Struggling with OGs, FGs, and ABVs
- Thread starter Mike at Bay
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Yup, that’s a problem. I bet if you topped it less it’d be ok.
Indeed, it’ll still be ok.
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since you won't be brewing for a bit, now would be a great time to test your boil off rate! All you need is the kettle, water, heat and a timer. Once you get a boil off value, you can better calculate how much you need for the boil off so you better make your numbers. You need this for BIAB anyway.
once you cover all the variables, you can get more consistent numbers closer to the target.
Thanks all. I have all the grains for my next batch (Sierra Nevada PA Clone). Also, purchase some water additions and refractometer. I will be brewing in a bag with a recipe from BrewFather. Will let you know in early 2026 how all of this great advice ended up in a better beer.
All....been a bit since the original post. Brewed my first BIAB all grain recipe yesterday a Sierra Nevada Clone. Used many of techniques as suggested in this thread. Thanks!! Water levels were on...ended the boil with 5.5 g just as expected. Pre Boil gravity as measured with hydrometer was right on at 1.043. Post boil volume looks low as measured with my Tilt and standard hydrometer at 72 degrees...I am at 10.48 vs expected 10.54. I had to use slightly different malts than the suggested brands but I assume since they were measured properly that should be no issue. Also, all Cascade hops. Missed the step of checking the gravity prior to flame out and did not add DME which would have helped for sure. So beer is in the fermenter on dry yeast (ale 05).
I will attempt a Blonde Ale this weekend and run the process again....see where we land
I will attempt a Blonde Ale this weekend and run the process again....see where we land
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Also consider a couple things. 1) Tilt are not super accurate
2) tilt are effected by temp. So wait till your temp stabilizes before relying on a measurement
Thanks Minbari. Yep. A quick update...this morning, moments after pitching, I took a sample from my conical fermentor spigot. Put in the fridge for a bit and went back 15 mins later.....the heavy hop debris sank to bottom......took a dropper from the top of clear beer and put it on the refractometer and viola it is near 1.053!!!! Yippee!! This clone has 2.2 oz of cascade at 30 mins and another 2.2 oz at flame out so the bottom of the sample is pea soup. 
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You don't mention what your pre-boil volume was but you'd need to start at about 7 gallons of 1.043 to get to 1.054. Six quarts is a little high for boil off rate but to get to 1.048 you'd have to be at 2 quarts boil off, which is low. Is your hydrometer calibrated to 72 degrees? They're typically 60 degrees but that would only make a .001 difference.
Not to be a downer but your refractometer isn't accurate enough to rely on due to wort color. A hydrometer reading is the only thing you can really count on. Assuming you know your pre-boil volume and that your post boil volume measurement is accurate and assuming that you cooled your sample to proper calibration temp, that pre-boil reading is enough to accurately extrapolate your OG - more accurate than a refractometer reading.
Not to be a downer but your refractometer isn't accurate enough to rely on due to wort color. A hydrometer reading is the only thing you can really count on. Assuming you know your pre-boil volume and that your post boil volume measurement is accurate and assuming that you cooled your sample to proper calibration temp, that pre-boil reading is enough to accurately extrapolate your OG - more accurate than a refractometer reading.
Thanks JA. My Pre Boil was 1.043 and I had about 7 gals. probably a little more. Hydro is calibrated to 60. No worries about the refractometer reading....I am chilling the sample now to get it to 60 and will take another hydro reading.....lots of hops in the sample. My tilt in the fermentor still shows 1.048 at 72 degrees. I am going to make an assumption that my measurements are off somewhere.
To get the water in the kettle for the brew I used a measured one gallon pitcher. the recipe from Brewfather indicated 8.36 gals. However, to determine my brewhouse boil off prior to brew day I boiled 5 gals at a rolling boil which seemed to get me to 3.5 gals of water. I may have an error there. I am going to try my boil off process again to see where I went wrong.
To get the water in the kettle for the brew I used a measured one gallon pitcher. the recipe from Brewfather indicated 8.36 gals. However, to determine my brewhouse boil off prior to brew day I boiled 5 gals at a rolling boil which seemed to get me to 3.5 gals of water. I may have an error there. I am going to try my boil off process again to see where I went wrong.
Chilled the sample to 60ish and took another reading on the sample with Hydrometer. I am at 1.51ish
Thanks all.
Thanks all.
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My 2 Tilts read identical to the old school hydrometer - when the hydrometer is at its calibrated temperature. It does take the tilt temperature reading time to stabilize, especially if you just gave it a hot water/star san bath before dropping in the chilled wort.
I knew only superficial data about the refractometer -in context-, and knew it was not as precise but this article was pretty helpful: https://byo.com/articles/refractometer/
so you have a .003 variance; about the variance from my refractometer to my tilts and hydrometer. Did you verify the tilt calibration?
https://tilthydrometer.com/blogs/news/multi-point-calibration-with-the-tilt-2-app
I believe I did.....meaning if I did it right, yes.
Based on this description I did not do it right.I believe I did.....meaning if I did it right, yes.
. I will use it to determine when fermentation stops only this time around and recalibrate following this brew. again, thanks all.. I am slowly figuring it out.- Joined
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In a bigger kettle, starting with 8 gallons of water, should net about 7 after you pull the bag. Squeeze the shit out of the bag. You shouldn't lose much more than a gallon in Florida after an hour boil. That leaves 6, and you will end up with 5 to 5.5 in the fermenter. Adjust your efficiency setting in the software. regular, straight, no sparge, one vessel BIAB will probably be in the low 60s. Others get better. I don't. Start there and review your results to fine tune it.
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You got it... you're within just a few points of your target and that's quite fine.
It's often the case that adjustments have to be made to the recipe based on real-time results. Because I usually estimate efficiency conservatively , I'm often at higher gravity coming into the boil. As a result I don't finalize my hop additions until I actually know the pre-boil gravity. It's not that a few points either way would make a huge difference but it's easy to make an adjustment if needed when things turn out other than expected. Same with final volume and OG. I often end up with higher gravity and will top up accordingly, depending on the beer and the volume needed.
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If you have the "tiltpi" server, it has the ability to make multiple calibrations at different temps. Gets the tilt much more accurateThanks Minbari. Yep. A quick update...this morning, moments after pitching, I took a sample from my conical fermentor spigot. Put in the fridge for a bit and went back 15 mins later.....the heavy hop debris sank to bottom......took a dropper from the top of clear beer and put it on the refractometer and viola it is near 1.053!!!! Yippee!! This clone has 2.2 oz of cascade at 30 mins and another 2.2 oz at flame out so the bottom of the sample is pea soup.
