Oddity with efficiency in my last batch

[jimyoung]

Hi all - I had a mistake in my last batch and I missed my target OG by quite a bit. Initially I thought it was due to my mistake, but beersmith seems to think otherwise. Thoughts?

The mistake: I added a zero in my recipe order to my LHBS (COVID, they measure and mill...) and got 58g instead of 580g of one of my grains.

Recipe:
- 4.11kg 2 row pils (german, 2.0 SRM)
- 610g Candi Sugar clear (0.5 SRM)
- 58g Carared (22SRM) (*** was supposed to be 580g)
- Wyeast #3787 (3L starter, decanted)
- water additions to bring the mash Ph to 5.3 as per bru'n water
batch size": 14L


I mashed at 69.4c, BIAB, about 90 minutes (I check gravity every 10 minutes and stop when it stops changing).

Beer smith says I should expect: (**All with the corrected, lower grain bill, not the original)
pre-boil 1.061 (I got 1.05)
post boil OG (before yeast starter) 1.085 (I got 1.064)

- My mash efficiency is set to 78%, and until now, my numbers are bang on.
- I am measuring using a refractometer. I recently did a thorough re-calibration, and it's a 1:1 match with my hydrometer.
- I measure the wort always at room temp

I just bottled the beer, and it came out as 1.019FG which was a little high. nothing I did could make it come down so I bottled.

So, I don't have much experience with recipe creation, but something seems fishy for me here. This seems like a huge miss, and that 500g missing grain doesn't seem to explain it. Thoughts?

 

[VikeMan]

Did you weigh the grains after you got them? And was the crush the same as on your previous batches?

 

[jimyoung]

I didn't weigh the grain, and I always ask for double crush (BIAB...). It looked normal. I guess I should have weighed them. I really trust my store, but anyone can make a mistake.

It's supposed to be a tripel, but of course it's a lot weaker. When bottling it tasted great, so maybe I'll make the /exact/ same beer again to see if I get the same results.

 

[Holden Caulfield]

What are your water volumes?
Preboil?
By batch size, do you mean what went into the fermenter, or what is packaged?

 

[jimyoung]

Ah thanks for catching that. Batch size of 14L is /intended/ packaged, what's plugged into beer smith.

My actual volumes were:
pre-boil 22.2L
15.3L into the fermenter

Some of the discrepancy (14-15.3) comes from the fact that I don't leave any trub in the kettle any more and dump it all in. So, my FG target shouldn't be impacted by this.

 

[Holden Caulfield]

A couple other clarifications to see if your points add up. If they do, then the issue can be pinpointed to measurement, or points extracted. If measurement, you are flying blind. If points extracted, it is either efficiency or the amount of grain not measured correctly.

When were the sugars added - towards the end of the boil, or before you took the preboil gravity?
Is your post boil volume before or after chilling?

 

[jimyoung]

Thanks for the troubleshooting ideas.
- pre-boil gravity was /before/ sugar added. My pre-boil target was excluding the sugar. My recipe has suger as a boil addition (next to the hops).
- I added the sugar beginning of boil, after pre-boil measurement
- I measured post-boil volume at 19c, after chilling.

 

[Holden Caulfield]

Math time:

Mash points = 50*5.86 gallons (22.2L) = 293 (actually 286 if volume measured at room temp)
Sugar addition = 1.34 lbs * 45 points = 60
Total points that went into the kettle = 353

Post boil points=64*4.04 (15.3l) = 258

There is a measurement error as the points should be the same. If you in fact obtained 293 points from this grain bill, that would be close to your 78% efficiency.

If you had 353 points post boil and ended up with 15.3l, your OG would be 1.087.

You may or may not have had a problem and may be chasing windmills.

Either way, you will end up with tasty beer.

 

[jimyoung]

Hey thanks, you know, I never did figure out the math approach. Now that you've spelled it out, I can see how easy it is.

The 22.2L number was actually original water, not pre-boil. I should measure after pulling the grain (and temperature adjust that volume) before boil, to help understand what is happening.

So yeah, since I take my mash measurement every 10 minutes, I'm pretty confident in that one unless the refractometer was way off the whole way (I calibrate with my tap water used in the beer).

I did measure my 22.2L at room temp. so that's 1.050 x 5.86 gal (US) = 293 points?
- post-boil volume at 4.04 should give me then 1.072 x 4.04 gal = ~293 without considering all that sugar I put in! I made the invert sugar myself, so the density of that sugar is suspect, but it's certainly not negative, and would be close.

Beersmith has my sugar at 1.036 potential SG. So I assume that 36pts per lb/gal, so that would give me 610g = 1.34lbs x 36 = 48 pts

So I should have in the ballpark of 341 points, which at the final 4.04gal should be 1.084? OK!!!!

So I'm liable to believe that I must have messed up my OG measurement.

I'm going to keep working through this.
Let's say that Beersmith's pre-boil gravity target of 1.062 assumed /with/ sugar.
so my 341 points / 5.86 gal is 1.058, which is a lot closer to 1.062.

Aha! I'm enjoying this.
So, then if my OG was more like 1.084, then I can re-calculate my adjusted FG (since I use a refractometer), and my FG comes out to
1.008 (1.009 target, which gives me 9.85% alc.

Now all I need is the real scientific test. I need to drink a bottle and determine if it == 2 beer. Or drink 2 and see if it == 4 beer

Thanks so much!

 

[bracconiere]

i believe if you have a hydro && refracto, there's a calc to put it to an OG and ABV after it's done fermenting.

 

[jimyoung]

yeah. I've always used Refractometer Calculator - Brewer's Friend . Every few years I start doubting myself and check my refractometer against my hydrometer, with carefully controlled samples / temps. They always give a 1:1 reading, so I don't use a correciton.

 

[bracconiere]

what i meant is you can take a hydro reading of the finsished beer, and a refractometer reading. and then use them both in combination to tell how much ABV you have, and thus what the OG was. let me find it. well, something like this.

https://www.homebrewtalk.com/thread...abv-with-hydrometer-and-refractometer.354260/

 

[jimyoung]

Oh I see, that's cool. Maybe I'll try that after a few weeks of bottle conditioning

 

[Holden Caulfield]

Now that you've spelled it out, I can see how easy it is.

Yes, it is very easy and the first step in trouble shooting what went wrong. It is also a very powerful way adjust your points to hit your target gravity. All you need to do is determine how many points you are under or over before boiling, and if over just pour of the volume of wort that contain the extra points. For example if 10 points over your target and your preboil gravity is 1.052, then pour off 10/52ths of a gallon of wort. If under just add DME using the same methodology. For example, if 10 points under and DME has 45 10 points per pound, then just add 10/45ths of a pound

The 22.2L number was actually original water, not pre-boil. I should measure after pulling the grain (and temperature adjust that volume) before boil, to help understand what is happening

Yes, preboil volume is what ends up in the kettle after lautering. If BIAB, then after removing the spent grains.

I made the invert sugar myself, so the density of that sugar is suspect, but it's certainly not negative, and would be close.

I believe what you made was candi-syrup, not sugar so the water in it will reduce the points per pound. Sugars are closer to 45 points, while candi-syrups are 32 points per pound. Since yours was homemade 36 will probably get you in the ball park.

The 22.2L number was actually original water, not pre-boil.

You can estimate your preboil volume by subtracting an estimate for your grain absorption. I use .135 gallons per pound which equals 1.22. gallons. If you subtract this from the 5.86-1.22 you get 4.63 gallons * 50 = 231 points. Adding the 48 sugar points you get 279 points into the fermenter. Which means your OG would be 279/4.04 = 1.069

Aha! I'm enjoying this

, you are on track to being able to hit your target OG everytime.

 

[jimyoung]

I'm going to have to re-make this brew and take better measurements!

And you're right, it's syrup I used, not sugar, sorry for the confusion. It's not /runny/ but it's not super thick. I wanted to stop it before it started to darken