Finishing gravity always lower than projected

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ssspargur

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I have done a few beers in a row now, and all have finished lower than I want, and couple of them taste thin and need more body. I've been trouble shooting this for a while. I can't nail down if it's the yeast choice, mash temp, or ingredients I need to adjust? I use Beersmith.

Last brew Blue Moon clone (for all the haters in my life)
6lb Pale malt
5 lb White Wheat
1lb flaked oats
mashed at 154F for 60 min in cooler mash with braided hose.
OG 1059
FG predicted 1014-Actually finished at 1010
WLP001 Cal Ale
I nailed the OG on the money and mash held temp within a degree after an hour. However it finished at 1010

Blonde Ale
10.25 lb Pale Malt
7.2 oz Crystal 15
mashed at 153F for 60 min in cooler mash with braided hose.
OG 1051
FG predicted 1012-Actually finished at 1008
WLP001 Cal Ale
I nailed the OG on the money. Mash temp fell 4 degrees over and hour on this one. It finished at 1008

I've heard WLP001 is an over-achiever. So possibly I need to add some carapils to combat this. Or possibly raise my mash temps though I've had great success with Beersmith in nailing mash temps. And mashing into the 155-158 range seems crazy for beers of this style. Or possibly WLP001 is just a maniac, and I need to try WLP002 or something. Any advice appreciated.
 
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ssspargur

ssspargur

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I have up against my meat thermometer I used for grilling. They both read the same within a degeree. I have not done an icebath or anything more involved.
 

mcartt11

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Cali Ale yeast is a beast and always goes really low for me. Try same recipes with a different yeast and see if it produces something more to your liking. I have used London and European Ale yeasts in my Blondes in place of Cali and it definitely brings up the FG a few points.
 

kyle187

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How long from when your done mashing until you start boiling? If you aren't mashing out and theres a good amount of time before you begin to heat the wort for the boil, then the enzymes will continue to break down the sugars/starches and your wort will become more fermentable resulting in a lower final gravity. Maybe this could be the cause of your problems? I believe the point of mashing out is to "lock in" your fermentability.
 

Temp81

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Also look at fermentation temps. Obviously yeast strains have desired temps, but if you ferment on the cool side, and maybe cold crash a point or two higher than your desired gravity it may balance out to what you want.
 

D-Train

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How long from when your done mashing until you start boiling? If you aren't mashing out and theres a good amount of time before you begin to heat the wort for the boil, then the enzymes will continue to break down the sugars/starches and your wort will become more fermentable resulting in a lower final gravity. Maybe this could be the cause of your problems? I believe the point of mashing out is to "lock in" your fermentability.
^ This. It's taken me almost a year of AG brewing to realize how mash out or lack thereof affects my system, and I have a similar setup as you (cooler mash tun, batch sparge). Nice to know for styles that call for higher or lower FG.
 
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ssspargur

ssspargur

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I batch sparge with 168F. Let it sit after stirring for 5 minutes. Then drain pretty slowly. I do wait for my boil kettle to fill completely before I take some pre-boil gravity measurements. (I felt that was necessary to get an accurate gravity reading.) So I guess I am taking a fair amount of time before boiling.
 
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ssspargur

ssspargur

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Anyone who batch sparges out there.... Do I need to be draining slowly. I do recirculate about 2 quarts. But should I just open her up after that?
 

hannibalmdq

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Anyone who batch sparges out there.... Do I need to be draining slowly. I do recirculate about 2 quarts. But should I just open her up after that?
No need to hold it back. All the sugars are mixed into the solution when you stir up the sparge water and the grains. If you mixed it thoroughly, you should be able to run it off as fast as your system will allow.
 
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ssspargur

ssspargur

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So what's confusing me about "mashing out." is..... In my setup with a cooler and batch sparging. After I batch sparge with 168F, my grain bed raises to about 158F. So I dilly-dally draining and getting the boil started. With the higher temp shouldn't I be generating more UNfermentable sugars? The stuff that gives your beer body? Or are you saying there is still enzymes at work in my wort causing those to become fermentable? Losing it here.
 

hannibalmdq

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So what's confusing me about "mashing out." is..... In my setup with a cooler and batch sparging. After I batch sparge with 168F, my grain bed raises to about 158F. So I dilly-dally draining and getting the boil started. With the higher temp shouldn't I be generating more UNfermentable sugars? The stuff that gives your beer body? Or are you saying there is still enzymes at work in my wort causing those to become fermentable? Losing it here.
That's not entirely accurate. Conversion is reference the breakdown of starches into sugars. That's job one of the enzymes. They do this by hacking at the bonds of the starches and shortening them.

However, both Alpha and Beta amalyze will continue to break down those shorter sugars. Alpha Amalyze is limited compared to Beta in that it can't break some bonds and will leave more dextrins in the finished wort.

You aren't creating sugars the whole time your mashing. Once there is no starch left, you have all the sugars you're ever going to have (unless you dump some in). The alpha and beta amalyze will continue to break those sugars down until they denature (beta rapidply above 150, alpha above about 165).

So in your case, enzymatic breakdown will continue and the worts fermentability will continue to increase if you are only raising the temp to 158 during your mash out/sparge infusion. In fact, that's kind of the happy zone for alpha.
 

jakenbacon

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So what's confusing me about "mashing out." is..... In my setup with a cooler and batch sparging. After I batch sparge with 168F, my grain bed raises to about 158F. So I dilly-dally draining and getting the boil started. With the higher temp shouldn't I be generating more UNfermentable sugars? The stuff that gives your beer body? Or are you saying there is still enzymes at work in my wort causing those to become fermentable? Losing it here.
Yessir. Also remember that even if that wort is coming out at 158, when it touches that nice cool kettle bottom I bet the temp drops dramatically....
 
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ssspargur

ssspargur

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Ok this is much clearer now thanks so much. So I guess I need to speed up my batch sparge. Or "mash out" with water that'll get me closer to 170F. I've read a lot of people fearful of overdoing that and creating astringency from the grains. Any votes for either one? Thanks again.
 

hannibalmdq

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Ok this is much clearer now thanks so much. So I guess I need to speed up my batch sparge. Or "mash out" with water that'll get me closer to 170F. I've read a lot of people fearful of overdoing that and creating astringency from the grains. Any votes for either one? Thanks again.
Either will work. It shouldn't take very long to figure out what temp water you need. A lot of people just do 180 F. If you combine that with a quicker runoff you'll probably be able to control your attenuation.

The other, lazier, less traditional option would just be to cut your mash shorter. The enzyme are in the solution, so if you run off and start heating earlier the activity can just continue in your kettle.

There are many roads you can take when brewing.
 
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ssspargur

ssspargur

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So in the interest of speeding things up, I do actually need to get the entire volume of wort into the boil kettle to measure pre-boil gravity accurately? Yes?
 
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D-Train

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Even if you batch sparge with water hot enough to raise the grain bed to mash out temps, you're still draining first right? My understanding is those first runnings would need to be heated to lock in the fermentability, otherwise the enzymes will continue to break down and create more fermentable wort.
 

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Ok this is much clearer now thanks so much. So I guess I need to speed up my batch sparge. Or "mash out" with water that'll get me closer to 170F. I've read a lot of people fearful of overdoing that and creating astringency from the grains. Any votes for either one? Thanks again.
To extract tannins, you need temp over about 170°F, AND pH above about 6. If you acidify your sparge water to a pH of 5.6 or lower, you don't have to worry about tannins.

Brew on :mug:
 

hannibalmdq

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Even if you batch sparge with water hot enough to raise the grain bed to mash out temps, you're still draining first right? My understanding is those first runnings would need to be heated to lock in the fermentability, otherwise the enzymes will continue to break down and create more fermentable wort.
Yep. Your runnings will change gravity over time (alternatively, your batch sparges will have a lower gravity than the main mash). So you need to incorporate everything in the kettle and homogenize before determining your pre-boil Gravity.
 
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ssspargur

ssspargur

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Can't thank you all for the info enough. As I try to advance my brewing technique, the concept of managing my FG as it effects body and balance has really been a blind spot for me. I never thought the enzymes continued their job once wort was in the kettle. I also thought it was important to really drain the tun slowly. I knew mashout was important, but always read that batch-spargers didn't have to be concerned with it. Now looking back I can see taking 30 mins or more to completely fill boil kettle. Then starting the boil. I'm going to batch sparge with hotter water now and speed up draining the mash tun. I'll hit the fire to first runnings as well. What the hell.
 
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Did you start doing this because your were having problems? On a 5 gallon batch what volume of boiling water do end up dumping? I contemplated this but thought I didn't want to then heat up more water (second time) for the batch sparge???
 

dsaavedra

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The suggestions above are great. I need to look into doing a mash out when I batch sparge (really I just need to sparge with hotter water I guess) because I sometimes have this problem.

One thing I have found through playing with Brewers Friend is that if over shoot my target volume in the fermenter and then adjust my batch size to match in Brewers Friend it estimates a lower FG. For example, if I create a 5 gallon recipe and it estimates my FG to be 1.011 but I actually end up with 5.75 gallons in the fermenter, when I change my batch size to 5.75 the FG may drop to 1.009 (just an example - made up numbers). So if you are not nailing your volumes that may be something to consider. But it sounds to me like thermometer/mash out would be more likely culprits.
 

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I've never used Brewers friend but I'm thinking that the attenuation as a percentage is fixed per your mash temp. By increasing volume it predicts a lower starting gravity and lower final gravity because it's a percentage of starting gravity.
 

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Now I'm confused. Is attenuation a function of the duration of temperature change after proper mash out? For example: identical mash outs appear in two different kettles. One is abandoned for 30 minutes after BK is filled, then heated to boil. The other is heated as it enters and boil occurs coincident to last drop of mash-out.

This would cause different attenuation levels with all else being equal?
 

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Now I'm confused. Is attenuation a function of the duration of temperature change after proper mash out? For example: identical mash outs appear in two different kettles. One is abandoned for 30 minutes after BK is filled, then heated to boil. The other is heated as it enters and boil occurs coincident to last drop of mash-out.

This would cause different attenuation levels with all else being equal?
After a "complete" mash out, all of the amylase enzyme will have been denatured, so the sugar profile should not change with time. The attenuation due to mash and pre-boil parameters will be the same. Things could happen post boil that would affect the attenuation.

Brew on :mug:
 

D-Train

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Did you start doing this because your were having problems? On a 5 gallon batch what volume of boiling water do end up dumping? I contemplated this but thought I didn't want to then heat up more water (second time) for the batch sparge???
No problems, just like you I had higher attenuation than predicted and thinner beers without a mashout. I usually start with 1.25qt / lb. and end up with 1.8 qt. / lb. after mash out. Haven't tried this with a big beer yet and nearly maxed out my cooler on a recent IPA.
 

apshaffer

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I had issues with low FGs for a long time. My problem ended up being my hydrometer was reading 4 points low. It read 0.96 in distilled water. Check your hydrometer in distilled water. Could be that simple. My efficiency and my FG were higher than I was measuring them.

FYI, I have a similar system, and I have to mash out with near boiling water to bring the grain bed to 170.
 
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ssspargur

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apshaffer are you mashing out your first mash with boiling water? Or your batch sparge?
 

apshaffer

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I use my immersion chiller as a make-shift HERMS. I use my pump to recirculate my wort through the IC, which is in my boil kettle with water around 180. I recirc until the grain bed reaches about 170. I keep it there for 10 minutes or so, then drain my first runnings into a bucket. Then I batch sparge.

I only started mashing out this way after I tried to figure out why FGs were so low, but the main culprit ended up being my hydrometer was way off. My FGs are still a point or two low, but I was calculating them as 5-6 points low.

I do 10 gallon batches using a 10 gal round cooler for a mash tun. Most of the time, I don't have enough volume in the MT to add enough water to reach mash out temps. So I figured I would try the HERMS with the IC. I already had everything to do it. If you have a pump and and IC, try it out.
 
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