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Help troubleshooting my latest mash; incomplete starch conv.

Post #1 made 9 years ago
by GlowingApple
I've run a few BIAB brews now, changing a few variables here and there to solve some issues that came up. My latest BIAB went fairly well, but I got low mash efficiency (66.8% compared to mid-70's for previous brews). I've read about a lot of things I can try to improve that for future batches, so I'm not too concerned about that.

More concerning with this brew, I never saw full starch conversion, even after 105 minutes. The iodine test showed positive (on chalk) throughout the mash. At first I thought I was doing something wrong with the test, but after cold-crashing and a week in the keg I still have hazy beer. Warming the beer up doesn't change the amount of haze so I'm pretty sure it's starch haze.

Grain bill:
  • 8.75 lbs US Pale 2-row malt
    1.7 lbs Crystal 60L malt
    1.6 oz Chocolate malt
I used 6.6 gallons strike water (2.50 qt/lb), starting with RO water and adjusting with water salts to fit a balanced amber ale (from Bru'n water). The pH was 5.3-5.4 throughout the mash. I heated my strike water to 158.6 ˚F (70.3 ˚C) in an 11 gallon stainless kettle and doughed in. My target mash temp was 152.0 ˚F and I hit it pretty closely.

Here's what I saw throughout mashing:
  • Dough in: 152.2 ˚F (66.8 ˚C)
    30 min: 150.0 ˚F (65.6 ˚C); SG 1.035
    60 min: 148.1 ˚F (64.5 ˚C); SG 1.041
    90 min: 146.3 ˚F (63.5 ˚C); SG 1.043
    105 min: 145.0 ˚F (62.8 ˚C); SG 1.044
Temperature loss was 4.1 ˚F/hr (2.3 ˚C). This seems high, but I don't think this is the cause of the incomplete conversion? I have my kettle insulated with a multiple-layer Reflectix wrap (on the cover too), but the bottom just rests on the stove. I might try setting the kettle on a thick towel next time to see if I can decrease the temperature loss further.

Like I said the iodine test never came back negative, but I decided after 105 minutes to just go forward. I think the cause of the low efficiency (at least partly) and the haziness is incomplete starch conversion.

Any suggestions on what I should do differently for future batches?
Last edited by GlowingApple on 16 Feb 2016, 08:53, edited 1 time in total.

Post #2 made 9 years ago
by joshua
GlowingApple, Your Mash dropped from 152F to 147F, is Not a problem, except The beer will have a bit Higher ABV and a bit lower Body.

What was your Predicted Original Gravity OG?
What was your Final Volume, and What was your Sparge Volume if you sparged.

As 1.044 is pretty Good for a thick Mash(2.4qt/Pound).

I prefer to mash Full Volume BIAB around 4 qt/Pound.
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Post #3 made 9 years ago
by GlowingApple
My predicted OG (calculated at 73% mash efficiency) was supposed to be 1.055 for 5 gallons. My actual OG came in at 1.052. I was expecting a pre-boil gravity of 1.047. Didn't sparge, just squeezed the bag a lot.

The FG came out to be 1.009, lower than the 1.012 I was expecting. It definitely is a little dry, but that seems to work fine for this style.

I used 2.5 qt/lb because 6.6 gallons was the full volume boil. With grain absorption and boil-off I hit my target volume pretty close. If I used a thinner mash it would take me a lot longer to boil off the extra volume.

Would the temperature drop account for the incomplete starch conversion? 4 ˚F/hr doesn't seem to be too bad from most posts I've seen, and I've read that keeping the temp constant for the first 15 min is the most important. I assume that if starches were not converted it would be the cause of the hazy beer I have?

EDIT: OG predicted to be 1.055; had mistakenly listed 1.056 before
Last edited by GlowingApple on 16 Feb 2016, 16:11, edited 1 time in total.

Post #4 made 9 years ago
by joshua
Have you Cold Crashed the beer for a week to see if the Haze, really was Starch, or just Proteins that did not Cook out?

What style of Yeast did you use? Because some varieties take a long time to drop out.

Just one other Question,

Did you Stir the Mash thoroughly every 15 minutes, to break up the Mash, to get the Sugars mixed, and get the remaining Enzymes Mixed too??

The BIG boys, stir the Mash Tuns Continuously.

FWIW, I have mashed for 3 hours at 142F, and Made the Driest Beer with NO body....Just Like "Bud Light".
Image
Last edited by joshua on 16 Feb 2016, 11:52, edited 1 time in total.
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Post #5 made 9 years ago
by GlowingApple
The beer has been in the keg at 40 ˚F for over a week now. Since the dip tube touches the bottom of the keg anything that settles out should be tapping out first. If it's protein haze it should go away as the beer warms up and the proteins become more soluble, but I'm seeing no change with temperature.

I stirred the mash every 30 minutes. I wanted to make sure the temp didn't drop too much and every time I open the kettle to stir it loses a lot of heat. I just purchased a long whisk, so my next brew I can try stirring with that instead of my mash paddle to see if that helps. I'm hesitant to stir too much and let the temperature drop more though... I'd much rather have a fuller-bodied beer; not looking for a bud light clone!

EDIT: Forgot to answer, I used Safale US-05 for the yeast. Cold-crashed with gelatin at 32 ˚F for 2 days, then racked to the keg where it's been at 40 ˚F for 12 days now.
Last edited by GlowingApple on 16 Feb 2016, 15:16, edited 1 time in total.

Post #6 made 9 years ago
by Mad_Scientist
If you feel like it, post your BIABacus ver. T with all the information you know and we'll take a look at it.

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Last edited by Mad_Scientist on 19 Feb 2016, 02:27, edited 1 time in total.
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Post #7 made 9 years ago
by PistolPatch
Woo! Woo! Woo! Hold the horses!!! :lol:

First up, quarts per pound is irrelevant in BIAB. You use all the water you need for the brew and that's it. Period. (Josh brews a different way to others. In other words, he keeps boiling until he reaches his pre-boil gravity. He likes doing it that way for some reason but it makes it really confusing when he talks about his method here.) So let's forget about quarts per pound and mash thickness.

By the look of things, GlowingApple is definitely using some other software besides the BIABacus. To answer your question properly GA, we'll need to know what software that is and all the information you put into it. For example, we don't know the Volume into Boil you were expecting. We also don't know the expected and actual Volume at Flame Out and your Gravity at Flame-Out. Until we have that extra info, we won't be able to tell if this is a 'real' efficiency problem or just a terminology problem.

So GA give us much info as you can re your software, expected volumes and gravities versus your actuals and we'll get this nailed quickly ;).
PP

P.S. Once you've done that, while you're waiting for an answer, study the Clear Brewing Terminology thread. That thread will help you see how the terminology used in other brewing software can really cause major problems for you.
Last edited by PistolPatch on 16 Feb 2016, 13:12, edited 1 time in total.
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Post #8 made 9 years ago
by GlowingApple
I used BeerSmith for this batch. It's actually the first batch that I've used BeerSmith (used BrewTarget previously), so I'm not entirely sure I had things set correctly. Previously with BrewTarget I've had mash efficiencies of 75% and 73% (efficiency into boil I believe it would be?). I didn't use the BIABacus for this batch, but I attached version PR 1.3T with my information filled in.

I'll give all the info I have here too. Please let me know if I'm using any terminology incorrectly!

I started with 6.6 gallons of room temp water and brought it up to strike temp. I doughed in by adding my grain (crushed directly into a grain bag), stirred everything well with a mash paddle and covered the kettle. After 30 min I stirred the mash, took a temperature, removed a small sample and took gravity, pH, and ran an iodine test. Covered the kettle and waited another 30 min. Stirred and tested every 30 minutes, and after 105 minutes decided just to go ahead with the boil.

Removed the grain bag, squeezed as much as I could into another kettle, and poured that bag into the main kettle. At this point my volume (Volume into Boil) was 5.75 gallons. I calculated my grain absorption at 0.08 gal/lb. Gravity of a sample of the wort was 1.044 (Gravity into Boil). An iodine test of the wort, after removing the grain bag, was still positive.

Boiled for 60 minutes and my final volume (Volume at Flame-Out) was just over 5 gallons (guessing about 5.1 gallons). Calculated my evaporation rate at 0.65 gal/hr. Once cooled, gravity of the ambient wort was 1.052. I forgot to plan ahead for cooling loss, and lost about 1.5 quarts (~0.4 gal) to trub, but didn't top off, so my volume into fermentor was about 4.5 gallons.

Let me know if I missed any info! Thanks so far for all the help!
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Post #9 made 9 years ago
by PistolPatch
Good on you GA. I'll check out your BIABacus later today but can you save your recipe from BeerSmith as a .bsm file and then upload it here? Unfortunately, this is the only way to check things easily in BeerSmith. Good info above btw and that will be a great help.

Do an advanced search of early posts done by me that contain the words "batch size". There should be some good rants there. This is one of many major terminology problems that Clear Brewing Terminology prevents.

Let us know if you have any problems posting the recipe as a .bsm file.

:peace:
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Post #10 made 9 years ago
by GlowingApple
I have BeerSmith 2, so I've included a bsmx file. I also included a bsm file (for BeerSmith 1), but I'm not sure if any settings are lost saving to the old version. I hadn't used BeerSmith before, so I might not have all the values entered (namely I didn't use it for water volumes, but calculated on my own... hence forgetting the cooling loss).

Thanks again!
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Post #11 made 9 years ago
by GlowingApple
Ah, I see what you mean about batch size! When I was brewing extract I always boiled 3 gallons (cold from the tap), and just topped off to the 5 gallon line in my primary. So I always assumed when a recipe gave a batch size they meant VIF, and never considered they could mean VAW instead. As a partial-boil extract brewer I never even measured a VAW.

Now that I'm brewing all-grain I've been working on being more calculated and analytical about my process. Though I wonder if it would be better to aim for a slightly lower than 5 gallon VIF and just top off before measuring my OG? This would account for differing boil-off rates (due to humidity changes), differing grain absorptions (might not squeeze the same each time), etc. Or is it better to calculate everything to get 5 gallons VAW and just not worry if I end up a little lower or higher in the fermentor?

Post #12 made 9 years ago
by PistolPatch
Lol! That's great you read up on the batch size. That plus some errors in major brewing software over many years have basically resulted in a complete mess where two brewers using the same terms can mean very different things without either of them realising they are even speaking two different languages. Crazy stuff :evil:.

Okay, your files are very good. As a matter of interest, this site used to try and teach people how to use BeerSmith but there were way too many problems with it. We ended up creating the BIABacus because of that. While it is only a spreadsheet, it is very powerful and despite the visual assault, much faster to learn and much harder to use incorrectly. I've had a look at your BeerSmith file and you 've filled it out really well. I'm going to use your BIABacus file though as the BIABacus estimates a lot of things very well such as kettle efficiency and so it is much easier to see if you have a real problem and there does seem to be one.

The first thing I look for to identify if there is a real efficiency problem is Section P.
2016-02-16_19-42-16.jpg
It's great that you took several measurements as we can get some confirmation. See how EIB and EAW are very close, 63.9% and 66.9%? These are both "kettle" efficiencies and, in a perfect world of measurement, they would always be the same. Usually we just get them within 5% of each other and you've done better than that so this tells us that we can rely on your readings to a degree assuming your instruments are right. Also notice how they are way lower than the expected 78%? The BIABacus is set up so that you actually should get better than the expected so as you don't get caught in the position of a weak wort. Instead you usually end up with a bit more than you need which is a good, safe way to play a brew as things like evaporation rates can vary greatly from day to day.

So, we definitely have an efficiency problem. Not enough sugars are leaching from the malt into the liquor/water. If this has not happened on your prior brews though, then it isn't even worth a second thought as the cause will most likely be an incorrectly weighed grist, more common than you think.

So, that's the first question. Has this been happening on every brew? Have your volumes been about right but your gravities always low or was this the first time it has happened? From what I have read, this is the first time so we can't conclude anything on this brew unless you did actually weigh your grains in a manner where you were able to double-check the weight.

If it happens again though and you are very confident you have double-checked the weight of your grains and volumes into the mash, then it would be time to examine each of the points in Some Common Reasons for a Low Efficiency Reading carefully. For now though, I reckon forget about it and brew again. Forget the iodine test as well. There are lots of ways that can lead you astray :).

At the end of the day, this current brew is going to be fine. You simply got a bit less volume and a few gravity points lower so it's definitely going to be well within the ball-park :drink:.

Good stuff!,
PP
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Last edited by PistolPatch on 16 Feb 2016, 20:12, edited 1 time in total.
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Post #13 made 9 years ago
by GlowingApple
I don't think I weighed my grains out incorrectly, but it's certainly possible! I'm assuming I had low starch conversion though due to the iodine test coming back positive and my beer being hazy in the keg (likely not protein haze because it doesn't change with temperature; likely not yeast haze because it's not decreasing as the keg sits cold). Too little grain shouldn't cause starch haze, right?

My previous batches gave decent efficiencies (73 and 75%; not ideal, but seems to be typical for BIAB?), though I changed my process a bit to get where I am now. My first batch I didn't wrap my kettle and heated the mash continually. I also did a 168 ˚F (75.6 ˚C) mash-out at the end. I ended up making a very very astringent oatmeal stout; I think I scorched my grain while heating. My second brew I made a kettle cover from Reflectix, only stirring the mash every 30 minutes, and tried a "dunk sparge" in 170 ˚F (76.7 ˚C) water, but didn't realize how small my 5-gallon kettle is with that much grain... and spilled a bunch on the floor. Since I reserved some water for sparging I did a thicker mash. Oddly enough my kettle only lost 2.6 ˚F over an hour, even with the lower volume of water.

This batch I wanted to do a full-volume mash again, completely skip the mash-out, no-sparge, just squeeze the grain bag well (picked up some heavy duty PVC gloves). I used a full volume mash, but ended up losing more heat. I'm only stirring at dough in, and every 30 minutes. Should I be stirring more? Wouldn't this cause a higher temperature loss? Or is it better to stir more despite that?

I'm pretty happy with how this beer turned out taste-wise. It's a little on the dry side, but that works ok for this style. I'm still trying to figure out my all-grain brewing process, so given this result I'm not sure if I should try this same process again, go back to a process I was using before, or try something new for the next brew.

Post #14 made 9 years ago
by joshua
GlowingApple, " Too little grain shouldn't cause starch haze, right?" The amount of Grain does NOT cause starch Haze.

Incomplete Conversion is the Only Source Of Haze.

Too short a Mash duration, lack of agitation, or too Low a water to grain ratio.

If you can find a Pizza Screen, or a Cake Rack to fit In the kettle on the Bottom, your Bag will never Scorch.

The Alpha and Beta Enzymes will Work fully, between 148F and 154F, so the small drop in your Mash Temperature was not a big problem.

You Cannot Skip the Mash-out, as you need to Pull the Bag below 178F, SOME TIME, A rest time is Unnecessary, if you stir the Mash often, to equalize the temperature, Pull the Bag above 172F to be sure the enzymes have been broken down.

The Dry side batch, came from a mash temperature lower than 150F, and is way to control the Style of beer you Want.

One Thing I forgot to Ask.......How Accurate is your Thermometer?

If if reads High, your Mash will be Cooler and take Longer, and May have helped to cause your Troubles.

Good Luck on your Next Batch!!
Image
Last edited by joshua on 17 Feb 2016, 06:10, edited 2 times in total.
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Post #15 made 9 years ago
by Rick
Perhaps I'm missing something, but it seems you are sounding the alarms after being slightly low on a single brew. I'd not worry about my process until at least a repeat. Anomalies happen, it could be anything at this point.
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Post #16 made 9 years ago
by GlowingApple
@joshua:

I set my grain bag on a trivet, so I'm not worried about it burning, but the first batch was very astringent. I'm guessing since I was heating from the bottom the grain got hotter than 170 ˚F and I extracted tannins. Seems a lot of people do not do a mash-out, so I wasn't sure how necessary it was.

My thermometer seems to be fairly accurate. Last I calibrated it, in ice-water it read 32.10 ˚F and in boiling distilled water it read 211.00 ˚F.

@Rick:

Yes, I'm sure I'm being more worried than I should be... The beer turned out quite tasty anyway! Since I'm still somewhat new to all-grain brewing I haven't decided on all the details of my process yet. From what I've read it seems people's approaches are so varied and I'm not really sure what steps are necessary or which approach is best. Given I changed my process from the first two brews and my efficiency went down, I'm not sure if one of the steps I changed is the culprit or if I've added some new issue.

Post #17 made 9 years ago
by Manor
MODNOTE:I've just moved all the last posts to the chat thread as the concept of gravity points hasn't been explained to GlowingApple. This and the numbers not being finalised can make for a confusing read that is not needed yet anyway. We probably should use The The Nonsense / Chat / Fast Answer / Guest Thread a lot more :think:.
Last edited by Manor on 18 Feb 2016, 10:16, edited 1 time in total.

Post #18 made 9 years ago
by Rick
How are you measuring volume, and are you doing so at the center of the kettle (not the side wall)? I know the DIY etching is a thing now, and many brewers don't realize that the kettle needs to be level for it to be accurate. Just throwing that out there, and maybe we should add that to Some Common Reasons for a Low Efficiency Reading that Pat linked us earlier.

[MODNOTE: Sentence above copied back here from the chat thread.Rick's suggestion here added to the list :thumbs:.]
Last edited by Rick on 18 Feb 2016, 10:25, edited 1 time in total.
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Post #19 made 9 years ago
by GlowingApple
I'm measuring volume with markings I made on my mash paddle. I always measure in the center. I'm not sure my volumes are real accurate, but I have markings every half-gallon, so I should be able to judge down to the quarter gallon or better.

Post #20 made 9 years ago
by Mad_Scientist
You can do a simple verification. Enter 19.4 cm into Section U, that's 18.93L / 5G, then mark your paddle at 19.4 cm.

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