OG missed again on my second DIPA using Brewersfriend

[DonY]

I was 9 points short of my OG in the fermentor even though my pre-boil SG was spot on (after diluting to bring OG down due to an overly efficient mash and drawing excess wort off to hit my pre-boil volume). My post boil volume was spot on too. My trub loss in kettle post boil was 0.5 gallons less than expected which meant I left a lot of beer behind relative to my 2.6G target volume into fermentor. This of course negatively impacted my brewhouse efficiency.

When taking my post boil gravity reading I ensured the wort was well stirred and I took several reading with my calibrated refractometer. All readings were the same.

My target in the recipe editor was set to Kettle.

Here were my efficiencies for this brew session:

Conversion: 87%
Pre-boil: 71%
Ending Kettle: 61%
Brew House: 36% :-(.

Not sure what I should be tweaking in my equipment profile and recipes to prevent coming so short on my OG when doing DIPAs while over achieving on mash efficiencies and pre boil eff. Is it possible that Brewsfriend doesn't account for the sugars absorbed by the hops when brewing a heavily hopped beer? I did squeeze my hop bags.

This is really getting frustrating.

 

[Ozarks Mountain Brewery]

if you could post the recipe that would be helpful too

 

[DonY]

Recipe in attached screen shot.

This is the fourth time I've brewed this recipe but first time using Brewersfriend. I went back and looked at my last 3 batches which were done using biabrewer.info Biabacus spreadsheet which predicted a pre boil gravity of 1.058. Ironically my initial pre boil gravity with this batch was 1.056 that I diluted down to match Brewersfriend prediction of 1.048. If I'd continued without dilution I bet I would have hit my target OG. I also extended my mash time to 75min and did a 170F mash out for 10min because at 60min my gravity was not at target yet.

You'll also see my actual post boil volume was 0.3G higher than target but my pre boil volume was also 0.3G above target so pre boil to post boil ratio is the same as if I'd hit my volume targets on both ends. I should be able to fix that by adjusting my grain absorption amount in my equipment profile.

Thanks for reviewing.

 

[Ozarks Mountain Brewery]

one thing, did you get 4 gallons after the boil without adding anything (water) and yes you can't dilute and get a true reading.
First bib is a rather broad type of brewing and you can do it a number of ways and get different results.. 5 people can brew that recipe and come out with different stats, not saying you did anything wrong at all but it will not be an exact science until you perfect your process, it might take years even I still fiddle with mine.

It might even be that we need to come up with a better way for you to tell the site how you intend to brew that bib. From my point of view, if you don't start with all the water you need ahead and never change anything until the end, its not really going to be easy to hit numbers, so its almost brewed like a partial mash.

when I first started out using brew in a bag I had a 10 gallon pot and had issues with the correct amount of water so I had to step up to a 15 gallon pot just to brew 5 gallon batches and after starting out brewing a lower efficiency than I wanted I then invested in a pump to do a continuous fly sparge. only then I was able to get a good efficiency. I was able sew a ring into my bag and use a winch to pull the bag up so I could pour sparge water while it was up in the air. Then I stopped using the bib settings and started all my recipes with all grain. only then was I able to hit my numbers right on. So if your a couple of points off I wouldn't worry eventually you'll work it out

 

[DonY]

I started with a full volume of water at mash (6.5G, no hold back). As I look back over my brew day notes my pre and post boil volume deltas were off from the recipe editors pre/post boil volume deltas by roughly 0.3G with all the dilution and siphoning going on to get to the pre boil target SG. I need to pay closer attention to these volumes real time. Unfortunately extending the boil time to boil off more volume would have boiled off more of the late hop additions aroma impacting that while increasing IBUs. Trade offs abound :/. I also should have taken a gravity reading post boil but before the hop stand so I could measure the impact the big hop stand had on my OG into the fermentor. It also would have provided me a chance to add DME (of course at the expense of IBUs) to bring the OG up. A good enhancement to Brewersfriend brew session steps would be to allow inserting steps for various volume and gravity measurements at key process points especially near end of boil when a lot is happening where there are 20min, 10min, 5min, knock out activities to be performed.

 

[DonY]

...First bib is a rather broad type of brewing and you can do it a number of ways and get different results...

I know of only two methods of BIAB, BIAB (full volume mash) and Maxi-BIAB (mash water held back and used as sparge water when full mash volume is to big for your kettle). What other BIAB methods are you aware of?

As for taking years to dial in ones process, with regards to hitting target volumes and gravities for similar beer style brewed during similar times of the year (if brewing outside where boil off rates vary) I would respectfully disagree. Yes, it could take many batches of the same recipe to fine tune a recipe to ones liking. After one batch you have a good idea of boil off rate for a given intensity of boil. You know your grain absorption rate for your mash. You know your kettle to fermentor volume loss due to trub and break material. All probably within 10%.

Adjusting ones equipment profile using previous brew's measurements for say DIPA style should get me very close on my targets for next brew of that style using same equipment. The only measurement on a heavily hopped beer I can't accurately make is hop absorption rate since I squeeze my bags. Perhaps that's what's throwing my target OG off.

 

[Ozarks Mountain Brewery]

just to clarify on bib, you can just pull the bag up and drain, you can dunk it in and out, you can run water over the top to rinse while up in the air, you can hoist and fly sparge through the whole mash, you can pull the bag out, drain then set it in a bucket and soak with fresh water, drain again and repeat ....all will produce different results

yes heavenly hopped beer absorbs more water than you think and how you hop will change that, with a bag or not or through trub and hop filters, hop backs. I have beers with more than 6 ounces of hops including dry hopping and I lose 2 gallons before the beer reaches my kegs, I adjust my recipe to compensate. if I take those same settings and brew a mild it throws everything off. so in the end all I care about with heavily hopped beers are the beginning "wort" gravity before fermentation and ending after fermentation, all other readings can be misleading.

but if your brewing a mild with only 1 ounce in the whole beer you can dial in exact readings

 

[Ozarks Mountain Brewery]

one of the issues with bib in general is that you don't sparge. Sparging plays a huge roll in hitting the efficiency of the beer, and the original gravity. If you copy a recipe that was created with an advanced all grain set up and brew it with brew in a bag, you might be disappointed because that brewer had a 80 to 90% efficiency and the reason why is and advance sparging system. that system can get more sugar out of the grain. since you don't sparge in bib you can just add more grain to compensate and it might work, good luck

 

[Head First]

Don Y you can't lose sugar by boiling down wort. Somewhere your measurements are throwing your efficiency readings off. Also if you are losing 1/3 of your ppg's between ending kettle and brewhouse efficiency something is wrong there too. I struggled with this efficiency calculation on this software myself until discussion with Larry Brewer and found several small changes in the way I measured volumes was the main culprit. Just keep in mind you can't lose sugars like that. They don't just disappear. Pay attention to the water calculator and stick with the same volumes you start with. If you are getting better conversion from your grain then you will get a higher preboil. But if you have added more water the OG will not be correct from the software. Keep working at it, the answer will come to you.

 

[DonY]

Thanks for the feedback .

This wasn't the first time I'd brewed this recipe with my equipment and BIAB process, so, I had a good idea what my trub losses and efficiency into kettle should be when I laid this into Brewersfriend recipe editor and set up my equipment profile. The only new variable for me was Brewersfriend's recipe editor. The next time I brew this beer I've already reduced the mash grain absorption based on actuals form this brew session (there was less absorption resulting in 0.5G excess wort). I'm also lowering my kettle efficiency from 65% to 61% based on Brewersfriend's brew session's actuals and it's kettle efficiency calculation. Is there anything else I should be measuring and adjusting accordingly in Brewersfriend?

I just reviewed the "How efficiency is calculated" FAQ again and picked up the mention of the ending kettle efficiency corner case where raw late edition sugars/extracts do not go into this calculation. This seems odd since my actual gravity measurement does include the late edition sugars. Is the raw sugar gravity contribution subtracted from both the predicted and actual SG? I hope so otherwise there's an "apples and oranges" comparison taking place.

A suggestion for the ending kettle efficiency FAQ and that's to recommend taking a gravity and volume measurement at knockout so one has the chance to correct missed OGs and volume before cooling. After cooling you have to heat the kettle back up to a boil, make corrections and then cool again. Current FAQ says take measurements after cooling.

As for taking volume measurements at knockout, it would be a nice enhancement to the equipment profile to have an entry for volume displaced by immersion chiller and offer an option in brew log entry for end of boil volume to subtract your immersion chiller volume. Today I have to don insulted gloves, lift my chiller out and attempt to read my kettle markings through the steam when I remember to take that measurement.

 

[Head First]

Are you doing temperature corrections for your volumes?
If your preboil OG was higher are you getting better efficiency not worse?
Did the added water to correct preboil OG throw the calculations off?
Just ideas.

 

[DonY]

Are you doing temperature corrections for your volumes?
If your preboil OG was higher are you getting better efficiency not worse?
Did the added water to correct preboil OG throw the calculations off?
Just ideas.

Good catch on temp correction on volume. I went back to brew log entries and made those corrections which changed volume by 0.1G and in turn lowered my end of boil efficiency by 1%. As for adding dilution water I siphoned off excess wort to bring down my pre boil volume down near what Brewersfriend predicted.

I still think the amount of hops used during the boil and in my hop stand absorbed a significant amount of the sugar even after squeezing the hop bags bringing my OG lower than what Brewersfriend predicted. It's not clear if Brewersfriend Recipe editor accounts for that absorption.

Ironically the BIAB spreadsheet I've used for my 3 previous batches of this recipe predicted a pre boil SG 10 points higher than BF's for the same grain bill which matched my actual pre boil SG I measured and subsequently diluted to match BF's prediction. I suspect if I hadn't diluted I would have nailed the SG.

 

[Head First]

The software is only as accurate as the info input into it. I understand where you are at with this. When I began using Brewers Friend I was excited to find out my efficiency's without massive calculations only to be dismayed by results all over the board. When I rechecked all my volumes and temps and with help from someone pointing out the way's to look for corrections in my readings, things started to come around. For example from what I understand refractometers which I choose not to use, are not exact as well as hydrometers. I have had several different hydrometers and they all read off .001 or .002 except for "the one". That's why there is a place in the software to show this correction. It sounds like you are on the right track. Sometimes the simplest answers are the hardest to find.