2nd BIAB session with some questions..

so i'm sitting here scratching my head at some of the numbers i reached today after putting them back into beer smith... first off, here was my recipe i created. it's a Rye IPA

Recipe Specifications
--------------------------
Boil Size: 5.30 gal
Post Boil Volume: 3.64 gal
Batch Size (fermenter): 3.00 gal
Bottling Volume: 2.55 gal
Estimated OG: 1.060 SG
Estimated Color: 14.3 SRM
Estimated IBU: 81.8 IBUs
Brewhouse Efficiency: 70.00 %
Est Mash Efficiency: 81.7 %
Boil Time: 70 Minutes

Ingredients:
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Amt Name Type # %/IBU
6.00 g Gypsum (Calcium Sulfate) (Mash 60.0 mins Water Agent 1 -
5 lbs Pale Malt (2 Row) US (2.0 SRM) Grain 2 66.7 %
1 lbs 8.0 oz Rye Malt (4.7 SRM) Grain 3 20.0 %
12.0 oz Carared (20.0 SRM) Grain 4 10.0 %
4.0 oz Chocolate Rye Malt (250.0 SRM) Grain 5 3.3 %
0.50 oz Columbus (Tomahawk) [15.00 %] - First Wo Hop 6 48.9 IBUs
0.50 oz Chinook [11.10 %] - Boil 20.0 min Hop 7 19.9 IBUs
0.60 Items Whirlfloc Tablet (Boil 15.0 mins) Fining 8 -
0.34 oz Citra [15.60 %] - Boil 10.0 min Hop 9 10.4 IBUs
0.16 oz Citra [15.60 %] - Boil 5.0 min Hop 10 2.7 IBUs
0.16 oz Chinook [11.10 %] - Boil 0.0 min Hop 11 0.0 IBUs
0.16 oz Citra [15.60 %] - Boil 0.0 min Hop 12 0.0 IBUs
0.15 oz Columbus (Tomahawk) [15.00 %] - Boil 0.0 Hop 13 0.0 IBUs
1.0 pkg Safale American (DCL/Fermentis #US-05) Yeast 14 -
0.75 oz Columbus (Tomahawk) [15.00 %] - Dry Hop Hop 15 0.0 IBUs
0.34 oz Chinook [11.10 %] - Dry Hop 5.0 Days Hop 16 0.0 IBUs
0.34 oz Citra [15.60 %] - Dry Hop 5.0 Days Hop 17 0.0 IBUs


Mash Schedule: BIAB, Medium Body
Total Grain Weight: 7 lbs 8.0 oz
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Name Description Step Temperat Step Time
Saccharification Add 23.38 qt of water at 158.6 F 152.1 F 90 min
Mash Out Heat to 168.0 F over 7 min 168.0 F 10 min


my first BIAB i didn't have good efficiency... it only worked out to 70%. so i based this recipe around 70% being that's what i got last time. for this round, i upped my mash time to 90min because i thought i had a decent grain crush... as the day's moving along, it seems like all is well, mashed for 90 min, hovered right at the 152 maybe 153 side for a bit of it, and hit pre boil gravity and volume this time. (1.041 & 5.3G). i did a 70 min boil, which only brought it down to 1.051 & 4.3G. so i'm off by quite a bit of the estimated OG of 1.060.

some interesting points. if i run brewhouse efficiency on the numbers from today, i come up with 82% which is right at what beer smith estimated. so that's good and i improved my efficiency! but why didn't i reach the estimated OG?

also if i go back into beer smith and change the total efficiency to what i actually achieved today (82%) it REALLY changes EVERYTHING! throws it all out of whack, including the estimated efficiency. why is that?

the color seems WAY darker than what i expected too... but really i'm just looking for a good drinking beer as long as it taste's good!

just looking for more input to learn more about what's actually going on over here!
cheers and thanks guys!
matt

One thing I notice is your boil off/evaporation rate is incorrect. You did a 70 min boil and went from 5.3 gal. to 4.3 gal., so your boil-off rate is slightly below one gallon per hour. Beersmith is estimating going from 5.3 gallons to 3.64 gallons, probably about 1.5 gallons of boil-off per hour. That should be adjusted.

Also, your recipe assumes a post-boil volume of 3.64, but only 3 gallons into the fermenter. The loss to break material and transferring is probably more like a cup or two. I'd also adjust the volume loss between the fermenter and bottling.

Keep tweaking the numbers and you'll get your system dialed in.

ok this is a good start... yeah. looks like the boil off is set at 1.66. i don't see a way to adjust it in the recipe... only in the equipment profile, do you know is this the only place, or is there a way to update this recipe, to look at more proper numbers?

also about the break material, this was the first time i used whirl floc, and yeah, it brought all the break material together at the bottom, but not so much in a cone in the center. there was probably about 3-4 inches (in a 11.5" diameter kettle) of trub/break material. as i was siphoning it into the fermenter, i couldn't leave it all in the the kettle, because that was A LOT of wort, so i ended up siphoning more into the break material, leaving about an inch on the bottom. took a while to settle in the carboy. after about 2-3hrs, it's settled into about 3 inches on the bottom of the carboy. still seems like a lot to me. now at about 5hrs, it's all floated to the top and starting to move around as the yeast is going to town! does all that sound about right? again, still learning! thanks guys!

The boil off is adjusted using the equipment profile. Your final gravity number is off because of the equipment profile and batch size selected. If you were to have boiled your wort down to 3.64 gal., you would have been much closer to the gravity predicted by Beersmith. So, adjust your equipment profile and batch size accordingly and your results will be more in line with beersmith's calculations.

The fermentation you described sounds perfectly normal.

so still scratching my head a bit with the numbers.... i know it really doesn't matter as long as i'm making a good beer... but when i was shooting for an OG of 1.060 and only hit 1.050, i want to try to fix it for future batches. now with adjusting the equipment profile, it's kind of throwing the number out even more... the estimated OD didn't change, it's still estimating 1.060, but the IBU's went way up to 79. color darker, and still saying 6.3% which i'm only predicting 5.2% now... still don't why i only hit 1.050. also if i put the numbers into the online brewers friend recipe page (which i think is kind of cool too), it predicts an OG of 1.064... humm...

also i saved the recipe as a new file, all the exact same ingredients, but changed the efficiency to what i actually got, 82%, and updated the equipment profile for 1g boil off etc, but the numbers are even more off, even further away from what i achieved... and all in all for my 2nd BIAB session, i was super happy i hit my pre boil gravity with doing the 90 min mash this time but any thoughts on these numbers:

Boil Size: 4.81 gal
Post Boil Volume: 3.64 gal
Batch Size (fermenter): 3.00 gal
Bottling Volume: 2.55 gal
Estimated OG: 1.071 SG
Estimated Color: 14.3 SRM
Estimated IBU: 73.7 IBUs
Brewhouse Efficiency: 82.00 %
Est Mash Efficiency: 95.7 %
Boil Time: 70 Minutes


and wow for the good news, talk about an active fermentation on this one now that yeast is going to town on this beer! looks awesome!

thanks again

jmfitzgerald said:

Post Boil Volume: 3.64 gal
Batch Size (fermenter): 3.00 gal
Bottling Volume: 2.55 gal

Click to expand...

This needs to be fixed, you shouldn't be losing .64 gallons from post-boil to fermenter and another .45gallons from the end of fermentation to bottling.

jmfitzgerald said:

so still scratching my head a bit with the numbers.... i know it really doesn't matter as long as i'm making a good beer... but when i was shooting for an OG of 1.060 and only hit 1.050, i want to try to fix it for future batches. now with adjusting the equipment profile, it's kind of throwing the number out even more... the estimated OD didn't change, it's still estimating 1.060, but the IBU's went way up to 79. color darker, and still saying 6.3% which i'm only predicting 5.2% now... still don't why i only hit 1.050. also if i put the numbers into the online brewers friend recipe page (which i think is kind of cool too), it predicts an OG of 1.064... humm...

Click to expand...

I already answered this in post #4, "If you were to have boiled your wort down to 3.64 gal., you would have been much closer to the gravity predicted by Beersmith", but I'll try to clarify. When you boil the wort, the sugar remains, but the water volume is reduced. This creates a more concentrated wort which gives you a higher OG. The recipe in Beersmith thinks you're boiling the wort down to 3.64 gallons for a 3 gallon batch, but you only boiled the wort down to 4.3 gallons leaving you with the same amount of sugar in a greater volume of water. This leads to a lower OG because the wort is more diluted. How does this translate to Beersmith? The batch size and trub loss need to be adjusted to reflect the batch size you want and to more accurately estimate your trub loss. Transferring your wort from boil kettle to carboy should only result in a small amount or loss, .64 gallons is way too much in my experience.

Most of the questions are answered above. As for the beer looking dark - it always looks darker in the fermenter because of the quantity and opacity. It will look lighter when in a smaller quantity, eg when poured into a pint glass ;-)