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2nd BIAB Brewday - Light Rye Ale - Poor Efficiency

Post #1 made 11 years ago
by wstehling
I had my 2nd ever BIAB day yesterday and i missed on OG, both GIB and GAW pretty badly. I'm trying to sort out what happened and I think I have a decent idea of at least one contributing factor. I've posted my 1.3T file with my actuals here for post-game analysis by those that are far more experienced.

First, I had some left over grains so I examined each of the leftovers and all of them appear to be under-crushed. To my eye, it appears that about 50% of the 2-row is not crushed. The rye appears to be about 70% un-crushed and the wheat about 50% un-crushed. So that is culprit #1 that I will fix next time by either buying a mill or having the LHBS double-crush and this time I'll check it before leaving the store.

The 2nd thing, which I'm not sure on is I lost 5F during the 90 min mash, even though it was wrapped in a sleeping bag. I started at 150, expecting to mash at 149, however I would have thought that at an even lower temp that would have actually facilitated a more complete conversion. So that isn't making sense to me right now.

I did not stir during mash or mashout, only stirred while heating for mashout.

Hoping one of the experts here can review my actuals and see if anything else pops out that I'm not seeing. My volumes were pretty close to the predictions so I'm not inclined to think it was a volume issue.

This is by far the most helpful site on the interweb and the advice I've gleaned from pouring over all the threads has helped me immensely, you guys do an awesome job! So I can't wait to hear with the experts have to say here.
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Post #2 made 11 years ago
by BobBrews
wstehling,
wstehling wrote: I had my 2nd ever BIAB day yesterday and i missed on OG, both GIB and GAW pretty badly.

First, I had some left over grains so I examined each of the leftovers and all of them appear to be under-crushed. To my eye, it appears that about 50% of the 2-row is not crushed. The rye appears to be about 70% un-crushed and the wheat about 50% un-crushed. So that is culprit #1 that I will fix next time by either buying a mill or having the LHBS double-crush and this time I'll check it before leaving the store.

The 2nd thing, which I'm not sure on is I lost 5F during the 90 min mash, even though it was wrapped in a sleeping bag. I started at 150, expecting to mash at 149, however I would have thought that at an even lower temp that would have actually facilitated a more complete conversion. So that isn't making sense to me right now.

3rd I did not stir during mash or mashout, only stirred while heating for mashout.
Your first statement probably is the most important. Did you crush them yourself or at the local shop? If the shop didn't have the mill adjusted correctly than maybe a double crush would help (if they don't re-adjust it first?)

The amount of temperature drop is not that bad. In reality the majority (if not all) of the conversion was completed before the temperature was at it's lowest point. You can always uncover the pot and add heat so long as the bag is not sitting on the bottom if you blast it with propane!

The need of a stir is done to make sure the grain is properly converted. Some feel that excessive mixing drops the temperature of the mash to quickly? It's up to you to find a happy medium?

I bet that a good grind will solve you problem. Do not grind it into powder. A regular grind properly done is just fine for BIAB. Also, results vary each and every time. Don't worry about numbers being exact! Just drink more beer so you can try again! :party:
Last edited by BobBrews on 29 Apr 2014, 02:14, edited 1 time in total.
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Post #3 made 11 years ago
by wstehling
Thanks Bob, I read every post of yours that I see (along with some others here) because they are so full of excellent data, so thanks for having a look.

My LHBS milled the grain, but I didn't look at it, nor would I have really known what it was supposed to look like if I had. After comparing to some pics on the net, I most definitely think this was under-milled. The Rye is a smaller grain than the others and it looks like it passed through the rollers mostly unaffected.

I know you guys say not to get too caught up in the numbers, but I'm an engineer by trade and of German descent so precision is a big deal to me, it's in my DNA. :geek: and it further helps me to understand what tweaks have what effect. I am all about making these batches as perfectly repeateable as I can make them.

In my true engineering troubleshooting nature, I will ONLY change the milling of the grains this time and keep everything else as close to the original attempt as possible and determine the effect. I hate when people make multiple changes to things simultaneously, you can't determine the effect or the fix then.

Will report back in a couple/3 weeks when I try again.
Last edited by wstehling on 29 Apr 2014, 03:11, edited 1 time in total.

Post #4 made 11 years ago
by BobBrews
wstehling,

Engineers and stubborn German decent ones are rampant here. So strap on BIABacus and grab your hydrometer you are in good company here with those traits. Sadly I am a horseshoe and hand grenades guy. "Close is good enough!" So when you need something done right (PP or others) will help. I no longer use any software because I am lazy and rarely repeat recipes. I do have favorites but my taste buds are so bad that I wouldn't know if I repeated it anyway! :lol:

A good grind, a 90 minute mash and a 90 minute boil equal a good beer. :thumbs:

Oh! did I mention that your pH should be around 5.4 for a good conversion. :idiot: Dark grains screw up pH something fierce! Study up on that! Now, put on your train driving hat (your a engineer right?) and drive the train down the right track to brewing nirvana!
tap 1 Raspberry wine
tap 2 Bourbon Barrel Porter
tap 3 Czech Pilsner
tap 4 Triple IPA 11% ABV
Pipeline: Mulled Cider 10% ABV

http://cheesestradamus.com/ Brewers challenge!
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Post #5 made 11 years ago
by Mad_Scientist
It's interesting that you added another sheet to the BIABacus for your 'brewday checklist'. That's awesome! :clap:

As an engineer, you might want to weigh your fermentor and wort and use the new feature on the 'unit conversion' tab for your volumes. The bucket markings can not be relied upon.
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Post #6 made 11 years ago
by wstehling
That's a good idea MS. Will give that a try.

I added that checklist sheet just so I didn't miss any of the measurements I need, plus it helps keep me on task, especially when SWMBO interrupts me in mid-brew to attend to something.
I'm sure I won't need all the minute detail in it but right now as a noob it's pretty helpful.

Post #7 made 11 years ago
by PistolPatch
BobBrews wrote:If the shop didn't have the mill adjusted correctly than maybe a double crush would help?
I'd re-word that more as the following, "If the shop had a crappy mill (which they often do) then maybe a double crush would help."

I think the rest of Bob's post probably made that clear but I just wanted to re-emphasise it. With BIAB,you should be crushing like for any other all-grain so if the shop has a decent mill, you should be ordering the same crush as for any other all-grain.
I had some left over grains so I examined each of the leftovers and all of them appear to be under-crushed. To my eye, it appears that about 50% of the 2-row is not crushed.
Beautiful attention to detail wst and I reckon that is your main problem. Really impressed you discovered that.

A few other things... Small brews are really hard to measure. Normal size brews are hard enough.

In your BIABacus, you see how in Section P, EIB and EAW are ten percent different? In theory they should be the same but your records are perfectly honest. You've done a superb job at recording your measurements and because of that, we can be pretty certain that there is something wrong. (Every efficiency figure was significantly under.) I agree with Bob. I think it was the crush but your post had really got me thinking...
Last edited by PistolPatch on 29 Apr 2014, 18:21, edited 1 time in total.
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Post #8 made 11 years ago
by PistolPatch
If you are ever given the advice to double-crush, ask why.

As Bob said above, a normal grind is what you need for BIAB.

If you are picking up your grain from the shop and they have crushed it, visually inspect it like wstehling did. Look for uncrushed grains. If more than 15% are uncrushed, ask them to run it through the mill again. As I said above, a lot of shops (unbelievable) have crap mills. A good quality mill, because of its design will only require one pass on nearly all recipes.

If you have purchased online, photograph what you received and complain.

On this forum, you should post in your region if you have a retailer that crushes well. (Whoops! I don't think I have even done that :roll:.) I'm busy. you guys do it!!!
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Post #9 made 11 years ago
by wstehling
Thanks for all the replies.
The obvious starting point here is the crush, so I'll brew this again in a couple/3 weeks and this time will ensure the crush is in good shape first.

Glad I had this noob miss on a $15 batch and not a $30+ batch, but it's a good $15 lesson learned nonetheless.

I'll report back later on how the follow up attempt goes.

BTW, is there a way for me to change my handle?


Bill

Post #10 made 11 years ago
by wstehling
Ok, I bought a "cereal killer" grain mill and re-brewed this today. I saw a pretty good improvement I think in my efficiency numbers. I kept everything possible except the weather and the self-milled grain the exact same as my previous attempt in an effort to isolate a bad crush from the LHBS as being my problem last time. Bottom line is there was improvement but there is still something out of whack.

So here is the comparison:
----------------EIB EAW EIF GIB GAW
Attempt-1 - 72.0% 62.3% 57.5% 1.032 1.040
Attempt-2 - 73.3% 73.5% 70.7% 1.033 1.043

Like I said, an improvement, but there is still something wrong, my target OG is 1.052 and I'm still missing it by quite a bit.
One thing I'm kind of keying in on is my mash temps. My target mash temp for this batch is 149F. I'm puzzled that BIABacus seems to think that for my grain at 75.2F that I should strike at 150F. 1F of difference for 5.78 lbs of grain? So I'm striking at 150F and am at 144F or 145F by end of 90 min mash (insulated in a sleeping bag both times). Other mash temp calcs I've seen suggest a larger delta between strike and target mash temp. Is this a bug in the sheet?

Besides the mash temp issue above, I've done both these batches without stirring during the mash. I think that is next to try to get closer to the target OG. The grain mill and my own crush seemed to get me part of the way there, but I need to figure out the rest of this.

Thanks!

Post #11 made 11 years ago
by PistolPatch
Hi again wst,

Good work! That second attempt acts as a real validation that something is wrong so you'll need to closely examine the following which I have copied from an old thread.

In your case, pay particular attention to 3, 4, 5, 6, and 7 below.

Some Common Reasons for a Low Efficiency Reading

Firstly, never rely on a single reading on a single brew. An occasional strange reading is common. We, home brewers are trying to take measurements at a micro level. There's several points in the brew you can take gravity and volume readings so try and find two points on each brew until you have say 4 or 5 brews notched up. (And, don't be worried if you forget to measure. It's very hard for anything to go very wrong.) After say four or five brews, you'll develop an understanding of how much brew figures can fluctuate. So this is number one on the list below.

If an odd reading persists, points 2 to 10 below should be checked or re-checked.

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.

...

wst, make sure you stir the grain during the mash. You really need to do this when starting out as it is safest practice. With yur small pot, check it every 15 minutes for now. Agitate the mash, take its temperature and use your heat source and agitation to raise the temperature as necessary. After a few brews when you are sure everything is going correctly, you can then choose to slowly become less rigorous in this schedule.

[Btw, if you noticed a drop in into boil efficiecny when you became less rigorous, give the mash a good agitation and let it go for a bit longer to correct the error. Remember, time is also a big factor in sugar extraction.]

...

The BIABacus allows you to adjust the strike water calculatin depending on the type of kettle/equipment you have. In Section X, change your strike water temperature adjustment factor to 5. (You can go higher actually but it is safer to strike under than over.)
Mad_Scientist wrote:It's interesting that you added another sheet to the BIABacus for your 'brewday checklist'. That's awesome! :clap:
Wow! How did I miss taht before? That is awesome wst.

Another thing I missed is to tell you that small batch sizes are harder, number-wise and temperature-wise to control than large batches so you are doing really well.

:thumbs:
PP
Last edited by PistolPatch on 12 May 2014, 11:15, edited 1 time in total.
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Post #12 made 11 years ago
by wstehling
Thanks for the advice Pistol.

Here are my responses for #3-7:
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.
3. Going to have to check this, I've got my eye on a Therma-K with the immersible thermocouple, but that's a few months out. Right now using the 8" or so glass red spirit thermometer I have.
4. I've checked this against water at 60F, which is what my hydro is calibrated for and it was a perfect 1.000
5. Bag fully lines this kettle
6. I'll need to count them, but this is pretty coarse mesh (bought from LHBS), more coarse than the voile I use on my large kettle
7. I've never checked this, will need to do that

I haven't stirred the grain during mash, I specifically didn't during this try because I wanted my process to be a mirror of what I did during the first attempt, otherwise I wouldn't know which change had which effect.
So I will definitely be stirring from now on.

Glad you like my brewday checklist. Being noob and trying to remember to take all these measurements I created that to help keep me on task and not miss any.

Thanks!
Last edited by wstehling on 13 May 2014, 09:33, edited 2 times in total.

Post #13 made 11 years ago
by mally
Mad_Scientist wrote:It's interesting that you added another sheet to the BIABacus for your 'brewday checklist'. That's awesome! :clap:
Yep, that's got to be the best brewday checklist I have ever seen!
Great job Bill. :salute:
Last edited by mally on 13 May 2014, 14:40, edited 1 time in total.
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Post #14 made 11 years ago
by PistolPatch
wstehling wrote:BTW, is there a way for me to change my handle?
PM BIABrewer. They would have to do it for you.

Great to see you worked through the list.

3. Better off buying several cheap thermometers of different brands before you buy one expensive one.
4. Like thermometers, a hydro reading properly at one gravity does not mean it will read accurately at another.
7. pH strtips of the right sort are easier/cheaper than an actual pH tester. See here for right sort to buy.

When I started out, I had a brewday checklist about eighty lines long. Hold on! I think we still have it on the site as "The Checklist". My goodness, more work :lol:.

:luck: on the next one!
Last edited by PistolPatch on 15 May 2014, 16:35, edited 1 time in total.
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Post #15 made 11 years ago
by wstehling
I did a freezing point and boiling point calibration test on my thermometer.

it was reading about 1F high at freezing and 3.3F high at boiling, altitude adjusted for 2700 feet. Should boil at 206.7 but was reading 210. Ignoring barometric pressure for now, but I did think about it.
I have no way to test any point in between, but it does let me compute a calibration curve based on straight line slope of the line between those two points. I know that doesn't account for deficiencies in the tube, etc. but it's about as close as i can get right now.
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