Aeration and FG

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iglehart

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I have now done about 5 all grain BIAB and I am very happy with the results. I do have one issue and I am wondering if the problem is not aerating my wort.

In all of my recipes my FG only gets down to 1.20 to 1.22.
Some started as high as 1.072 some as low as 1.050.

I have tried different yeast, but mostly the same procedure, so I think I can rule out the yeast.

I have 2 thoughts to what might be the issue, which one should I try first.

1. I aerate by pouring the wort into the fermenter, thats all.
I am thinking of getting an aeration stone. I have the pump and tubing already.

2. Something with my procedure is causing the FG to be high. Not sure what, but I will have to do more research.

Any thoughts? I am leaning toward #1, could a bad aeration cause low FG.

Also, all my beer got off to a quick fermentation and vigorious fermentation.
I have used dry yeast and liquid yeast.
 

Double_D

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If you're mashing in the 154-158 range you would see high finishing gravity like that. But otherwise, it's not usually associated with aeration. If you had slow lag time or stalled fermentation I'd say you need more aeration. Aeration is especially important for high gravity beers however, but that's because the initial growth phase of the yeast colony in aerobic.

So, what temp have you been mashing at?
 
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iglehart

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Depends on the recipes, most of them I do a step.
120-125, then 150-155. My procedure is not the exacting. I do like maltier beers so I try to stay at 155. I have never overshot by more than 1 or 2 degrees, but I have let it cool down to 145 or 146 a few times.
 

Double_D

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The lower temp would give you a thinner body theoretically. Conversion happens quickly with most of the modern base malts to if you mash in too high, you're pretty much locked in. Have you been using a high percentage of character malts like crystal or something?
 
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iglehart

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So most of the recipes have oatmeal or a good % or Brown, Crystal or Abbey malt.
Base malt only accounts for 50-70% of the grain bill.
 

Double_D

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That's your problem then. Start keeping your character malts below 25% of the total grist weight. You'll have more than enough to work with. Not sure I've seen abbey malt though. It that like belgian pils or something else?
 
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iglehart

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Abbey Malt (Weyermann®)

This pseudo-base malt will add great color and pronounced malt aroma and flavor. Great for Traditional Abbey Ale, Trappist, Belgian Blonde, Amber and Brown (bruin), Fest Beer, and Fruit beer.

EBC: 40-50
Lovibond: 15.5-19.2
Usage: to 50%
Moisture:: 4.5 max %
Total nitrogen::
Extract% (dry basis): min 75%
Soluble Nitrogen Ratio:

Brown Malt was the origingal dark malt back in ye olde days. It will add a nutty, biscuity and slightly smoky flavor in addition to the roastyness. Use 2 to 10% (or up to 50% if making a traditional Porter).

Avg. Lovibond: 65

Origin: UK

Caramunich II (Weyermann®)

German crystal malt. Adds maltiness, aroma, color.

EBC: 110-130
Lovibond: 42-49
Usage: to 10%
Moisture:: 5.5-6.5%
Total nitrogen:: 10.5-12.5%
Extract% (dry basis): 70-74
Soluble Nitrogen Ratio: N/A

Last recipe which got to 1.022 from 1.072
Had 5lbs Munich
2 lbs Abbey
1 lb Honey
1 lb Caramunich II
 

chriscraig

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I'm going to say that your problem is under-pitching. A packet / vial of yeast would be good enough for a 1.050 beer, but you'd need to double up for something as big as a 1.070 beer. It has to do with attenuation.
 
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iglehart

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FYI for pitching rates. I use a packet but I am brewing 2.5 to 3 gallons.

Do I need to pitch more yeast for gravity or by volumn of beer.
I figured the higher gravity would be ok because of the smaller volumn.
 
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iglehart

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Sorry I did not use the Brown Malt I used


Honey Malt (Gambrinus)
Honey malt is Gambrinus Malting's best description for the unique European malt known as brumalt. Its intense malt sweetness makes it perfect for any specialty beer. It is devoid of any astringent roast flavors. In addition to its intense malt sweetness it adds a nutty-sweet and slightly toasted flavor and a slightly honey-like aroma.

Use up to 20%

Avg. Lovibond: 25

Origin: Canada
 

ChiechiBrouw

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Second for the aeration stone. Since getting one my fermentations have become way more reproducible, removing that variable from the beerquation.

I actually just brewed an 8% stout and it attenuated perfectly!
 

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