Wait at most 3 weeks for the Blondes.

I guess rack the German Ale, or just buy another bucket, brewing machine! You're on the fast road to burnout!; ▶ Reply to This

Permalink Reply by Eivind Sandstrand on September 18, 2009 at 3:11pm: Lots of oxygen and good healthy fermentation starts within hours of pitching. Temperature has been holding steady at 70-71F and that is a tad high for the German Ale yeast (which performed the best), and just right for the East Coast Ale yeasts (which had diverging performance.)

I split the starter between two carboys, but then also split a vial between them as well 12 hours later.

I'll probably rack one of the East Coast Blondes into the corny on Sunday and use that as a secondary, and then do a more traditional secondary in a couple of BetterBottles once I'm happy with the gravity.

No matter what happens, it'll be fun and educational to get three different beers from the same boil!

-e; ▶ Reply to This

Permalink Reply by Christian Mosebach on September 19, 2009 at 9:24pm: Make sure there is enough yeast being pitched. I usually err on the side of overpitching a little bit rather than underpitch. That's just what I prefer. And starters are great because you can make that up the night before with only 1 vial for average gravity beers, and by the time you're ready to pitch the next day, the starter is in active fermentation, your yeast population should be where it needs to be, and you're good to go!; ▶ Reply to This

Permalink Reply by Eivind Sandstrand on September 21, 2009 at 11:44am: Quick update, did another gravity read today, here are the numbers for comparison

After 5.5 days:
German Blonde: 20SG
East Coast Blonde I: 23SG
East Coast Blonde II: 28SG

Roused the yeast on all three vessels and bubbling continued at a slow pace, but could still see activity inside the carboys

After 7.5 days:
German Blonde: 19SG
East Coast Blonde I: 21SG
East Coast Blonde II: 23SG

Will leave them in primary for another 4-5 days and then rack to carboys and corny. Things seem to be going ok, just need to be patient, patient, patient...; ▶ Reply to This