Post #51 made 11 years ago
Lumpy5oh, I "First Wort Hop" my Bitterness Hops, and FlameOut/Whirlpool/Hop Stand my Flavor hops and Toss the Aroma hops in at 153F/67C, as I no-chill.
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Post #52 made 11 years ago
If your volumes do check out, I think we're going to have to look at your water chemistry and get that sorted.

As for the GIB, try to recall the brew day. Did you collect all of the runnings and stir everything very well before taking your sample?

I've gotten wildly different readings in the past, and it was surely because I did not take the sample at the right time. GIB would always be well off for me, but GAW would be within a point or two. Once I realized my errors in process, things have been a bit better for me.

Either way, we'll hit the bullseye here ... eventually.
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Last edited by Rick on 14 Oct 2014, 23:05, edited 1 time in total.
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Post #53 made 11 years ago
mally wrote:kaiserben -I have just re-read the thread from the start, and I noticed you mentioned taking your volume readings by looking at the markers on your fermenter & kettle. Do you use any other method to measure volume, or just these?

Would it be possible to weigh your vessel(s) when empty, then double check afterwards when they are full or at a stage to take a measurement? i.e. your VIF on bathroom scales.
It is possible that you have more liquid than those markers say, and thus your only thing to change for the future would be boil vigour.
For first 2 brews I used a measuring jug (a pre-marked cube) to put 4L into my 19L kettle. I measured the height with a stainless steel ruler and just extrapolated that figure (at 1.45cm = 1L) up to what I needed to go into my mash. Obviously extrapolating like that is likely to magnify any slight margin of error.

For the latest brew I used a measuring jug to measure out 12L. I figured out that "1.45cm = 1L" was actually more like "1.4cm = 1L" and went from there.

That little change from 1.45cm to 1.4cm, assuming mash volume should be 16L (for example), means I would have added about 1L too much in my previous mash. A fairly big/obvious error at these small batch volumes.

But that leaves me with the latest brew still having issues.

So I'll definitely attempt to weigh it in next time.
Rick wrote:As for the GIB, try to recall the brew day. Did you collect all of the runnings and stir everything very well before taking your sample?
I'm 99.9% sure I collected at the right time.

I guess there's a chance it wasn't stirred as well as it could have been (ie I'd stirred plenty earlier in my process, particularly approaching mash out, but didn't stir between squeezing/dripping my bag and collecting the sample).
Last edited by kaiserben on 15 Oct 2014, 07:59, edited 1 time in total.

Post #55 made 11 years ago
Just concentrating on my Xcm = 1L figures mentioned in my post above (where I'd had it as 1.45cm = 1L, then corrected it to 1.4cm = 1L).

My 19L kettle has a height of 25cm. Simple mathematics suggests 25/19 = 1.3158cm/L

1.3158 is a long way off the "corrected" 1.4cm that I used most recently (and even further from the earlier 1.45cm I was using originally).

In fact, if I used 1.4cm = 1L to fill my kettle to it's 19L capacity then 1.2L would flow over the rim of the kettle!!!

Assuming 1.3158cm is correct for 1L, then-

Schwarzbier: I used 1.5L too much TWN.
ESB1: I used 0.6L too much TWN (I used 1.5L too much TWN on BIABacus file, but at the same time I've realised I had BIABacus set to a 60 min boil and actually did 75 mins. So adjusting BIABacus just now for a 75 min boil I can work out that I used ~600ml too much TWN. Hopefully this isn't too confusing to follow).
ESB2: I used 1L too much TWN.

I'm certain this was the problem all along; something really obvious and simple. And so easy to fix. It would mean my measuring jug is not to be trusted for measuring volumes (as suggested by Mally, and maybe others earlier in this thread).

Post #56 made 11 years ago
Let's hope that's your problem Ben. :luck:

Even section U/V of the BIABacus could help as this will predict your volumes too.
U = height of liquid gives volume.
V = height of headspace will give you your volume too (safer if hot liquid and closer to the lip).

I would still recommend the weighing "trick", and the beauty of this method is it doesn't matter what temperature you weigh at either (other than avoiding scalding yourself).
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Post #57 made 11 years ago
Good stuff guys :salute:

Just quickly...

You must measure the height and depth of your stock pot/kettle and type this into the BIABacus. These measurements do not lie whereas measuring jugs etc do. I have a four litre measuring jug here that actually hold only three litres. Figure that one out!

Something sold as a 19 L stock pot does not mean it is 19 L. It could be 19 L to the bottom of the handle or less - long story.

Buy a stainless steel ruler and trust in the BIABacus :).
Last edited by PistolPatch on 15 Oct 2014, 19:24, edited 1 time in total.
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Post #59 made 11 years ago
I won't be brewing again till a week after this Saturday, but will report back then if this has solved my problem.

The lesson here seems to be: Don't trust any measuring device (except for the BIABacus, of course ;) )

Post #61 made 11 years ago
kaiserben wrote:I won't be brewing again till a week after this Saturday, but will report back then...
:nup:

Ben, don't wait until then. You can check the volume right now. You already have mentioned the height of your kettle. What is the diameter? Let us know as this will tell us immediately if it was a problem or if we need to look elsewhere. Let's hope it is but don't wait until the next brew day to make sure.

So, ruler to check stockpot and bathroom scales to check fermentor. Just worry about your the stockpot for now.

:peace:
Last edited by PistolPatch on 16 Oct 2014, 17:42, edited 1 time in total.
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Post #63 made 11 years ago
Oh dear :scratch:, how did we fall down this rabbit hole?

So, kettle volumes should be fine assuming you are using a ruler? Lots of posts in this thread and I don't have time to re-read them sorry but maybe fermentor volume is playing a factor here? I don't know. But...

In post #2 of this thread I posted a link to Some Common Reasons for a Low Efficiency Reading. In that link, the following were mentioned...

1. Reading has not been confirmed. (This table shows the resulting measurements of 30 brewers mailed identical ingredients and then asked to brew the same recipe.)
2. Grain bill incorrectly weighed.
3. Thermometer not calibrated at mash temperatures. (This post shows how unreliable a single thermometer is.)
4. Hydrometer not calibrated at original gravity (or the brewer is taking gravity samples that are too hot to temperature correct.)
5. Bag is too small and restricts liquor flow. Your BIAB bag needs to fully line the kettle.
6. Bag porosity is too small. 35 vertical and horizontal threads per cm works well.
7. pH of mash has not been adjusted.
8. Estimated mash efficiency did not reflect the gravity of the brew. (A high gravity beer will have a lower mash efficiency than a low gravity beer. NOTE CAREFULLY: This point can be ignored if you are using the BIABacus as the BIABacus adjusts for gravity.)
9. The brewer is measuring 'efficiency into fermenter' rather than 'efficiency into the kettle.' The first figure is often far lower than the second.
10. The grain used has lower extract potential or higher moisture content than the specifications being used for the calculations.
11. Mash time is too short. In full-volume BIAB, mashing and sparging occurs simultaneously. Pulling your bag at 60 minutes, cuts this process too short. Allow at least 90 minutes and preferably follow with a mash-out.
12. The grain is not being agitated during the mash. Time, temperature and agitation are how we 'wash' things. Agitating the grain and checking the temperature several times throughout the 90 minute mash has no downside and should be done so as you can determine the cost of not agitating.

...

I think the next step is to reply to each and every of the above points and let us know if/how you have checked them*. This will force you to see if you have missed anything (and there is at least one thing my brain is telling me you missed without re-reading 62 posts above :o) and, it will get all of us up to date and focused again.

Let's go from there I reckon otherwise we'll be going around in circles. This thread has gone on far too long without an answer so you doing the above will allow all of us to re-group. It might take you an hour or so to write a response but detail is what will solve this one.

;)
PP

* Even if you have already written a response to any of the 12 points above, just write them again as no one can be expected to keep track of/remember, every post in this thread. Writing everything from scratch will help you as well.
Last edited by PistolPatch on 17 Oct 2014, 19:55, edited 1 time in total.
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Post #64 made 11 years ago
Actually, I'd say kettle volumes have been WRONG using the ruler until now, but only because:

I was not measuring based on the actual kettle volume. Silly me, I used a measuring jug to put what I assumed was 12L of water into the kettle. I measured that amount with a ruler and used that to calculate my required volumes. Big mistake! Mathematics indicates the measuring jug is wrong and I had too much water.

I'm certain that this was my problem all along.

I can still go through those 12 points though (but think the above was the problem)-

1. I took a few readings on each brew day for each of 3 batches and all indicated a low gravity issues.
2. 1st batch weighed by store only. Second batch weighed by store and checked by me at home.
3. Thermometer checked against 4 other thermometers at hot tap water temp, mash temp and boiling temp. My thermometer proved to be very close to others (1 other got maybe 3 degrees C higher at mash temp).
4. I cooled samples for hydro to room temp (~20C). Hydrometer itself was tested against 1 other hydrometer (they matched perfectly at OG and 1.000 in tap water).
5. If anything bag is too large for my pot. To compensate for potentially trapped pockets of grain I do make sure to get the mash paddle into every nook & cranny during the mash.
6. This is a bag bought from LHBS designed for BIAB.
7. Not checked.
8. Using BIABacus.
9. ?? I dunno. I'm not measuring efficiency as such. I'm just doing what BIABacus tells me and taking gravity readings.
11. All have been 90 minute mash times.
12. Plenty of agitating during mash. Maybe not as much in the first brew, but the next two were agitated plenty.

Where did I go wrong?

Post #65 made 11 years ago
Sounds like volume could be the issue. Unfortunately to verify this you will need to do another brew. If this fixes the issue then you're away, if not you can work your way through the list.

The tough part will be disposing of all those experimental brews but I get the feeling you'll find a way to take care of that!

Post #66 made 11 years ago
kaiserben wrote:I can still go through those 12 points though (but think the above [VOLUME] was the problem)
Nice work kaiser :salute:.

I was getting a bit lost here so after your last post am now hopeful again that it was a volume measurement problem. (If not, then 6 and 7 will be worth some investigating but I think you have it nailed).

One very good thing that has come out of this thread thanks to you Kaiser is the very simple method of testing several thermometers under hot water to find a variance at mash temp. Simple, basic and very obvious but something I certainly never thought of before.

Great stuff :thumbs:,
PP
Last edited by PistolPatch on 18 Oct 2014, 22:42, edited 1 time in total.
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Post #67 made 11 years ago
So the latest ... good news and bad here:

GIB (estimated) = 1.033
GIB (actual) = 1.030

Very happy with that.

Not as happy with this:

GAW (estimated) = 1.050
GAW (actual) = 1.042

I forgot to measure KFL or VIF (and have now squeezed the air out of my no-chill cube), but they're not going to alter my gravity.

The main thing I can see is that BIABacus estimated I'd evaporate 1.18L more than I actually did. Everything else seems pretty close to the mark.
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Post #68 made 11 years ago
Is your pot tall and narrow or wide and short?

If you reverse your current kettle diameter and heights, this would explain everything.

:think:.
PP

P.S. I have just added three new points to Some Common Reasons for a Low Efficiency Reading.
Last edited by PistolPatch on 27 Oct 2014, 19:15, edited 1 time in total.
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Post #69 made 11 years ago
PistolPatch wrote:Is your pot tall and narrow or wide and short?

If you reverse your current kettle diameter and heights, this would explain everything.
Pot definitely more wide and short rather than tall and narrow.
I measured pot again and the exact height is 25.5cm (rather than 25cm). Diameter definitely 30.7cm (rather than 31cm).

PistolPatch wrote:P.S. I have just added three new points to Some Common Reasons for a Low Efficiency Reading.
13. Grain was pre-crushed by my LHBS.
14. I just did a weight test. I put 17cms of water into my pot. That weighed in at 13.4kg (I could only get a reading of 0.0 for the empty pot, so I'm suspicious of a false reading here). I then tried filling as close to the brim as possible and got 18kg. But still no idea what the weight of the empty pot is.
15. Grain was pre-crushed by my LHBS. It was a very humid day when I brewed (but the grain had been cracked only 24 hours earlier and had been stored mostly in a cool, dry place).


I'd also like to point out that this same pot (19L pot from Big W) has been used successfully by other home brewers with no apparent issues (I've googled and trawled through forums trying to find any problems with these pots, but haven't found anything obvious).
Last edited by kaiserben on 27 Oct 2014, 22:23, edited 1 time in total.

Post #70 made 11 years ago
Damn! :)

Be nice to find out why the zero weight reading but I was hoping more that the diameter and width had been reversed. (That would have been the answer but only if you had been using the heights in Section U to fill your kettle and measure your actuals).

Maybe get some pH strips for the next brew and remember to measure the KFL and VIF as these are the best volume figures of all.

Fingers crossed,
PP
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Post #71 made 11 years ago
Alright!

So I just brewed another batch (another ESB - version 4) and my numbers were the closest they've ever been.
I also made sure of every measurement.

One major thing to note is that I let the boil run a little longer (ended up a 95 minute boil) because my volume was still 2cms too high when I was about to do my late hop addition. So I just boiled an extra 5 mins and ended up only 1mm above my target height - about as close as I reckon is realistic.

BIABacus file attached.

Mash volume and VIB slightly under expected (440ml and 80ml under respectively)
GIB was slightly under (1.030 instead of 1.033)
VFO was 110ml higher than expected (which equated to only 1mm in height)
GAW was under (1.045 instead of 1.050).

Can anyone definitely pin down why the lower than expected gravities from this info?
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Post #72 made 11 years ago
I haven't had a chance to look at the file but going by what you have written; I wouldn't sweat the gravity discrepancies. Your numbers are not far enough off to make much of a difference in the final beer. Remember also that no program or calculator is going to be exact. Although the Biabacus is a great tool with the best formulas around it is still a best guess as to what to expect.
We are not perfect as brewers and neither is our equipment. Some of the differences in the numbers could also arise from slight errors in whatever you used to arrive at your numbers.
Regardless of the numbers I am sure you are well on your way to a tasty brew!
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Post #73 made 11 years ago
If the last result was typical I wouldn't be particularly worried, but it comes off the back of worse results in terms of low efficiencies.

However I just want to point out again that this time I kept boiling the wort down (beyond 90 mins) till I reached close to my predicted VFO height. If I'd done flame out at exactly 90 minutes we'd be discussing an OG of 1.042 (I took a sample at that point so I'd have a better idea of what was happening) and I'd have an extra litre (or so, from my memory of the height at that point).

Meanwhile something else bothers me; the mash volume being 440mls under predicted stands out as quite odd to me. :think: (must be human error, ie. Me. That's quite a big discrepancy in the scheme of things).

Post #74 made 11 years ago
Hey kaiser,

Couple of things spring to mind.

It looks to me like you are looking like getting a lot of gravity points from the boil. In your example you want to go from 1.033 to 1.050. This seems a big task to me imo. Just checked my records and the most ive got is 14 points (average i get is about 8) and that was a longer boil than 90 mins. You are looking for 17 and bear in mind if your mash yields 1.030 you and now chasing 20 points from the boil. Of course every ones brew house is different with different equipment and efficiencies which will have a big factor.

Next one will probably get me in trouble but id throw in extra grain. Spoken to professional brewers and commonly if their mashes are lower than expected they will just add and extra bag of grain. Works out cheaper than paying the brewer to figure out where the efficiency is dropping. Not saying this is good practice. Id also consider giving the brew a little bump with dme if you know its low in gravity starting out. Im not talking getting it from say 1.050 to 1.052 (as mentioned by others dont sweat the small stuff) but if your after 1.050 and getting 1.038 etc. Ester flavor will be a factor with an ESB imo.

Not sure if thats made it better or worse for you but hopefully some ideas to think about.

Cheers,

Dave


kaiserben wrote:So the latest ... good news and bad here:

GIB (estimated) = 1.033
GIB (actual) = 1.030

Very happy with that.

Not as happy with this:

GAW (estimated) = 1.050
GAW (actual) = 1.042

I forgot to measure KFL or VIF (and have now squeezed the air out of my no-chill cube), but they're not going to alter my gravity.

The main thing I can see is that BIABacus estimated I'd evaporate 1.18L more than I actually did. Everything else seems pretty close to the mark.
Last edited by DaveDoran on 11 Nov 2014, 04:17, edited 1 time in total.

Post #75 made 11 years ago
Kaiser,

I looked over you BIABACUS program, and the only thing that seems out of line is the GIB...the Drop to 30 points from 33 points is 91%.

50 points at GAW being 45 is right on..(0.91*50=45.45)

If you can Check the Mash's Specific Gravity a few times during the Mash, and see how fast the conversion is taking, you may need to Mash Longer.

By the Way, any Hydrometer reading during the mash needs to be cooled....Of Course. You also can add that Sweet Liquor back to the mash since any thing added back will be boiled, and Sterilized.

JMHO.
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