Ah yes, I'm not getting conversion (I think?)

I've done 2 AG BIAB brews now, and am thinking I need to do something different. I don't think I am converting very well at all.

The first brew I got 53% efficiency, and the second I got 73%. However, both have an odd taste, kind of like malt o' meal or something. It's really prevalent in the second, which is a lighter session beer- it's more hidden in the first.

Also, fermentation for both stopped above 1.020, even with good temp control and aeration, etc.

They each are hazy- not chill haze, but a permanent haze even when it's warm. No clearing even after awhile in the fridge.

This last point, put together with John Palmer's troubleshooting appendix and these other things, made me think that perhaps I am extracting starch from the grain, not converting it to sugar, and then brewing with that.

Main question: Does my diagnosis make sense? I only have read about the hydrometer finding the sugar content, but wouldn't it also register starch content? So I would end up with a reading of 1.041, think I have 73% efficiency, but 50% of those are unfermentable starches that never converted, for instance.

--
Some things I've thought about/questions you'd probably ask anyways-

• I don't have iodine to test it with, but I'll be picking that up before the next brew day.
  
• My first mash was at 154° for 60 minutes. Second was at 154° for 90 minutes.
  
• My thermometer is calibrated at freezing, and is within 1 degree of where boiling should be at my altitude (even pulled out the GPS to get the altitude), so that should be pretty close.
  
• My mash thickness has been in the 1.5-2 qts/lb range.
  
• I sparged & mashed out on the second, but not the first.

If there is starch in the beer, it will still be there. So get some iodine.

david_42 said:

If there is starch in the beer, it will still be there. So get some iodine.

Click to expand...

Any suggestions to convert more starch?

recipe, grains used, sparge temps - details needed or everyone is just guessing.

Here are links to my brew logs.
Brew 1 - Pecan Nut Brown
Brew 2 - Short Sleep Ale

My main question, I guess, is, is my diagnosis right? Am I getting (and measuring) starches that haven't been converted to sugar?

Did you do a starch conversion test on your mash ?

Did you do what David42 asked & test to see if you've still got starch in one of the finished beers?

I guess the main point that everyone else is trying to make is: it's hard to tell without more data. Have a read through the articles at http://braukaiser.com/, especially the ones about efficiency. Use his efficiency spreadsheet on future brews to determine where your losses really are.

While we're on the subject of being exact, GPS altitude is about as good as referencing a map to calibrate your thermometer. Sure, it'll get you close, but pressure altitude (more specifically, atmospheric pressure) is what's really important. A good, current weather report will include that information.

find out the moon phase too while you're at it. JK.

James,

I use a similar technique as yourself. My first BiaB AG registered a 55-60% efficiency. I've tweaked my technique as I have progressed and my latest batch, AG#6, was up to 70%. And had I not needed .75 gallons of top off water I think I would have been 75-80.

I mash with only 1.3 quarts of water to pound of grain. By request, my grain is crushed at .035 to maximize extraction. I also try to keep my strike water to 152 for 75 minutes and I double batch sparge (10min at 170).

I'd say that even with Irish Moss additions my BiaB batches look hazy at first. However, this seems to really resolve itself the more time you give it in bottle. For instance, I did a Belgian Blonde Ale in April that looked hazy and tasted excessively yeasty for 2-3 months. But, since the end of summer it's very clear and quite tasty. Best brew I have made and it was only my second AG brew! I'd recommend just giving it time.

Also, recently I mashed my Oatmeal Stout way too high at 158 for 60 minutes. After two weeks in primary it seemed stuck at 1.020. I expected it because of the higher temperature mash. However, after two more weeks in primary (total of four) I bottled it last night at 1.013. Even without noticeable fermentation, something was going on. Now, I'm not sure I like it at 13 as I liked it at 20. I tend to like sweet Oatmeal Stouts so we shall see how it turns out. Again, I'd recommend giving it more time in primary.

Sounds like you are keeping good notes. It might take time, but I think you'll get to where you want to be with your technique. Good luck.

Yuri_Rage said:

While we're on the subject of being exact, GPS altitude is about as good as referencing a map to calibrate your thermometer. Sure, it'll get you close, but pressure altitude (more specifically, atmospheric pressure) is what's really important. A good, current weather report will include that information.

Click to expand...

I know- that was tongue in cheek (it said it was only accurate within a couple hundred feet, anyways). I also factored in the pressure to get the boiling temp.

bking said:

find out the moon phase too while you're at it. JK.

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I think that just affects hydrometer readings, not boiling temp.

XXguy said:

Did you do a starch conversion test on your mash ?

Did you do what David42 asked & test to see if you've still got starch in one of the finished beers?

Click to expand...

I did not do a conversion test, and I misread David42's suggestion. I will do one once I get some iodine... but that may be a while.

Yuri_Rage said:

I guess the main point that everyone else is trying to make is: it's hard to tell without more data. Have a read through the articles at http://braukaiser.com/, especially the ones about efficiency. Use his efficiency spreadsheet on future brews to determine where your losses really are.

Click to expand...

This will be my work break reading for the next... however long it takes.

Thanks all for your advice!

jamesnsw said:

This will be my work break reading for the next... however long it takes.

Thanks all for your advice!

Click to expand...

http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Measuing_conversion_efficiency

There's a chart there that is more effective than an iodine test. If the crush isn't fine enough and there is still starch that hasn't gotten into your mash water the iodine won't tell you it's unconverted.

Also, since you're doing BIAB, you could easily dough-in at a lower temperature then ramp up to get to the sacchrification rest. I've noticed that doing a three-step mash gets me much higher efficiency. 122 for 10 minutes, then 140 for 30 then 155 for 45 gets me 80%, while a single infusion at 155 for 90 minutes only gets me 65%. I'm using a cooler as a mash tun and not BIAB, so YMMV.

GrizlyGarou said:

http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Measuing_conversion_efficiency

There's a chart there that is more effective than an iodine test. If the crush isn't fine enough and there is still starch that hasn't gotten into your mash water the iodine won't tell you it's unconverted.

Click to expand...

Better to quote the rest of that section about conversion efficiency:

Note that a mash should never result in a positive iodine test (starch or large detxtrines present in the wort) as this can lead to diminished beer quality while a negative iodine test but poor conversion efficiency shouldn't lead to quality problems. It should just lead to a poor brewhouse efficiency

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Starch that stays locked up in the grains will result in poor efficiency, but won't necessarily result in poor quality beer. I think the OP's question revolves around not knowing if he got good conversion, and not knowing if unconverted starch got into his beer.

Interesting topic.

Yes, all the symptoms point to starch in the wort and eventually in the beer.

James,
Do you have an idea what your water is like. Alkality and hardness would be good to know. Maybe your mash pH is so out of whack that the mash is not converting as well as it should.

Kai

XXguy said:

I think the OP's question revolves around not knowing if he got good conversion, and not knowing if unconverted starch got into his beer.

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Yes, exactly.

Kaiser said:

Interesting topic.

Yes, all the symptoms point to starch in the wort and eventually in the beer.

James,
Do you have an idea what your water is like. Alkality and hardness would be good to know. Maybe your mash pH is so out of whack that the mash is not converting as well as it should.

Kai

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Good to know that my thought that starch was in the beer was correct.

I use Metro Denver water for brewing, and this is what my water looks like-
(Denver, CO, South of Mississippi from BeerTools)

Ca++ 37
MG++ 22
Na+ 22
HCO3- 100
SO4-- 51
Cl- 27
HDNS 186

Residual Alkalinity 41.95
Mash pH 5.9

The guy at the LHBS had my throw in a handful of acid malt on the last brew to help bring the pH down.

jamesnsw said:

Ca++ 37
MG++ 22
Na+ 22
HCO3- 100
SO4-- 51
Cl- 27
HDNS 186

Residual Alkalinity 41.95
Mash pH 5.9

Click to expand...

With that water and the types of beers you brewed, you mash pH shouldn’t be that high. It should be closer to 5.5. How did you test it?

The guy at the LHBS had my throw in a handful of acid malt on the last brew to help bring the pH down.

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Did you do that? And did you get a pH of 5.9 after adding the acid malt?

Kai

Kaiser said:

With that water and the types of beers you brewed, you mash pH shouldn’t be that high. It should be closer to 5.5. How did you test it?



Did you do that? And did you get a pH of 5.9 after adding the acid malt?

Kai

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The 5.9 comes from the BeerTools water profile- I haven't tested it.

I did throw in the acid malt- is that taking me in the wrong direction? I thought it would bring the pH down.

jamesnsw said:

The 5.9 comes from the BeerTools water profile- I haven't tested it.

I did throw in the acid malt- is that taking me in the wrong direction? I thought it would bring the pH down.

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How much acid malt did you add?

I don't think you need the acid malt unless you brew a very light beer. There are enough colored malts in the grists that you were using to move your pH into the 5.2 - 5.6 range.

Kai

Kaiser said:

How much acid malt did you add?

I don't think you need the acid malt unless you brew a very light beer. There are enough colored malts in the grists that you were using to move your pH into the 5.2 - 5.6 range.

Kai

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It was literally "a handful" per the directions of the LHBS guy. I think 2 oz. (He threw it in for free, so I'm not sure.)

That's good to know that I don't need acid malt.

James, have you tried using the "5.2" stabilizer?

AZ_IPA said:

James, have you tried using the "5.2" stabilizer?

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I may have to try this. How much $ does it add, approx., per brew? For some reason, online stores I've looked at don't have the weight of the product, just the price. I'm guessing $.50 or so, just wondering.

In this order:
Do an iodine test and check for conversion. If that fails, there is your problem.
If not, get Kai's efficiency spreadsheet and fill that out. That will show you where you are not getting the sugars from.
Depending on where the problem is, take steps from there.
We need that information or anything we can say is pure speculation.

Adjusting your mash pH, before knowing what your mash pH is - strikes me as kind of backwards.

Buy some pH test strips, buy some iodine, test what you're doing. Don't guess.

jamesnsw said:

I may have to try this. How much $ does it add, approx., per brew? For some reason, online stores I've looked at don't have the weight of the product, just the price. I'm guessing $.50 or so, just wondering.

Click to expand...

With your water, I don't think you need this.

Did you already rule out that your thermometer is off?

Kai

XXguy said:

Adjusting your mash pH, before knowing what your mash pH is - strikes me as kind of backwards.

Click to expand...

At this point it is not so much adjusting mash pH. It is adjusting water.

It’s similar to what we do with our hops. We estimate the bitterness that they contribute so we can design the hop bill to get us into that desired IBU range. Once we brewed the beer we can give it a taste and refine the hop bill.

The same with mash pH: we can estimate mash pH from residual alkalinity, beer color, mash thickness and some info from the grain bill. Then we can test the outcome in the mash and, if necessary, make adjustments. But hopefully our prediction was close enough that we don’t have to make any adjustments.

Buy some pH test strips, buy some iodine, test what you're doing. Don't guess.

Click to expand...

Yes, I do recommend getting strips over getting 5.2 anytime. The strips that James is looking for are the colorpHast 4.0-7.0 ones. They are fairly spot on once you add 0.3 to the reading (info here). Iodine, for obvious reasons, is a good idea too. In addition to that find yourself a piece of white chalk board chalk or dry wall. You want to do the iodine test on that since it is much easier to read and less ambiguous than the white saucer method. Here is some info: Starch Test.

Edit: this place sells and ships a box of 100 strips for $18 which is a good price: http://www.sanitationtools.com/products.asp?category=72&attriberror=true&Product=1391

Cut them in half and they'll last you for 100+ batches. This is less than 18c a batch and once you re-brew recipes you don't have to check all the time. Select pH range 4.0 - 7.0

Edit: If you look around: [ame]http://www.google.com/search?hl=en&source=hp&q=colorphast+4.0+7.0&aq=f&oq=&aqi[/ame]= you'll find other places that sell the box of 100 for ~$17-19. The home brewshop price is about $25.

Kai

Kaiser said:

With your water, I don't think you need this.

Did you already rule out that your thermometer is off?

Kai

Click to expand...

My thermometer is accurate at freezing and boiling. However, my brother had the thought that it may be that the probe is too short. I have this thermometer.

I got it not thinking I would do more than PM, so it's possible that the 5" stem is too short to get more than just the surface temp. Do you think this is likely enough that I should get a new thermometer?

Thanks all for your suggestions. I'll be adding some of these things to my Christmas list

jamesnsw said:

My thermometer is accurate at freezing and boiling. However, my brother had the thought that it may be that the probe is too short. I have this thermometer.

I got it not thinking I would do more than PM, so it's possible that the 5" stem is too short to get more than just the surface temp. Do you think this is likely enough that I should get a new thermometer?

Thanks all for your suggestions. I'll be adding some of these things to my Christmas list

Click to expand...

I don't know if you mentioned the type of mash tun that you use, but in my large rectangular tun, the temperature is pretty even throughout after a stir. However my tall round tun has problems with getting the same temp throughout without a **** ton of stirring. If I stick the probe 4" in, it will read a very different temperature than 12" in. Lots of stirring to get the temp even throughout from the start of the mash.

jamesnsw said:

I got it not thinking I would do more than PM, so it's possible that the 5" stem is too short to get more than just the surface temp. Do you think this is likely enough that I should get a new thermometer?

Click to expand...

No, I have a short thermometer too. And it has to be off quite a bit for you to not get conversion.

Kai

z987k said:

I don't know if you mentioned the type of mash tun that you use, but in my large rectangular tun, the temperature is pretty even throughout after a stir. However my tall round tun has problems with getting the same temp throughout without a **** ton of stirring. If I stick the probe 4" in, it will read a very different temperature than 12" in. Lots of stirring to get the temp even throughout from the start of the mash.

Click to expand...

It's a turkey fryer pot. I'm going to stir a lot more than I have been next time (aka not leave the house for an hour).

Kaiser said:

No, I have a short thermometer too. And it has to be off quite a bit for you to not get conversion.

Kai

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Good to know. Thanks!

I too mash in a turkey fryer pot and wrap it in blankets for the mash rests.

Kai

Got pH strips and iodine today. Iodine test came back positive. pH strips (not the ones you suggested, Kai, my LHBS didn't have them) gave me a reading of 4.6 for the finished beer.

I added some blueberries to this one, hoping it will hide the starchiness a bit... we shall see.

jamesnsw said:

Got pH strips and iodine today. Iodine test came back positive. pH strips (not the ones you suggested, Kai, my LHBS didn't have them) gave me a reading of 4.6 for the finished beer.

I added some blueberries to this one, hoping it will hide the starchiness a bit... we shall see.

Click to expand...

Positive for starch in the finished beer?

Also, we don't care too awful much about the pH of the finished beer.

Are we sure its not a problem of too high a mash temp so there's a lot less fermentable sugar? That's not a huge temp difference from 154 to have that happen. You'd end up with a heavy beer, but depending on the IBU's it might not taste 'sweet' just real malty.

Yes, positive for starch in finished beer. Didn't get iodine to test while mashing, thought 90 minutes was long enough. Learned my lesson.

It doesn't taste malty, really. More like Malt'O'Meal cereal, I'd say.

Could it be too fine a crush?

Hardleft said:

Could it be too fine a crush?

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no.....