Stuck Ferm or Low as it Goes?

[steevinhaze]

I don't know if my fermentation is stuck, or it's just as low as it's going to get. The two things I can think of are my wort is just not very fermentable, or the yeast I used is too flocculent. (Or maybe I wasn't sanitary enough while brewing, would that cause low attenuation?)

Measured OG was 1.054, and three days later I checked the gravity and it came out to 1.022. The yeast seemed to be completely flocculated, so I swirled to get them back into suspension. (After only 30 minutes or so, the yeast was all back on the bottom.) Three days later, checked again and it was still at 1.022. This means I'm only at 59% attenuation, that seems much too low. I was hoping for a FG of 1.014 or so.

Should I repitch yeast? If so, I don't have any yeast on hand, so how long is too long to wait to repitch?

Should I just keep swirling? If so, what's the best way to get yeast back into suspension without aerating too much? And how often should it be done?

Or is this just as low as it's going to go? Maybe the specialty grains and dark malt extract may have given me a higher final gravity than I was expecting. Here's my yeast and fermentables:

Yeast: Fermentis S-04

1.00 lbs Flaked oats
0.50 lbs Chocolate malt
0.50 lbs Torrefied wheat
0.50 lbs Black roasted barley
1.50 lbs 2-Row
6.00 lbs Dark LME

 

[theredben]

Don't worry about your sanitation procedures. If you had an infection you would end up with a lower FG because those other microbres can eat lots of things brewer's yeast can't digest.

What was your Partial Mash temperature? Did you treat this as just steeping grains like Crystal Malts?

 

[steevinhaze]

Partial mash temp was at 160. At first, after the grains were added the temp was only at 150 for about 15 minutes, but then I raised it to 160 for the last 30 minutes. My sparge was also at 160.

My intent was to mash, not just to steep, but honestly the difference between the two sometimes confuses me. I threw all my grains (two row, barley, wheat, chocolate malt, and oats) into a grain bag, and let them sit at 160 degrees for 45 minutes. After that, took the bag out and placed it into a different pot of water and let them sit at 160 degrees for 15.

 

[Vance71975]

Partial mash temp was at 160. At first, after the grains were added the temp was only at 150 for about 15 minutes, but then I raised it to 160 for the last 30 minutes. My sparge was also at 160.

My intent was to mash, not just to steep, but honestly the difference between the two sometimes confuses me. I threw all my grains (two row, barley, wheat, chocolate malt, and oats) into a grain bag, and let them sit at 160 degrees for 45 minutes. After that, took the bag out and placed it into a different pot of water and let them sit at 160 degrees for 15.

Check your gravity 3 days in a row, if it stays the same all 3 days your done. that being said, i give all beers 1 month in primary just to let the yeast do its job. If your mini mash was at 160, chances are you got very few fermetables.So likely it is done.

 

[jkreuze]

Are you sure your hydro reading was correct for the starting gravity?

I ask because you have four pounds of grains in your minimash and six pounds of LME. As a point of comparison, the Midwest Supplies Amber Ale kit has:

6 lb. Gold liquid malt extract, 12 oz. Caramel 40L, 2 oz. Special B, 2 oz. Roasted Barley specialty grains, for an expected SG of: 1.042-1.046 (this is from their website).

You have the same amount of LME but another 3-4 pounds of grain in your minimash to take into account.

I ran your recipe through an original gravity prediction tool (http://www.tastybrew.com/calculators/gravity.html), assuming 90% efficiency due to being mostly LME, and it came up much higher than 1.054--around 1.070. 1.022 isn't out of the realm of imagination if you started at a higher OG.

Just an idea

 

[steevinhaze]

Check your gravity 3 days in a row, if it stays the same all 3 days your done. that being said, i give all beers 1 month in primary just to let the yeast do its job. If your mini mash was at 160, chances are you got very few fermetables.So likely it is done.

1) Even if the gravity stays the same, meaning fermentation is complete, you let the beer sit in primary for a month to let the yeast do it's job. If fermentation is complete, what other job does the yeast do? I've read that it "cleans up after itself" and improves the flavor a bit. Is that what you're talking about?

2) You say if my mini mash was at 160, chances are I got very few fermentables. What should it have been at?



Also, it sounds like nobody really thinks I should try and repitch or swirl. I should just let it sit in primary for a couple more weeks, and then bottle?

 

[Vance71975]

1) Even if the gravity stays the same, meaning fermentation is complete, you let the beer sit in primary for a month to let the yeast do it's job. If fermentation is complete, what other job does the yeast do? I've read that it "cleans up after itself" and improves the flavor a bit. Is that what you're talking about?

2) You say if my mini mash was at 160, chances are I got very few fermentables. What should it have been at?



Also, it sounds like nobody really thinks I should try and repitch or swirl. I should just let it sit in primary for a couple more weeks, and then bottle?

Yes, the yeast will clean up some of its by products and improve the taste of the brew. It also allows more yeast to drop out thus making a clearer beer.

Ok the reason i say you likely got very few fermentables is this, when brewing all grain, Mash temp controls to an extent how fermentable your wort is, if you mash Low, say between 148-150 you get a wort that is more fermentable and has less body, 152-154 gets you a medium body beer, and medium fermentablity, 156- 158 you get a full body beer with less fermetables but more complex sugars. The point to a higher temp mash, is to get a thicker more "chewy" beer if you will, Now when you start getting above 158, you are really running a risk of starting to denture enzymes before they have had time to convert the starches to sugar. If your doing mini mashing, i personally would stay in the 150-154 range,depending on how much body your shooting for.

Yes i would not re-pitch on this one, because i feel from what you have said it would just be a waste of yeast. Give it time, Swirl the yeast daily without opening the fermentor and give it a month total time in primary, and you should come out with a nice full bodied beer.

 

[Calder]

The LME by itself would give you a 1.043 gravity beer. Your reading of 1.054 is either wrong, or you did something seriously wrong with your mash. 4 lbs has the potential to add another 21 points (at 75% efficiency) to your gravity giving you something around 1.064.

One of the differences between a steep and a mash is the volume of water. If you use too much water you will get a low efficiency.

My thoughts:

1) You got a bad reading (all ingredients were not mixed), and you really had a 1.064 OG. 1.022 is not too far off what you should expect since you mashed at a high temperature. It's about 65% attenuation. OR

2) The wort temperature is low and the yeast has dropped due to temperature. Move it to a higher temperature location and then rouse the yeast.