BIAB question???

[Allekornbrauer]

Hello I never try the Brew In A bag method before I am a all-grain brewer that been using the cooler mash-tun. So back to my question I understand the BIAB method but when doing it does one want to do a mash-out an if so how does one bring the temp up without burning the bag?

 

[SteveH aka shetc]

I mash out but lots of people don't. The technique is to lift the bag enough so it does not touch the bottom.

 

[4of7]

I do biab with two vessels.

 

[mongoose33]

I never did a mash-out. Not trying to be argumentative, but why would you? When I did a traditional mash tun with a batch sparge, I never did a mash out either.

 

[Oginme]

There are two main reasons for doing a mash out. The first is to increase the fluidity (lower the viscosity) of the wort to allow it to be extracted from the grain bed faster and more completely. With BIAB, you raise the bag and allow it to drip back into the pot. Since the bag drains from all area of contact between the bag and the grains, you are not limited nor constrained in the wort drainage. So bringing the wort up to mash out temperatures is not a great advantage.

The second reason is to stop the enzyme activity by denaturing the enzymes so that the wort will not continue to be converted during the long time of drainage and sparging (especially fly sparging). With BIAB, you raise the bag to drain it and then start heating the kettle up towards your boil, thus achieving the same action of denaturing the enzymes within a short time period.

 

[mongoose33]

There are two main reasons for doing a mash out. The first is to increase the fluidity (lower the viscosity) of the wort to allow it to be extracted from the grain bed faster and more completely. With BIAB, you raise the bag and allow it to drip back into the pot. Since the bag drains from all area of contact between the bag and the grains, you are not limited nor constrained in the wort drainage. So bringing the wort up to mash out temperatures is not a great advantage.

That is my view on it.

The second reason is to stop the enzyme activity by denaturing the enzymes so that the wort will not continue to be converted during the long time of drainage and sparging (especially fly sparging). With BIAB, you raise the bag to drain it and then start heating the kettle up towards your boil, thus achieving the same action of denaturing the enzymes within a short time period.

Here's why I asked that question: at the homebrew level, we're almost always trying to convert as much of the starch in the mash as we can. If your crush is good, and most BIAB'ers seem to be doing a relatively fine crush, then your conversion is, for all intents and purposes, complete by about 30 minutes.

On what would the enzymes be working that it would be considered crucial to do a mash-out to quickly denature them? I'm missing something here.

I'm doing an electric system w/ a RIMS recirculation so I no longer do BIAB, but when I did, I'd get pre-boil gravities that never varied more than a point from what I expected.

So I'm back to my original question, which is when using BIAB, why would you do a mash out? I can't see where it would have any meaningful effect, other than making the brew day more complicated, which is counter to the ease and simplicity of BIAB.

 

[hafmpty]

So I'm back to my original question, which is when using BIAB, why would you do a mash out? I can't see where it would have any meaningful effect, other than making the brew day more complicated, which is counter to the ease and simplicity of BIAB.

The “why” was answered. I do a mash out but only for the reason of wort viscosity. I have the Blichmann Tower Of Power so a Nash Out is as simple as pushing a button a couple times and it takes it from there. I get a little bit better efficiency this way. Now...mind you I have a stainless basket and not a bag so I don’t have to raise anything up or lower anything down either which again makes it easy. I also don’t squeeze the grain either so the viscosity changes from heating things up help with runoff.

As for enzyme activity...that’s a whole other issue. But my understanding is that while all the starches may be converted in the first 30 minutes or so...the enzymes are still working doing other things. Each enzyme works differently. This is what the decoction mash does. It brings part of the wort up to temps where alpha amalayse works best breaking starches into different types of sugars, dextrines, etc. But when it’s added back to the main mash the betamalayse proteins come back through and can further reduce some of the unfermentable dextrines into fermentable maltose.

So with all that said, in a traditional BIAB single-infusion mash...a mashout to stop enzyme activity is in my opinion not really needed. Pulling the bag out does the same thing. Which is why I do it only for wort viscosity.

 

[Oginme]

That is my view on it.

If your crush is good, and most BIAB'ers seem to be doing a relatively fine crush, then your conversion is, for all intents and purposes, complete by about 30 minutes.

On what would the enzymes be working that it would be considered crucial to do a mash-out to quickly denature them? I'm missing something here.

So I'm back to my original question, which is when using BIAB, why would you do a mash out? I can't see where it would have any meaningful effect, other than making the brew day more complicated, which is counter to the ease and simplicity of BIAB.

Agreed on the crush and conversion. When I mash at high temperatures, I am looking to retain more dextrins in the wort to give the final beer more body and mouthfeel. This is something that traditional brewers (fly sparge/slow draining processes) would have a hard time to control if they did not mash out and denature the enzymes.

With BIAB and the raising of temperature quickly after removing the bag of grains, these are not affected greatly as long as my process is fairly consistent. Therefore, no mash out is really needed and I agree with you that it is a complication that can be avoided. In the end, however, it is a personal choice in how you operate your process and is neither correct not incorrect.

 

[Hoppy2bmerry]

What @Oginme said. If you take the bag out to sparge that water should ideally be 170.

 

[mongoose33]

Time to brew, so I don't have time to respond in depth, but I don't quite buy the "viscosity" thing. Seems to me all you're doing when you add water for the mash out is diluting it. How much more viscous is 170 degree water/sugar than 155? Not a lot, and hard to imagine it makes much if any difference.

Anyway, off to brew. Good conversation, this--and maybe our politicians could take a lesson from people disagreeing without having to be disagreeable.

 

[Oginme]

@mongoose33, you are correct in that on a home brewing level, the viscosity really does not make that much of a difference at mash temperatures vs mash out temperatures. With a BIAB system, it really makes no difference, since by the time you raise the bag and allow to drain, the wort temperature draining from the bag is much cooler than what is in the kettle. On a commercial system, it makes a bigger difference in pumping from a mash tun to a lauter tun and then in fly sparging, since this can take a long time in a commercial system where turn around times on the mash tun is important.

Again, it comes down to a personal choice on the home brew level. I personally do not do a mash out for the reasons I stated above. Other brewers I have talked to always do a mash out. It is their choice and if they perceive an advantage, more power to them.

 

[RM-MN]

What @Oginme said. If you take the bag out to sparge that water should ideally be 170.

The water temperature is immaterial if you have already achieved full conversion. Using cool water for sparge is just as efficient as using hot because the hot wet grain raises the temperature of the sparge water pretty quickly anyway. By using the cool water you avoid the necessity of another heat source and don't have to handle the pot of hot water.

 

[SteveH aka shetc]

I mash out but lots of people don't. The technique is to lift the bag enough so it does not touch the bottom.

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.

 

[Oginme]

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.

I am sure others have achieved an improvement in mash/lauter efficiency using a mash out. I've never been able to get more than a point of added gravity when I did testing on my system a few years ago. Most of the improved gravity results would most likely correlate with coarseness of the grain crush.

 

[SteveH aka shetc]

I am sure others have achieved an improvement in mash/lauter efficiency using a mash out. I've never been able to get more than a point of added gravity when I did testing on my system a few years ago. Most of the improved gravity results would most likely correlate with coarseness of the grain crush.

I need to search the biabrewer site to see if similar data was collected for amount of crush. I think the general attitude there is that crush is not that big a deal, but I need to research more.

 

[hafmpty]

I don't quite buy the "viscosity" thing. Seems to me all you're doing when you add water for the mash out is diluting it.

I don’t actually add any water. I just turn the heat on and keep recirculating until it’s at the set temp. Then it’s done.

It’s anecdotal evidence, but for me I see about a 5%-7% increase in efficiency by bringing the wort up to ~168F. It doesn’t seem like much so I can understand the hesitation. Heck I wonder the same thing.

I wonder if it would work better at an even higher temp. The worry of tannin extraction at temps over 170F is only true without proper pH. So I wonder if 180F would give me a little bit more still.

Hope the brew went well!

 

[jimmyjusa]

I'm still under 10 total brews so it's always a new batch for me. Yesterday when i brewed i had my bag sitting above the kettle draining as it was heating up. Since its on a pulley system and i don't have to hold it or anything i decided to drop it back down into the wort for a few minutes, it seemed to get me a couple more points but i also had a larger temp drop so i figured it didn't hurt anything since i was waiting on the wort to warm up anyways. First time doing this but i think I'll do it again.

 

[RM-MN]

It’s anecdotal evidence, but for me I see about a 5%-7% increase in efficiency by bringing the wort up to ~168F. It doesn’t seem like much so I can understand the hesitation. Heck I wonder the same thing.

When you don't already have full conversion at the end of the mash period the heating of the mash makes the alpha amylase work faster so you get closer to full conversion. The hotter mash also denatures the beta amylase quickly so you get a more dextrinous wort as the beta amylase isn't there to break down the dextrines.

 

[Shawn3997]

When you don't already have full conversion at the end of the mash period the heating of the mash makes the alpha amylase work faster so you get closer to full conversion. The hotter mash also denatures the beta amylase quickly so you get a more dextrinous wort as the beta amylase isn't there to break down the dextrines.

Don't you accomplish the same thing though with a step at 162F-ish?

 

[RM-MN]

Yes, except that the beta amylase doesn't get denatured as quickly.

 

[jam095]

Time to brew, so I don't have time to respond in depth, but I don't quite buy the "viscosity" thing. Seems to me all you're doing when you add water for the mash out is diluting it. How much more viscous is 170 degree water/sugar than 155? Not a lot, and hard to imagine it makes much if any difference.

Anyway, off to brew. Good conversation, this--and maybe our politicians could take a lesson from people disagreeing without having to be disagreeable.

For BIAB, you don’t add any water to mash out.. you just add heat

 

[4of7]

Time to brew, so I don't have time to respond in depth, but I don't quite buy the "viscosity" thing. Seems to me all you're doing when you add water for the mash out is diluting it. How much more viscous is 170 degree water/sugar than 155? Not a lot, and hard to imagine it makes much if any difference.

Anyway, off to brew. Good conversation, this--and maybe our politicians could take a lesson from people disagreeing without having to be disagreeable.

I just bring the mash up to 170 through the recirculation method without adding additional water