BIAB Mashing Out

[dwightr8]

I brewed yesterday. I took gravity readings at the end of the mash. I lifted the brew bag off the bottom of the pot and fired the propane burner. When the mash reached 170 F. I turned off the burner and set the sous vide unit to circulate at 170. After 15 minutes I removed the bag, pressed it to get out the wort and checked the gravity again. I gained 10 full points by mashing out. I usually gain at least 5 gravity points. I will continue to mash out as it improved extraction and efficiency.

 

[doug293cz]

It looks like you pressed to get the wort out after the mashout, but not after the original mash. Is it possible that the gravity change is due to the squeezing?

If the mash is "done" and adequately stirred prior to draining, then squeezing will not increase the SG, only collect additional volume at the same SG.

There never is any solid sugar in the wort that needs dissolving. The sugar is created a molecule at a time from starch that is well gelatinized, or already in solution, and those new sugar molecules are in solution when they are created. There are likely to be concentration gradients during saccharification, with higher density (SG) wort near the surfaces of the grits, or in any porosity in the grits.

Brew on

 

[johnv51]

I shared my results. Throwing shade on other home brewers doesn't make this site a more inviting place to visit.

 

[doug293cz]

I assure you, I am not trying to "throw shade." You presented your observations, and the explanations I gave (three separate posts) are totally consistent with your observations.

Brew on

 

[johnv51]

Thanks for your response. I just wanted to share that mash outs work for me.

 

[SteveH aka shetc]

If you scan through the results collected here https://www.biabrewer.info/viewtopic.php?f=51&t=1669, you will see that a mash out can increase OG by a couple of points, on the whole. It does require more time to brew so you have to decide if that is worth the effort.

 

[CarolinaMatt]

My kettle is not big enough for a full volume mash so I usually mash in about 5.5 gallons of water and then heat the other 3 gallons to 170. After my mash I pull the bag and drain/squeeze, then dunk it in the 170 deg water for about 10 minutes before drain/squeezing again and then add to my kettle for boil. When I started doing the dunk, my efficiency shot up by 10 or 15%. Perhaps the mashout temp is not necessary but it sure seems to help my numbers and I can start heating the kettle as soon as I pull the bag.

I do the same exact thing and noticed the same results! Prior to the dunk sparge I was around 70% and now I easily get 80-85% every time.

 

[LittleRiver]

I do the same exact thing and noticed the same results! Prior to the dunk sparge I was around 70% and now I easily get 80-85% every time.

If you have a fine grain crush and a good water profile you should be getting low 80's without doing separate sparge steps.

 

[CarolinaMatt]

If you have a fine grain crush and a good water profile you should be getting low 80's without doing separate sparge steps.

Have not dabbled in to the super fine crush yet -- usually a double crush at the homebrew store. When you say fine do you go as far as flour like?

 

[LittleRiver]

...When you say fine do you go as far as flour like?

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.

 

[CarolinaMatt]

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.

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?

 

[Oginme]

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.

 

[dwightr8]

I shared my results. Throwing shade on other home brewers doesn't make this site a more inviting place to visit.

Sorry for the snarky remark John. It certainly didn't add anything to the thread. Please accept my apology.

 

[CarolinaMatt]

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.

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.

 

[dwightr8]

If you scan through the results collected here https://www.biabrewer.info/viewtopic.php?f=51&t=1669, you will see that a mash out can increase OG by a couple of points, on the whole. It does require more time to brew so you have to decide if that is worth the effort.

Your link does not seem to work. I'd be interested in reading the article.

 

[johnv51]

Sorry for the snarky remark John. It certainly didn't add anything to the thread. Please accept my apology.

Thanks. Apology accepted.

 

[SteveH aka shetc]

Your link does not seem to work. I'd be interested in reading the article.

Let's try this again https://www.biabrewer.info/viewtopic.php?f=51&t=1669

 

[soccerdad]

Let's try this again https://www.biabrewer.info/viewtopic.php?f=51&t=1669

Very interesting data points. Looks like anywhere from 2 points to 10 points, but a bunch of different processes as well.

 

[SteveH aka shetc]

Very interesting data points. Looks like anywhere from 2 points to 10 points, but a bunch of different processes as well.

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.

 

[soccerdad]

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.

 

[soccerdad]

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

 

[Fewk]

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).

 

[John Burns]

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.

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.

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!

 

[doug293cz]

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!

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

 

[fendersrule]

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.

 

[wsmith1625]

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?

 

[doug293cz]

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?

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

 

[Bobby_M]

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.

 

[doug293cz]

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.

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.)

Brew on

 

[Bobby_M]

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.