Strange SG Issue

[Ryat66]

Hi all! Long-time lurker, first time poster.

I just brewed CYBI's Mirror Pond clone today. I scaled it from their 6 gallon batch at 70% to my preferred 5.5 gallon batch at 72% using BeerSmith. Process wise, I was pretty happy; initial mash-in was a tad warm at 4 degrees above my 149 target but I had it down to target in less than 5 minutes and it only lost 1 degree over the 75 minutes. Pre-boil gravity was exactly what BeerSmith estimated, 1.039 with 7.6 gallons (1.3 gal/hr boil-off) pulled for the 90 minute boil. After boiling and chilling I was at 5.4 gallons but measured the SG at 1.060, the recipe called for 1.054! This would make perfect sense if I got careless and boiled down too far, 5.4 gallons vs. 5.5 gallons is peanuts in my book...

I am somewhat afraid of what the end result might be here. I am expecting it to finish a little high but not overly high because of the lower mash temperature and a little more fermentable wort. I know it's just speculation but any ideas on what I might expect out of the end product?

Oh, here is something that came to mind: the sample was fairly littered with trub but could that make me appear to be 6 gravity points higher than anticipated? That seems unlikely but maybe I'm underestimating the trub's effect on the sample.

Anyway, here is the recipe in case anyone wants to see it. Most importantly, thanks in advance for any input on what might've happened here.

Recipe Specifications
--------------------------
Boil Size: 7.67 gal
Post Boil Volume: 5.72 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.50 gal
Estimated OG: 1.054 SG
Estimated Color: 10.6 SRM
Estimated IBU: 41.4 IBUs
Brewhouse Efficiency: 72.00 %
Est Mash Efficiency: 72.0 %
Boil Time: 90 Minutes

Ingredients:
------------
Amt Name Type # %/IBU
10 lbs 9.0 oz Pale Malt (2 Row) UK (3.0 SRM) Grain 1 91.4 %
12.9 oz Caramel/Crystal Malt - 80L (80.0 SRM) Grain 2 7.0 %
2.9 oz Cara-Pils/Dextrine (2.0 SRM) Grain 3 1.6 %
0.80 oz Cascade [6.90 %] - Boil 85.0 min Hop 4 24.7 IBUs
0.80 oz Cascade [6.90 %] - Boil 30.0 min Hop 5 12.6 IBUs
1.10 Items Whirlfloc Tablet (Boil 15.0 mins) Fining 6 -
0.50 tsp Yeast Nutrient (Boil 10.0 mins) Other 7 -
0.80 oz Cascade [6.90 %] - Boil 5.0 min Hop 8 4.1 IBUs
0.80 oz Cascade [6.90 %] - Boil 0.0 min Hop 9 0.0 IBUs
1.0 pkg English Ale (White Labs #WLP002) [35.49 Yeast 10 -
0.75 oz Cascade [6.90 %] - Dry Hop 5.0 Days Hop 11 0.0 IBUs


Mash Schedule: Single Infusion, Medium Body
Total Grain Weight: 11 lbs 8.8 oz
----------------------------
Name Description Step Temperat Step Time
Mash In Add 18.63 qt of water at 164.2 F 149.0 F 75 min
Mash Out Add 9.97 qt of water at 210.4 F 168.0 F 10 min

Sparge: Fly sparge with 2.97 gal water at 168.0 F

 

[huckbof]

try filtering and re-measuring the sample if you still have it
or if you haven't tossed the dregs put them in a container
and cold crash it to clarify the sample and remeasure

what mash efficiency do you usually get, 72?

 

[Ryat66]

Unfortunately, I was kinda ticked and never thought to keep either. In fact, I didn't even consider the trub idea until a few hours later. Live and learn...

Yep, 72 is my number.

 

[huckbof]

well 1.039 is low efficiency for you then, you should have been ~1.041
I'd guess that your pre-boil sample measurement was low and the trub in your OG caused it to be high and that might account for the difference

 

[Gavin C]

I would discount the trub in the sample theory behind the high SG. You would have had to make a near deliberate attempt to remove tons of trub for a sample for it to have any effect. It settles to the bottom pretty quick and has negligible impact on readings.

Hydrometer sample with trub settled

There are few possibilities to consider

True error (higher than planned efficiency for correct weight of grain)
Measurement error


If it is a true error it implies your measures of pre boil and post boil volume and gravity are correct in addition to correct grain bill weight. Conclusion. Your eficiency is improved and you will need to adjust your equipment profile.

If it is a measurement error this could be one or more items.
Are your grain weights correct?
How do you measure the volume?
Are you cooling the hydrometer samples to the calibration temperature of the hydrometer.
If you can eliminate measurement errors and are happy with your data then I would conclude you got a higher mash and BH efficiency.

 

[Ryat66]

well 1.039 is low efficiency for you then, you should have been ~1.041
I'd guess that your pre-boil sample measurement was low and the trub in your OG caused it to be high and that might account for the difference

Your input and a good night's sleep has shed some light on this.

I went back through my notes (thankfully I take notes) and I figured everything out but I wouldn't have done that unless you brought up the point about my pre-boil gravity being low, that just didn't make sense if SG was then high. It proved to an excellent tip and maybe the defining one here.

Anyway, I should know better but I have been relying on the temperature adjustment scale on the hydrometer. I now know this is a huge mistake because my temperature (125F) adjusted pre-boil gravity was in fact high, 1.042. I plugged all of this into BeerSmith's tools this morning and I now know exactly what happened. Here are the screen shots:

Had I done the proper calibration on the hydrometer when taking my pre-boil gravity, I would've noticed this better than anticipated efficiency and adjusted on the fly.

However, I still see that my efficiency was better than anticipated on this batch and will need to scale for the next time I try it. So, I will need to set this recipe to 80% and rescale to 72%. Correct?

 

[Gavin C]

Glad to see you figured things out.

 

[Ryat66]

If it is a measurement error this could be one or more items.
Are your grain weights correct?
How do you measure the volume?
Are you cooling the hydrometer samples to the calibration temperature of the hydrometer.
If you can eliminate measurement errors and are happy with your data then I would conclude you got a higher mash and BH efficiency.

Thanks for taking your time with me.

-I checked the slip from the LHBS and the weights are spot on. They actually use a scale system where you input the bin number, weigh the grain, hit done and it prints the weight on the slip.
-I measure and mark all of my vessels upon purchase by measuring with an 8 cup (1/2 gallon) measuring cup. My stir paddle is marked specifically for my kettle with 1/2 gallon increments. My carboy has measured out Sharpie lines on the outside. I don't use buckets.
-I think this is the issue which I described in my response to 'huckbof'. See above.
-I think I concluded I received higher than expected mash and BH efficiency. I just hope attenuation is somewhat reasonable. I checked the pitching calculator and it appears that I under-pitched by a total of 6 billion cells for the 5 gallons into the fermenter. I'm not going to sweat that just yet but I am using WLP002 so I could end up with a rather syrupy pale ale with grapefruit and floral undertones from the Cascade. I'm not expecting much but who knows maybe I'll be surprised, it certainly won't be a Mirror Pond clone though approaching 6% ABV, that much I'm sure of.

I use a blow-off because I don't have enough height in my chamber for an airlock and when I checked it this morning it was pushing a gurgle every 3-4 seconds and the yeast was swirling around like a mofo. Fingers crossed I get something decent.

So, I asked this in my response to 'huckbof' but I'll ask you too. Assuming I want to try this in the future, how do I change the recipe in BeerSmith? So, I set efficiency on the recipe to 80% which changed the estimated OG to 1.060 as I would've expected. However, what's next? Adjust the gravity back down to 1.054 and scale to 72%? I was playing around with it and just couldn't make sense of it.

 

[Gavin C]

With more and more brews at similar SG's you will zero in on an efficiency. I would up your BH estimate to 75% into the FV for next batch and formulate the recipe accordingly. If you are still a bit hugh (eg 80) you could up it to that. What I would not do right away is adjust the BH efficiency to 80 and work to that as you may end up short on your OG. Perhaps not but my approach is incremental.

I use 77% but will hit higher depending on the grain bill and am usually aiming for middle ground in terms of style guidelines (I like to brew to style). If I end up a hair over or under it is not a concern, the beer will still be what I was aiming for.

Sounds like you are extremely meticulous with your measures of volume and weight. I am a fan of this approach.

Hope this helps

 

[Ryat66]

With more and more brews at similar SG's you will zero in on an efficiency. I would up your BH estimate to 75% into the FV for next batch and formulate the recipe accordingly. If you are still a bit hugh (eg 80) you could up it to that. What I would not do right away is adjust the BH efficiency to 80 and work to that as you may end up short on your OG. Perhaps not but my approach is incremental.

I use 77% but will hit higher depending on the grain bill and am usually aiming for middle ground in terms of style guidelines (I like to brew to style). If I end up a hair over or under it is not a concern, the beer will still be what I was aiming for.

Sounds like you are extremely meticulous with your measures of volume and weight. I am a fan of this approach.

Hope this helps

Extremely helpful. Thank you!

 

[huckbof]

yeah, I thought your OG was low b/c your process looks good and your calc %eff was too low. I was sort of surprised that you'd aim for such a low efficiency, most of us are trying to raise it into the 80's.

If I were you I wouldn't trust any temp adjustments of a hydrometer above say 75F.

Be more meticulous and use a small copper or aluminum container to cool those samples in a cold water bath in the sink in only a few minutes.

You know how you use an 8 cup measure to graduate your equipment...well every time you fill the 8 cup container there is a measurement error so as you fill it up the relative measurement errors add up.

A better way is to use weight (which usually involves higher precision and accuracy) and convert to volume 8.34 lbs/gal, that way there is only one measurement error.

under-pitched by a total of 6 billion cells

I don't think 6B is very much, well within the error of estimation

So, I will need to set this recipe to 80% and rescale to 72%. Correct?

if you want the ABV back down, try this...
when making your priming solution use more water to achieve the ABV you want. use this calculation

added water = 5.4*60/54 - 5.4 = 0.6 gals

5.4 is your current volume
60 are the points for your OG
54 are the points you wanted for your OG

so make your priming solution in ~2 quarts of water, just make sure it boils at least 15 mins

you could have added the extra water needed during or near the end of the boil by boiling it on your stove

next time adjust your target efficiency and if need be adjust boil rate or water add on the fly,...but cool down those hydrometer samples

 

[Ryat66]

yeah, I thought your OG was low b/c your process looks good and your calc %eff was too low. I was sort of surprised that you'd aim for such a low efficiency, most of us are trying to raise it into the 80's.

If I were you I wouldn't trust any temp adjustments of a hydrometer above say 75F.

Be more meticulous and use a small copper or aluminum container to cool those samples in a cold water bath in the sink in only a few minutes.

You know how you use an 8 cup measure to graduate your equipment...well every time you fill the 8 cup container there is a measurement error so as you fill it up the relative measurement errors add up.

A better way is to use weight (which usually involves higher precision and accuracy) and convert to volume 8.34 lbs/gal, that way there is only one measurement error.



I don't think 6B is very much, well within the error of estimation



if you want the ABV back down, try this...
when making your priming solution use more water to achieve the ABV you want. use this calculation

added water = 5.4*60/54 - 5.4 = 0.6 gals

5.4 is your current volume
60 are the points for your OG
54 are the points you wanted for your OG

so make your priming solution in ~2 quarts of water, just make sure it boils at least 15 mins

you could have added the extra water needed during or near the end of the boil by boiling it on your stove

next time adjust your target efficiency and if need be adjust boil rate or water add on the fly,...but cool down those hydrometer samples

I never thought about weighing water but that completely makes sense. I will actually go back through and do this over the next few weeks. I have a second paddle that I haven't even cracked the plastic on so that works out perfectly.

Also, I will definitely measure the samples at or below the temperature you suggested.

One question on diluting the beer at bottling. Will that extra ~1/2 gallon affect flavor much or is that not worth worrying about? I will be sure to adjust on the fly next time.

Again, thank you for being so generous with your time. I really appreciate the engaging aspect of this conversation because I am meticulous about almost everything in my life, brewing is no exception. However, there are many variables in brewing and as you can see I'm still learning. Trust, but verify. As much as I enjoyed the camaraderie of brewing with friends, I grew tired of the "that's good enough" mentality; I grew tired of investing time and money in a mediocre end product. Case in point, I was chatting with one of my buddies yesterday and told him about the high starting gravity and he said "that's great, you'll end up with a higher ABV!" Ummmm...that's not what I'm trying to accomplish here... Anyway, enough of that.

I can actually tell you why I was targeting that percentage and once again, you've triggered an ah-ha moment. I have been using a friend's well water up until this point and knowing this area I suspect it was somewhat hard but more than likely, had a higher RA. When I first started AG that was a stab in the dark percentage, something simply to target as a starting point. More often than not, we hit our numbers so we stuck with it.

Fast forward to my brew session this past Sunday and for the first time ever I made my own water from spring water. However, it wasn't just a blind stab, a few months ago I found a local family owned bottler with a local spring and they gave me quarterly reports for the previous 6 quarters. The water has been very consistent but I still found the average reading over those 6 quarters, for each metric and plugged those numbers into Bru'n Water. From there I adjusted to the water profile suggested by Jamil for this brew. Key thing: for once my pH was in range (5.3) and I NEVER thought that it would unlock efficiency but apparently it did! I can see there's some additional reading in store.

Bottom line: now that I'm brewing on my own and developing water profiles, brewing by myself, etcetera, there will probably be a small shakedown period that I will need to go through. I just need to keep honing in and make my process as repeatable as humanly possible.

Again, thank you for giving me time out of your day.

 

[Gavin C]

I wouldn't dilute your beer with water post fermentation. I slightly higher ABV is not a big deal. Just refine the process for future brews. Adding water will reduce ABV.

It will also reduce, flavor, body, mouthfeel and color. Too much to give up in my view. But it is just that. A view point.

Great advice on the volume calculations though.

 

[huckbof]

yes. indeed reducing ABV was the point in order to hit the clone.

Conversely, not diluting it will give it too much ABV, mouthfeel, etc etc for the beer that he is trying to clone. What would be the point of cloning? If he sat down with his beer and the actual beer he is cloning and did side by side taste tests and concludes that he was off because it tasted slightly different, had more mouthfeel, too much head, more body etc. etc. Might as well try and hit the clone.

Now if it was me I would have just went with it because I don't see the point in clones.

This link talks about diluting beer with water, but it must be boiled to get the O2 out of it. I guess it is common practice.

https://www.homebrewtalk.com/f128/diluting-beer-after-fermentation-310265/

 

[Ryat66]

Now if it was me I would have just went with it because I don't see the point in clones.

Actually, I agree. I think a recipe to clone, is a recipe to fail. I attempted it because it is something identifiable and a starting spot for my first pale ale.

I'm on the fence with diluting it now. I wish I had just diluted the wort on Sunday. Oh well, I'll think about it.

 

[huckbof]

If you really like the beer...then do it, at least you will learn something from it and you also get 5 more beers

 

[Ryat66]

A quick update on this...

The bulk of fermentation has wound down and since WLP002 is notorious for under-attenuating I thought I'd grab a gravity sample this morning before I turn the heat up a few degrees for a small diacetyl rest which is recommended by White Labs for this strain. The gravity (temperature adjusted of course ) is sitting at 1.016 so I've missed the d-rest window but a swig of the sample really doesn't reveal any buttery or greasy undertones. Additionally, I am in no hurry to pull it from the cake, I'll just let it go and clean up over the next week or so. The sample was quite nice and I'm kind of hoping is doesn't attenuate much more if any because I liked it.