BIAB Mashing Out

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LittleRiver said:
I use a roller mill with a .025" gap, and yes there's a fair amount of flour.

Make getting a mill a priority. Your efficiency will increase, and you can buy/store grain in bulk without worry of it going stale, since you'll be able to crush it whenever you need it.
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Good deal! I have looked at a low entry cost for something like that such as a corona mill. I know it's not as big and bad as other options, but for around $30 with a corona mill can I accomplish the finer crush?
 
Absolutely! The much maligned Corona-type mills can do an excellent job at producing a very good crush with a minimum of flour all the way up to making it all flour.
 
Oginme said:
Absolutely! The much maligned Corona-type mills can do an excellent job at producing a very good crush with a minimum of flour all the way up to making it all flour.
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Great to hear! Trying to keep costs in check lately with first little one arriving any day. I'll try to configure it to run on a drill.
 
soccerdad said:
Very interesting data points. Looks like anywhere from 2 points to 10 points, but a bunch of different processes as well.
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I mash out based on this information, and I usually hit my predicted OG. I could change my malt bill instead but I'm not really in a hurry on brew day anyway.
 
I had stopped the mash out step as the most I ever got was 2 points, but like shetc says, I'm not in a hurry. May try again.
 
So just for a private test, I am brewing a Pilsner this morning that calls for pre-boil gravity of 1037 at 70% mash efficiency.
At 60 minutes I was at 1040
I made a quick run for ice but was only gone 10 min at most.
Bumped temp to 168 and was at 1044 (This may be a combo of longer mash and bump in temp)
After sitting for 10 minutes at the higher temp .. still 1044
 
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I also lift my bag out and start heating my wort at the same time, and have had consistent results and beers that I’ve been stoked about (i.e. way tasty).
 
BowAholic said:
I always leave the bag in the kettle until I reach mash out temp, then pull and drain while raising to boil. I have been getting good efficiency/conversion doing this.
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BowAholic said:
I always leave the bag in the kettle until I reach mash out temp, then pull and drain while raising to boil. I have been getting good efficiency/conversion doing this.
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I've been very curious about this approach as well. I do BIAB method. How does raising the temp to 170F improve efficiency? Does it cause the alpha amylase enzymes to increase in productivity because they usually work at higher temperatures. Just curious. Would like some insight behind the method. Thanks!
 
John Burns said:
I've been very curious about this approach as well. I do BIAB method. How does raising the temp to 170F improve efficiency? Does it cause the alpha amylase enzymes to increase in productivity because they usually work at higher temperatures. Just curious. Would like some insight behind the method. Thanks!
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If you don't get complete conversion of starch to sugar within the allotted mash time, a mash out can sort of supercharge the completion (at least until the amylase enzymes are completely denatured.) The limiting step in conversion is gelatinization of of the starch, as the enzymes cannot act on un-gelatinized starch. Gelatinization proceeds from the surface of the grits towards the center, and the larger the grit, the longer this takes. With the very fine crushes that can be used with BIAB, gelatinization can occur much more quickly, and with fine enough crushes mash outs provide no benefit. Some malts can also have starch with higher gelatinization temps, and if you have any of these, they may not completely gelatinize during the mash. A higher temp rest can gelatinize more of these stubborn starches, thus improving your conversion efficiency.

Net: If conversion is complete at the end of the mash, a mash out will not increase your efficiency. If conversion is incomplete, then a mash out is likely to increase your efficiency.

Brew on :mug:
 
Doug is spot on.

It’s probably faster to try a 90 minute mash vs a 60 min + mash out as a first step.

It’s far less work at least.

if you can pick up 5% more efficiency with a 30 minute longer mash time, that could be very well worth it.
 
My last few batches I have been getting low final gravity readings. First batch that had this problem I was using my original dial thermometer to get strike and mash temp readings. I thought I was dead on, but then took a mash temp reading with my LavaTools PT-09 and realized I was off. After brew day, I calibrated my dial thermometer and realized that I mashed too low.

For my next brew, I bought a ThermoWorks RT610B-12 thermometer for strike and mash temps. Checked the calibration when I received it and it was right on. I thought this would solve my low FG issues.

I do BIAB brewing and wrap the brew kettle in blankets to hold the mash temperature. My typical temperature drop is only 2 degrees in 60 minutes. I'm very happy with that and don't plan on changing anything there.

The last batch I brewed was an expect 1.012 and I finished at 1.008. I'm fairly confident my mash temperature was good and I don't see any signs of infections in any of my brews. I started thinking about doing a mash out. I did read this thread and see that most agree it's not necessary. I don't sparge or mash out, I simply pull the bag and let it hang over the brew kettle while I bring the wort to a boil.

What occurred to me is that the grain in the bag is slowly cooling as it drips into the brew kettle. As the grain is hanging and temperatures are dropping, am I getting additional fermentable sugars that I don't want? Should I do a mash out and then pull the bag to see if I get better results?
 
wsmith1625 said:
My last few batches I have been getting low final gravity readings. First batch that had this problem I was using my original dial thermometer to get strike and mash temp readings. I thought I was dead on, but then took a mash temp reading with my LavaTools PT-09 and realized I was off. After brew day, I calibrated my dial thermometer and realized that I mashed too low.

For my next brew, I bought a ThermoWorks RT610B-12 thermometer for strike and mash temps. Checked the calibration when I received it and it was right on. I thought this would solve my low FG issues.

I do BIAB brewing and wrap the brew kettle in blankets to hold the mash temperature. My typical temperature drop is only 2 degrees in 60 minutes. I'm very happy with that and don't plan on changing anything there.

The last batch I brewed was an expect 1.012 and I finished at 1.008. I'm fairly confident my mash temperature was good and I don't see any signs of infections in any of my brews. I started thinking about doing a mash out. I did read this thread and see that most agree it's not necessary. I don't sparge or mash out, I simply pull the bag and let it hang over the brew kettle while I bring the wort to a boil.

What occurred to me is that the grain in the bag is slowly cooling as it drips into the brew kettle. As the grain is hanging and temperatures are dropping, am I getting additional fermentable sugars that I don't want? Should I do a mash out and then pull the bag to see if I get better results?
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If you start heating your wort as soon as you pull the bag, that is pretty much equivalent to heating the wort to mash out prior to pulling the bag, as far as the effect on wort fermentability. If the wort that drains slowly from the bag over time actually is more fermentable, it's a small fraction of the total wort volume, so will have minimal effect on the fermentability of the total wort volume.

If you want to try something that might actually "quench" the enzyme action, calculate how much boiling water you need to raise your mash to 170, withhold it from the mash, and add at the end of the mash to raise the temp to mash out "instantly."

Brew on :mug:
 
Running the full volume up to 160 for a few minutes, then ramp to 170 will boost conversion efficiency by a measurable amount and it happens faster than the same rest at say 155. It is LIKE a mash out process wise but for a different purpose.
 
Bobby_M said:
Running the full volume up to 160 for a few minutes, then ramp to 170 will boost conversion efficiency by a measurable amount and it happens faster than the same rest at say 155. It is LIKE a mash out process wise but for a different purpose.
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This is true, unless the conversion is already at 100%, which is often the case with very fine crushes. It can be especially useful if you have malt that has some fraction of starch granules with higher gelatinization temp. Not all grain is like this, and I don't think it's easy to find data on the grain that indicates if it does or not (unless you can get the DSC curve for the gelatinization temp test, which will have a big lower temp hump, and a smaller higher temp bump. Look at the left curves, the right ones are for a rerun.)

Differential-scanning-calorimetry-thermograms-of-prime-starch-from-nonwaxy-high-amylose.png


Brew on :mug:
 
I grind pretty damn fine and I'm nowhere near 100% converted at 152F in 60mins. There is a typical stall for me between 40 and 60mins so at 40, I slowly ramp over about 10mins to 160, hold for 5, ramp to 170 over 10. That gets me an average of 10% more conversion in the same 60 minutes. This is with Simpsons GP, Muntons Maris, Briess 2row FWIW.
 
Bobby_M said:
I grind pretty damn fine and I'm nowhere near 100% converted at 152F in 60mins. There is a typical stall for me between 40 and 60mins so at 40, I slowly ramp over about 10mins to 160, hold for 5, ramp to 170 over 10. That gets me an average of 10% more conversion in the same 60 minutes. This is with Simpsons GP, Muntons Maris, Briess 2row FWIW.
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Thanks Bobby. I think I'll give that a try and see how it goes. I may also buy some iodine tincture and start testing my mash before boiling.
 
Reviving this thread.

Yesterday I used my new 16 gallon kettle, so I can finally do full volume mash. After my 60 minute mash, I heated the wort up to 170 while stirring my grains, then pulled the grain bag out and let it drip into the wort while bringing it up to boil. My pre-boil gravity was a higher than expected 1.042 anticipated gravity, 1.055 measured gravity). My efficiency was probably higher due to milling the grains almost to flour.

I didn't squeeze the bag this time just to see the difference. There was definitely still wort in there after the 60 minute boil. I squeezed it a little just to see what was left in there before composting it. If I had to guess, there was 1/4 gallon or more stull stuck in there.
 
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Apple_Jacker said:
Reviving this thread.

Yesterday I used my new 16 gallon kettle, so I can finally do full volume mash. After my 60 minute mash, I heated the wort up to 170 while stirring my grains, then pulled the grain bag out and let it drip into the wort while bringing it up to boil. My pre-boil gravity was a higher than expected 1.042 anticipated gravity, 1.055 measured gravity). My efficiency was probably higher due to milling the grains almost to flour.

I didn't squeeze the bag this time just to see the difference. There was definitely still wort in there after the 60 minute boil. I squeezed it a little just to see what was left in there before composting it. If I had to guess, there was 1/4 or more stull stuck in there.
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1/4 what (cup, qt, gal, liter) still stuck in there?

Brew on :mug:
 
I'm new to all-grain brewing and chose to go BIAB.
I just made my second batch a few days ago.
I have a Hullwrecker 2 roller mill set to .028" and did a single pass on my grain bill.
I mashed for 90 minutes at 152° F and at the end of the mash I just lifted the bag and squeezed it pretty well, I did not 'mash out' or sparge.
My measured conversion efficiency came out to 82%.
I'm not sure if I should do anything else to increase that efficiency or just call it good-to-go.
 
AZ Maverick said:
...
My measured conversion efficiency came out to 82%.
I'm not sure if I should do anything else to increase that efficiency or just call it good-to-go.
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Are you sure you are talking about conversion efficiency, and not mash efficiency? Mash efficiency is the product of conversion efficiency and lauter efficiency. 82% is terrible for conversion efficiency, but is good for mash efficiency. How did you measure the efficiency you reported?

Brew on :mug:
 
doug293cz said:
Are you sure you are talking about conversion efficiency, and not mash efficiency? Mash efficiency is the product of conversion efficiency and lauter efficiency. 82% is terrible for conversion efficiency, but is good for mash efficiency. How did you measure the efficiency you reported?

Brew on :mug:
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I'm new to this all-grain world, so excuse my newbieness....
I used the Brewer's Friend 'Brewhouse Efficiency Calculator', specifically the efficiency for 'Conversion' and/or 'Pre-Boil' as they were the same for me.
I rechecked and I did make a mistake which lowered my conversion efficiency down to 79.7% (I accidentally included grain absorption water).
Using the same calculator, my 'Brewhouse Efficiency' ended up at 77.58%.

I saw this on BYO.com for extraction efficiency and figured "OK, no big deal - I'm in the ballpark" - is this info not correct?
Capture.JPG
 
AZ Maverick said:
I'm new to this all-grain world, so excuse my newbieness....
I used the Brewer's Friend 'Brewhouse Efficiency Calculator', specifically the efficiency for 'Conversion' and/or 'Pre-Boil' as they were the same for me.
I rechecked and I did make a mistake which lowered my conversion efficiency down to 79.7% (I accidentally included grain absorption water).
Using the same calculator, my 'Brewhouse Efficiency' ended up at 77.58%.

I saw this on BYO.com for extraction efficiency and figured "OK, no big deal - I'm in the ballpark" - is this info not correct?
View attachment 722127
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Brewer's Friend uses the term "pre-boil efficiency" for what BeerSmith (and others) call mash efficiency. It's the percentage of maximum possible extract (sugar) that the grain bill could create that makes it into the BK. Conversion efficiency measures how much of the maximum potential extract actually gets created in the mash. A good conversion efficiency is near 100%. Lauter efficiency measures the percentage of extract that was created in the mash that actually makes it into the BK. Lauter efficiency is always less than 100%, because some of the extract created in the mash always remains in the grain bed in the absorbed wort. Mash (pre-boil) efficiency is equal to conversion efficiency times lauter efficiency.

Brewer's Friend does a pretty good job calculating mash (pre-boil) efficiency, but it does not correct for the moisture content of the grain. This causes Brewer's Friend to underestimate the actual mash efficiency. However, BF does not calculate conversion efficiency correctly. The proper way to calculate conversion efficiency is presented here.

Brew on :mug:
 
doug293cz said:
Brewer's Friend uses the term "pre-boil efficiency" for what BeerSmith (and others) call mash efficiency. It's the percentage of maximum possible extract (sugar) that the grain bill could create that makes it into the BK. Conversion efficiency measures how much of the maximum potential extract actually gets created in the mash. A good conversion efficiency is near 100%. Lauter efficiency measures the percentage of extract that was created in the mash that actually makes it into the BK. Lauter efficiency is always less than 100%, because some of the extract created in the mash always remains in the grain bed in the absorbed wort. Mash (pre-boil) efficiency is equal to conversion efficiency times lauter efficiency.

Brewer's Friend does a pretty good job calculating mash (pre-boil) efficiency, but it does not correct for the moisture content of the grain. This causes Brewer's Friend to underestimate the actual mash efficiency. However, BF does not calculate conversion efficiency correctly. The proper way to calculate conversion efficiency is presented here.

Brew on :mug:
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Now I know why a good brewday starts with a beer -- it makes the math a lot easier to ignore.
 
doug293cz said:
Brewer's Friend uses the term "pre-boil efficiency" for what BeerSmith (and others) call mash efficiency. It's the percentage of maximum possible extract (sugar) that the grain bill could create that makes it into the BK. Conversion efficiency measures how much of the maximum potential extract actually gets created in the mash. A good conversion efficiency is near 100%. Lauter efficiency measures the percentage of extract that was created in the mash that actually makes it into the BK. Lauter efficiency is always less than 100%, because some of the extract created in the mash always remains in the grain bed in the absorbed wort. Mash (pre-boil) efficiency is equal to conversion efficiency times lauter efficiency.

Brewer's Friend does a pretty good job calculating mash (pre-boil) efficiency, but it does not correct for the moisture content of the grain. This causes Brewer's Friend to underestimate the actual mash efficiency. However, BF does not calculate conversion efficiency correctly. The proper way to calculate conversion efficiency is presented here.

Brew on :mug:
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OK - Thanks for that information.
I ran the math from your link using my actual BIAB kettle values and ended up with a first wort conversion efficiency of 94.7% using the approximation formula and 94.1% using the full accurate formula.
I think I now understand a bit more about the first wort conversion and efficiency measurements....
 
But in the case of BIAB, if I remove the grain bag at the end of the mash would I not be stopping the enzymatic activity of the grains?
 
ScrewyBrewer said:
I have not done a mash-out in years. In the end, the extra effort never seemed to make a measurable difference
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Same here.

When I moved to BIAB I was doing a mash out. It was what I did with fly sparging. I thought that maybe it would help with a little extraction, conversion, and/or head retention. It did not add too much more time and effort (I could elevate the bag and stir while adding heat). But then I started doing a lot more small batch stove top batches where it would be a pain if I wanted to lift the grain bag while heating, so I did not do mash outs for those batches. I did not really notice a difference one way or the other, so I stopped doing a mashout for my 5 gallon batches, and I did not really notice a difference.
 
pedrovic said:
But in the case of BIAB, if I remove the grain bag at the end of the mash would I not be stopping the enzymatic activity of the grains?
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No. Very early in the mash, the majority of the enzymes are released into the water/wort. So, removing the grain from the wort will not stop enzymatic action. The enzymes in the wort will continue to act on long chain sugars already in the wort. What will stop is the solubilization of gelatinized starch. Thus the SG will stop increasing (if it hasn't already maxed out), but fermentability of the wort will continue increasing (unless the extract has already been reduced to fermentable sugar and limit dextrins.)

You can start heating the wort to a boil as soon as you pull the bag, and you will denature the enzymes in about the same amount of time as if you did a mash out.

Brew on :mug:
 

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