Over attenuation - I think i may be on to something. Diagnosis and solution?

[jldc]

I also had this same problem. FWIW I'm blaming it on not heating the first runnings. I've heated my first runnings right away and my FG's have gone from 1.006-1.009 up to 1.013-1.016 for average gravity beers. None of these beers are ready to drink yet, but they tasted pretty darned good when I kegged. I must say that I haven't really been able to tell much from tasting room-temp, flat, young beer. I've also raised my sparge temps some (I batch), but I figure the greatest quantity of sugars come out in the first runnings anyway, so that's where the money is.

 

[JuanMoore]

Uhm... How are runnings still converting? Runnings are the start of your wort, and are drained off of the grains.

Are you all saying that conversion keeps going within the runnings? and does not rely on the grain?? -
This is where I'm at in my process, and I really don't have a clear picture in my mind of concept. I'm just asking
I just imagined that conversion had to come from the Mash that is still in contact with the grain...

interesting point I think ??

What about those Aussies that "no chill" and store their wort? is all that delayed fermentation hitting 1.090's?? They are not chatting us all up drunk off their butts and yelling about it!!

What's happening in the mash is that enzymes are breaking down the starch in the grain into complex sugars, and then breaking the comlex sugars down into more and more simple sugars. These enzymes and sugars are all contained in the liquid of the mash, and the process keeps happening until either the temperature denatures the enzymes (above 168F), or the enzymes have broken the sugars down as far as they can. How far the enzymes can break the sugar chains down depends on the type of active enzymes, which depends on the mash temp. Higher mash temp = more unfermentable sugars and higher FG.

The aussie "no chill" method refers to not chilling after the boil, which has no effect on the mash profile since the enzymes are denatured (killed) during the boil.

 

[BuzzCraft]

yeast infection...thanks for updating. glad to hear you're getting it worked out.

 

[JuanMoore]

I often choose when to light the burner on my boil pot depending on how close my mash temps were. If they were a little low or right on, I start heating the first runnings immediately to lock in the mash profile. If they were a little high, I let the mash go a few extra minutes, and wait until all the runnings are in the pot before lighting to give the enzymes a chance to work a little more.

 

[Nugent]

Awesome, HBTers, just awesome. Very glad that I did this search.

Getting sick of summer session beers ending up at 1.002 and going up by 1-1.5 % ABV.

Cheers everyone!

 

[Catt22]

While I generally agree with most everything everyone has posted on this, IMO low mash temperature is most likely the cause. Determining what your average mash temperature actually is can be tricky. Sure, it's a must to have an accurate and well calibrated thermometer, but how you measure the temp and if the measurement is an accurate representation of the actual average mash temperature is another thing entirely. Frequently the grain bed will not be of a uniform temperature throughout. This is the main reason that I built a RIMS. My attenuation is usually right where I want it to be or very close now. It wasn't always that way, but usually the beers finished out on the high side, not too low. That problem has largely gone away, thank FSM.

 

[SamuraiSquirrel]

I also had this same problem. FWIW I'm blaming it on not heating the first runnings. I've heated my first runnings right away and my FG's have gone from 1.006-1.009 up to 1.013-1.016 for average gravity beers. None of these beers are ready to drink yet, but they tasted pretty darned good when I kegged. I must say that I haven't really been able to tell much from tasting room-temp, flat, young beer. I've also raised my sparge temps some (I batch), but I figure the greatest quantity of sugars come out in the first runnings anyway, so that's where the money is.

Yeah, mine is not ready to drink yet either. I'm excited to do a side by side of my pale ale that fermented down to 1.004 vs. my pale ale that stopped at 1.014.

I don't expect it to be one of those "wow" moments in home brewing but it should be satisfying none the less to have solved a problem in my beer that probably only I (or a judge or fellow beer nerd) would have noticed.

 

[CA-LT1]

thanks for the info, definitely helpful. I think I'll start using a mash out.

 

[Brocster]

I wanted to post an update on this thread for those interested.

I finally got around to brewing a batch since I posted this. I took the final gravity today on this new batch and it is right at 1.014! Normally I would have expected a lighter beer like this to ferment down to 1.006 or 1.004 as I described in previous posts.

The only thing I changed was that I added a mash out step. I also added each runnings to the kettle and began heating immediately after the round of runoff was complete (don't have things arranged where I can runoff into the kettle yet).

I kept everything else the same. O.G. was approximately the same (1.056) as my previous over attenuated beers.

I used US-05 as I did with my previous 5 or so batches.

Fermented in my basement at 68 degrees.

So I'm not sure if it was the mashout step or the heating of the runnings. I don't really think that both would be necessary. One or the other would probably do just fine. At least I know not to leave my runnings sitting in the bucket for a half hour to an hour unheated.

I know it's only 1 beer but I have not been able to keep a 1.05ish beer over 1.008 since I started brewing all grain so I am pumped about this.

Here is a way to look at this issue from another perspective, and involves NOT heating the runnings into the boil kettle.

One of my favorite styles to brew is a very traditional Kolsch. I think half the reason I like this style is that it can be very unforgiving in regards to hitting the style profile (dry with high attenuation, crisp, extremely pale, slight grain taste and low to no hop aroma and flavor components.)

When working to perfect my recipe and process, I once had to leave in the middle of my brew session to attend daddy-daughter function at my daughters school. I did this immidiately after batch sparging. I covered the BK and left it sit for over 2 hours.

I did a single batch sparge at 182 degrees, which brought my mash temp to 170. Thing is, when it is added to the BK, you know it drops when it hits the 1st runnings, my guess is that it stabalized at 157 or so.

I usually start my BK when I begin my lautering, but in this case, as I stated, I had to wait for over 2 hours. However, the final result was fantastic! My attenuation jumped to almost 88% (which is desired for this style), where before I was getting high 70's. There were two main differences in my process.

First, I did a rest at 141 for 45 minutes, then a rest at 158 for 45 minutes. Second, the brew kettle delay. I really think the majority of the difference came from the BK delay. Granted, I used a starter, aerated the heck out of everythin and so on, but that is one monster jump.

I am a believer in the fact that delaying the heating of the wort will result in a higher attenuation of the beer.

Hope this view helped out in someway. Great topic! I learned a lot by following this post.

Cheers!

 

[RedGlass]

Great thread, everyone!

For those who heat their first runnings right away: any concerns/experiences with caramelization due to heating such a small volume?

 

[Catt22]

Great thread, everyone!

For those who heat their first runnings right away: any concerns/experiences with caramelization due to heating such a small volume?

I have not had any problems at all, even with some of my light lagers. One of my regular recipes calls for first wort hopping and suggests keeping the run off at about 170F until it is finished, then to ramp up for the boil as usual. I never bring it to a boil until the sparge is finished, although with non FWH beers I go ahead and heat it towards boiling as I am sparging. No excessive caramelizing either way that I can detect. I say excessive as I am sure there is some darkening of the wort when boiling no matter what. I think some degree of caramelization is unavoidable and even desirable in many styles.

 

[maltMonkey]

Interesting....

I have never had a beer finish below 1.011, with 1.014-1.017 or so being pretty average for around a 5% beer. Everything I use is calibrated, and I have always mashed out (both with fly and batch sparging). I normally mash around 152°, but haven't really seen a huge difference between mashing at 149° and 158° as far as attenuation.

 

[bullinachinashop]

Great thread, everyone!

For those who heat their first runnings right away: any concerns/experiences with caramelization due to heating such a small volume?

You only have to raise the temp to above 168 and if you do that in a mash out, you won't have to worry about starting early.

Bull

 

[FreddieK]

This thread is fantastic! I have had the same problems with my AG beers for quite some time and I can't wait to see if adding a mash out helps my cause.

Thanks for all the great info HBTers!

 

[FreddieK]

This thread is fantastic! I have had the same problems with my AG beers for quite some time and I can't wait to see if adding a mash out helps my cause.

Thanks for all the great info HBTers!