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AG Starch conversion issues and PH

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Post time 2022-10-19 01:56:39 | Show all posts |Read mode
I am doing an AG mash (9 lbs corn, 8 lbs oats, 7 lbs 2 row barley malt in 12 gal water) and I am not converting starch. I steeped the corn and oats in about 10 gal water started at 205F. I added 2 tlbs limon juice.  Didn't budge the ph. I tested the lemon juice and it's ph was 7 which I found odd.  Left it wrapped in blankets overnight and in the morning temp was just above 150F so I added the malt.  PH of the mash was still 7.  Bought some citric acid at the store. Tested that before adding it.  Tested the citric acid powder it was 7. Tested citric acid in distilled water that was about 6.8.
Temp is now down to 90 and it's been 12 hours since I added the malt. I did the iodine test and it appears my starches didn't convert.
I am guessing that the ph caused either the malt not to convert the starch and/or the grains not to gelatinize but I did this recipe before without any pH adjustment and it had a low SG but converted for the most part. I thought I'd try and lower pH this time to maybe get a better conversion.  
Questions:
1) Why is my lemon juice and citric acid that I just bought from the store at a pH of 7? Has anyone else seen this?
2) Is PH the most likely the issue here or should I be looking more into other possibilities?
3) other than turning this into a sugar wash is there anything I can do to salvage this mash at this point?
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Post time 2022-10-19 02:31:30 | Show all posts
How are you testing for PH? Has that method been calibrated?
I know my water sits at about 7.2 and every once in a while I’ll throw a dash or two of citric  acid in a 6 gallon brew just because it’s laying around. You might have nosedived the ph of your water to the point of screwing yourself.Freedom had been hunted round the globe; reason was considered as rebellion; and the slavery of fear had made men afraid to think. But such is the irresistible nature of truth, that all it asks, and all it wants, is the liberty of appearing.
-Thomas Paine
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Post time 2022-10-19 03:16:29 | Show all posts
What is the SG of the mash?" you can pick your nose and you can pick your friends; but you can't always wipe your friends off on your saddle" sage advice from Kinky Friedman
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Post time 2022-10-19 03:38:11 | Show all posts
Which of the other possibilities are you considering?
Whatever your method of measuring pH may be a bit skewed.“Always carry a flagon of whiskey in case of snakebite, and furthermore, always carry a small snake.”
- W.C. Fields
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 Author| Post time 2022-10-19 03:55:46 | Show all posts
SG is 1.040 which is okay but definitely not converting all the starch. There is a noticable difference in the iodine test between a sample taken after recently stirred and after sitting a while.
I think it might be either milling is too coarse or perhaps I am converting the corn and not converting the oats. Is other words I am getting the corn to gelitenize but not the oats. I've done straight corn and barley with great success but wanted to try the oats to up my game. I figured the oats would gelitenize same as the corn.  
The ph meter I am using is on a soil tester.
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Post time 2022-10-19 04:47:42 | Show all posts
It's low but it's got alcohol in it, you went to the trouble of doing an all grain. Personally I would run it. Have never worked with oats aside from steam flaked in small amounts so not to sure on that side, corn can be difficult to convert and I have found between different bags of feed grade corn the ease of conversion varies a bit.

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 Author| Post time 2022-10-19 15:04:02 | Show all posts
I ended up pitching the yeast last night.  Don't think the PH is the issue even though I am baffled by it.  Ended up using some test strips and it still came in around 7.  I'll run it and next time I think I'll cook the corn separately for longer and hotter instead of just steeping in 200F+ water and letting it cool down to malt temp.  There are a number of recipes that just use a steeping method but I'll try a more thorough corn cook and see if that can up my SG.
I figure if I cook the corn good and well then add it to the oats and steep as before and if I get a better SG I know it was the corn that wasn't gelatinizing.  If I get the same SG then I'll have to look at if the oats are gelatinizing or if my malt isn't fully converting.  
Thanks for the help.
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Post time 2022-10-19 15:37:23 | Show all posts
I think you just figured it out.
I cook the shit out of my coarse ground corn. Get some high temp enzymes and rig a power stirrer over your pot and you’ll be good to go.
Slowly heat up with enzymes, get the corn to a rolling boil for about 20 minutes, then add your oats (or other unmalted grains) and cut the heat. Leave it alone for an hour or more. Add cold backset to help get it back down to optimal enzyme range, add more enzymes and coast down to malt temps. I also add gluco with the malts to help with conversion. Works well.
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Post time 2022-10-19 15:42:03 | Show all posts
For sure. Corn ground to a meal requires no cooking, just an occasional stir. There is enough thermal mass in your (insulated keg?) tun to maintain heat within a couple degrees or so.  But to first break up your longer starch chains for your barley to work  HTL  is called for. Also, with a high percentage of oats, a glucan rest (104-120F) for 30min will help.  Some guys do this rest separately on the stovetop then add to main mash.  
Save some of the backset from your upcoming strip and add say, 1-2qts to your next mash to acidify it.“Always carry a flagon of whiskey in case of snakebite, and furthermore, always carry a small snake.”
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Post time 2022-10-19 15:53:27 | Show all posts
The quick answer is your pH meter is not right for the application. Put it in a dark drawer and forget about it, unless your water is WAYYY out of the norm the grain itself will stabilize the pH in about the right area for conversion (it's not that sensitive anyway, especially when your talking about overnight mashes). Don't add acids or salts unless you know your water chemistry. Chances are good you are just going to make the situation worse.
Common reasons for lack of conversion are:
Too coarse of grind. Can you explain your milling process?
Missing temperatures: it sounds like you are fine on this. Verify your thermometer, boil a pot of water, check what boiling temp should be at your elevation and see if the thermometer matches. Gelling corn at 200 overnight should be plenty. I do mine around 193 and its done in 2-3 hours. I would be more concerned that you denatured your enzymes. Amalyse will die at 160°f.
Grain balls: You need to stir the bejeesuz out of your mashes, if you have chunks and lumps the chunks and lumps won't gel properly, and won't convert properly. If you are just adding hot water to grain you will never get good conversion.
Rushing things: Doesn't sound like a problem, all grain doesn't need to take days though.:)
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 Author| Post time 2022-10-19 18:36:41 | Show all posts
For milling I start with cracked corn and mill in a food processor.  Worked okay but left a lot of good size chunks while the rest was pulverized and near flour.  Food processor didn't work at all for the oats so I used a vitamix blender for the oats and barley.  the first time I did this recipe I just used the blender.  I stop before it becomes flower and still has chunks in it but that most very piece is split in some way.  
I will have to make sure my thermometer is right.  I added the malt when the needle was just a hair above 150.  10 degrees is probably not too unrealistic for a standard kitchen thermometer to be off. If that is the case, then I'm adding malt above 160.  I'll have to make sure the temp is 100% correct next time.
I use cement mixer on a drill and stir the heck out of it.  Pretty sure i'm not getting grain balls.
Sounds like next time I need to be very accurate with my temps, make damn sure I get the corn cooked and gelatinize, and get a more consistent grind size.
Thanks all for a great deal of input.
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