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First mini BIAB - very low GIB. Can it be rescued?

Post #1 made 11 years ago
by Adamjohn
I am currently in the boil process for my first Mini BIAB. However it isn't going to plan.
My Gravity into boil was predicted to be 1.027/8 but I have achieved 1.013. It was a 90 minute mash at 66c. I dropped to 65 by the end of the mash.

Put the kettle onto boil and as it was coming to a boil took the OG which was 1.013.

Any ideas on what has gone wrong are appreciated :-) And is there anything I could do to save this brew? Off the top of my head I can only think of adding some sugar? DME would require a trip the the HBS which is shut at the moment.

I will upload the biabacus file, but the basics are:

It is for 9L VIF

Brewer:
Style: Bitter
Source Recipe Link:
ABV: 4.1% (assumes any priming sugar used is diluted.)

Original Gravity (OG): 1.04
IBU's (Tinseth): 31.2
Bitterness to Gravity Ratio: 0.78
Colour: 12.2 EBC = 6.2 SRM

Kettle Efficiency (as in EIB and EAW): 87.1 %
Efficiency into Fermentor (EIF): 78.5 %

Note: This is a Pure BIAB (Full Volume Mash)

Times and Temperatures

Mash: 90 mins at 66 C = 150.8 F
Boil: 90 min
Ferment: 14 days at 18 C = 64.4 F

Volumes & Gravities
(Note that VAW below is the Volume at Flame-Out (VFO) less shrinkage.)
The, "Clear Brewing Terminology," thread at http://www.biabrewer.info/" onclick="window.open(this.href);return false;

Total Water Needed (TWN): 15.32 L = 4.05 G
Volume into Boil (VIB): 14.93 L = 3.94 G @ 1.028
Volume of Ambient Wort (VAW): 9.99 L = 2.64 G @ 1.04
Volume into Fermentor (VIF): 9 L = 2.38 G @ 1.04
Volume into Packaging (VIP): 8.33 L = 2.2 G @ 1.008 assuming apparent attenuation of 80 %

The Grain Bill (Also includes extracts, sugars and adjuncts)

Note: If extracts, sugars or adjuncts are not followed by an exclamation mark, go to http://www.biabrewer.info" onclick="window.open(this.href);return false; (needs link)

95.1% pale malt (5 EBC = 2.5 SRM) 1473 grams = 3.25 pounds
4.9% crystal malt (150 EBC = 76.1 SRM) 75 grams = 0.17 pounds

The Hop Bill (Based on Tinseth Formula)

31.2 IBU Golding Flowers (5.26%AA) 21.9 grams = 0.773 ounces at 90 mins
0 IBU Fuggle Flowers (5.21%AA) 4 grams = 0.14 ounces at 0.1 mins

Mash Steps

Mash Type: Pure BIAB (Full-Volume Mash) for 90 mins at 66 C = 150.8 F

Miscellaneous Ingredients

Chilling & Hop Management Methods

Hopsock Used: y

Chilling Method: water bath (Employed 0 mins after boil end.)

Fermentation & Conditioning

Fermentation: Safale S-04 for 14 days at 18 C = 64.4 F

Secondary Used: No
Crash-Chilled: No
Filtered: No
Req. Volumes of CO2: 1.5
Serving Temp: 18 C = 64.4 F
Condition for 28 days.
Consume within 6 months.
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Last edited by Adamjohn on 09 Jun 2014, 00:42, edited 1 time in total.

Post #2 made 11 years ago
by JackRussel
A hydrometer is usually calibrated to be accurate at either 16c or 20c if my memory serves correct. If you measured your specific gravity at mash temperature then your reading will be far from accurate. Somewhere in the general ballpark of 1.030 would be closer to your true gravity reading when you correct for temperature. I say general ballpark because the further you are from the calibration temperature, the less accurate temperature compensation will be.
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Post #3 made 11 years ago
by Adamjohn
JackRussel wrote:A hydrometer is usually calibrated to be accurate at either 16c or 20c if my memory serves correct. If you measured your specific gravity at mash temperature then your reading will be far from accurate. Somewhere in the general ballpark of 1.030 would be closer to your true gravity reading when you correct for temperature. I say general ballpark because the further you are from the calibration temperature, the less accurate temperature compensation will be.
I had cooled down the sample to 25c before taking the reading then used a calculator to change for the temp. I am just cooling down a sample now for the end of the boil. Depending on the result I think I will add some sugar to the FV with the wort and see how it turns out. Then try and learn from today! :scratch:
Last edited by Adamjohn on 09 Jun 2014, 01:58, edited 1 time in total.

Post #4 made 11 years ago
by JackRussel
If you cooled the sample down then that is a huge difference. Did you stir well before taking your sample? The heavier sugar might be at the bottom of your pot, while the watery wort is at the top. Other than that you may have a lot of un-milled grain or a PH problem with your water/mash.
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Post #5 made 11 years ago
by Adamjohn
Thanks! I think you have correctly identified my mistake. I didn't stir before taking the sampe :headhit:

I have now taken the post boil sample and it is 1.037, which although still low is much nearer to the estimated 1.040. :)

Post #6 made 11 years ago
by JackRussel
Glad to hear your OG is much closer than it was looking like it might turn out. Stirring your mash every 15 minutes or so might help with both problems here.
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Post #7 made 11 years ago
by Adamjohn
Okay, I will try that next time. I was so concerned about temperature loss during the mash that as soon as I had the lid on and the pot insulated I didn't dare touch the damn thing!

Post #8 made 11 years ago
by Adamjohn
One more question regarding gravity :)

I took one more gravity reading. This was performed using the liquid left in the pot with the trub. I left behind about 1.5l as I didn't have a sieve. I then took a gravity reading with this and it came out at 1.040! Previous to taking the reading I had stirred a whirlpool which was then left for 20 minutes for the crap to settle in the middle of the pot before I siphoned down the side. So it would have definitely been well mixed. The sample was obviously more cloudy than the previous post boil sample but wasn't thick. Would there be any reason why this reading wouldn't be accurate? Unfortunately I didn't take it from the FV as I had forgotten and already pitched the yeast!

After all that I was looking at my numbers. Unfortunately I forgot to note down some things, but going on how much went into the FV - biabacus predicted 9 litres in the FV with 0.99 kettle to fermentor loss. Well I got just shy of 9l but I had 1.5l kettle to fermentor loss, so it is pretty much bang on. I am very impressed with the spreadsheet, without it planning this brew would have been pretty much impossible! I had tried with another piece of software and it differed quite a lot.

It has been a fun learning experience. Now all I can do is wait and hope I end up with a drinkable beer! Thanks to all of you :thumbs:

Post #9 made 11 years ago
by jhough
:champ: :champ: adamjohn ...glad to hear it turned out well. We all do not "HIT" our expected readings . DWRAHAHB :peace: Sometimes those that are not perfect are the best ones. ....Let us know how the final product turned out !!! :pray: :pray:
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Post #10 made 11 years ago
by stm
Adamjohn wrote:I was so concerned about temperature loss during the mash that as soon as I had the lid on and the pot insulated I didn't dare touch the damn thing!
This is what I do (and, I understand, most other BIABers). Once the mash is all over, bag/grains out, and ramping up for the boil, then you can do a stir and measure your gravity. No great rush.

And if you get a couple of points difference between measured and estimated, or even between two measurements that ought to be the same, then that is no big deal either.
Last edited by stm on 11 Jun 2014, 16:26, edited 1 time in total.
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Post #11 made 11 years ago
by PistolPatch
Adamjohn wrote:I took one more gravity reading. This was performed using the liquid left in the pot with the trub. I left behind about 1.5l as I didn't have a sieve. I then took a gravity reading with this and it came out at 1.040!
One thing you will learn on this site is that single measurements on a brew cannot be trusted and your brew is a great reflection of that. The BIABacus allows several opportunities for you to measure volume and gravity (one without the other is meaningless - read first half of this post). In your early days of brewing, if you take these measurements, you can become lazier, faster :) - you will find out if you have a problem in your brewing practice if there is one faster, and if you don't then you can relax. You will also see how much numbers can vary on a single brew.

As for stirring, my advice is you must stir when starting out as, if for no other reason, it forces you to pay attention to your brew (I still always check and stir and I am in a hot climate!) Any time I have found an efficiency problem in someone else's brewing, this is one of the causes. Many people don't stir during the mash but when I reflect on those brewers (and they are all great) they will be the first to admit that they don't have a good handle on numbers* etc. - they make beer, it tastes great and that is all that matters to them and that is fine/good.

:peace:
PP

* Think I better update Some Common Reasons for a Low Efficiency Reading after pondering on that!
Last edited by PistolPatch on 12 Jun 2014, 17:38, edited 1 time in total.
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Post #12 made 11 years ago
by Adamjohn
I just remembered I hadn't updated this post, apologies for that.

Firstly, thank you all for your advice and expertise, this forum is a fantastic resource and has been instrumental in helping me understand the basics of brewing and the BIAB way of doing it.

Now onto the beer,
Image
Not the best photo as the light was poor. Not clear but not too far off. Definitely a nice malty bitter, a bit of biscuit and a slight hoppy dry finish. Very drinkable, it ended up about 3.7% I believe which is .3% lower than I was aiming for. But as a first attempt I was very happy with the beer. It was a Big Lamp Bitter clone beer from Brew Your Own British Real Ale.

I have since done another BIAB again from BYOBRA this time the Youngs Special clone. Pretty much to the letter but dry hopping with quite a lot of fuggles (I had them to use up). It turned out really nice, a possible slight 'grainy' taste which is similar to something I was picking up in the first beer, but as a beginner I don't know if that should be there or not. Once again though I was off the percentage alcohol by about .3 But unfortunately I have been lazy and not really taken the necessary measurements, so on future brews I will try and be much better in that regard.
Last edited by Adamjohn on 16 Oct 2014, 17:58, edited 1 time in total.
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