Gravity problem

What went wrong? Was this supposed to happen? Should I throw it out? What do I do now?

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Gravity problem

Postby SantaFebrewer » Thu Oct 10, 2002 1:42 pm

I seem to be having a reoccurring problem with my gravity. I don't seem to be getting enough drop in the fermenting stage. My latest batch had an OG of 1.07, but only dropped to 1.021 by the end of fermentation. I am on well water, and I suspected that was the problem. I am adding a tablespoon of Lactic acid to the boil to compensate.

The beer tastes great, but I'm still puzzled why the yeast isn't eating all the sugars.

Any help is appreciated.

J
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Many variables at work

Postby jayhawk » Thu Oct 10, 2002 2:18 pm

While well water could affect the taste of the beer, I doubt it would impact the fermentability of your wort. The hardness or softness of the water could impact your mash if you are brewing all grain. As well, a higher mash temp (70C) will produce a less fermentable wort, thus producing a higher final gravity. Also, what is the process you use for aerating your wort? Do you prepare a yeast starter prior to pitching? What is the yeast strain you are using and is it appropriate for higher gravity brews? Post some more info and I am sure there will be no shortage of hypostheses put forward about your problem.
Good luck
Chris
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More info

Postby SantaFebrewer » Thu Oct 10, 2002 2:59 pm

Thanks for the reply.

I am using a wyeast. Usually I use the 1056 American Ale, but this latest batch I used the 1214 Belgian Ale wyeast. My aerating process involves pouring the cooled wort into the primary, though a sieve. This produces alot of air in the wort. Then I pitch the yeast in and cover the wort. i don't prepare a starter, except for popping the wyeast pouch and letting the pouch swell over night.

My latest batch was brewed using mostly DME, so little grain was actually mashed. The pound of grain that I did mash was done at 150 degrees for 20 minutes.

I should say that the fermentation usually begins in less than 12 hours, and it lasts several days with good co2 blowoff. Then, suddenly the fermentation stops quickly.

Thanks for helping a novice solve the mystery.

J
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Well..

Postby jayhawk » Thu Oct 10, 2002 3:14 pm

I don't think aeration is your problem, but I think that not preparing a starter, especially with high gravity batches, could affect the amount of fermentation. However, I do not have much experience with batches over 1.055. so I may not be the most reliable source here. It seems to me that preparing a starter is always the best way to go, regardless of OG. By not raising the yeast cell count high enough prior to pitching, the yeast colony may progress through its cycle without being able to fully ferment all fermentables. If you had prepared a starter, there would have been a higher cell count pitched, and therefore the larger colony would be able to consume more of the fermentables by the time it had progressed through its cycle. I hope this is making sense. If not, there are far more experienced people on the forum who will probably be able to offer more "expert" advice. Anyway that is my guess. Next....?
PS You should post the recipe you used for the batch, that always helps.
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3 steps to high attenuation

Postby Gravity Thrills » Thu Oct 10, 2002 6:42 pm

Jayhawk is right, make a starter and give your yeast a head start. he's also right about the higher grav wort being a little tougher to ferment out, and I think it's a combination of too little pitched yeast AND too little aeration. The laws of physics dictate that higher gravity worts hold less oxygen at saturation and are harder to saturate. Also, your underpitched and overworked yeast start to get sluggish as your alcohol content rises during fermentation. Also, if you are doing mostly extract and high grav, use 1-2 tsp. of Fermax or other yeast nutrient.

To sum up:
-make a yeast starter
-following your strainer aerating, go ahead and stir or shake the snot out of your wort for a good 5 minutes.
-use a yeats nutrient.

Doing these little things will clear up stuck fermentations 9 times out of 10.

Brew Straight and True
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Thanks for all the info, Y'all

Postby SantaFebrewer » Fri Oct 11, 2002 7:17 am

I'll keep you posted on the next batch.

J
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maybe there is no problem

Postby Monkey Man » Fri Oct 11, 2002 6:15 pm

Wyeast advertises the 1214 yeast to have an apparent attenuation of 72-76%. Assuming your readings were taken at or corrected to 60 degrees F, your apparent attenuation was 71%. I would attest that your beer did attenuate well, given the yeast style. If you want more of the sugar fermented try:
Using a starter. I frequently make batches well over 1.070- some as high as 1.096!. Definately use a starter culture for big beers. I would reccommend at least a quart.

Selection of yeast is very important also. It sounds like you want to use yeast that has a high attenuation rating. When selecting yeast another thing to look at besides attenuation is flocculation. More flocculant ale yeasts generally result maltier, clearer beers. Lesser flocculant ale yeasts generally result in drier, but often more estery and fruity beers. In addition, I would also echoe the advice on teh preceding posts. However, no matter how much aerating, stirring, sloshing, straining, propagating, culturing, viability testing, O2 injecting, vibrating, splashing, shaking, pitching, starter making, or cursing you do, if you are trying to make a dry beer with yeast that ferment relatively less sugar you are wasting time and energy. Yeast selection is paramount. Prost!
Nate
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