To do or Not to do, B.I.A.B. Mash Out

[FatherSonBrew]

We come to believe, because of Pre-Boil SG being off occasionally, that we may be leaving some sweet wort behind the Mash process when a Mash out is not implemented. While shutting down enzyme activity is not a huge concern in B.I.A.B. Process (we think) the additional heat and overall longer Mash process may be creating an environment for more wort sugars to be extracted. We seem to have better results with a Mash Out. What is the common practice. Any recommendations?

 

[Oginme]

When I was doing BIAB on my stove top, I never did a mash out. I would pull the bag and immediately start the temperature rising towards boiling. It accomplishes the same thing.

While raising the bag at mash out temperatures does lower the viscosity of the wort slightly, the ability on a home brew level to realize much improvement in volume recovered is very questionable.

If you have sufficiently converted the starches into sugars, the one thing you should not see is increased specific gravity of the wort. The additional wort you get out will have the same specific gravity (when measured at room temperature). The same holds true for squeezing the bag to get extra wort out. I have tested both the mash out and the squeezing exhaustively over the many brews I have made to demonstrate to myself that I am achieving full conversion.

If you are seeing additional gravity increase due to the mash out or squeezing the bag, then you will gain just as much or more from extending the mash time to allow for full conversion of the starches,

 

[BOB357]

I'm with Oginme here.
Try doing an iodine test to check for complete conversion. If it indicates incomplete, extend the mash. Unless you're brewing an adjunct heavy beer or failing to maintain a reasonable temperature throughout the grain bed, there's no reason you shouldn't have complete conversion in 60 minutes or less. I'm assuming your water chemistry is within reasonable limits.

 

[FatherSonBrew]

I posted the question for I was on the fence on this issue. It just seems that if the bag is 20 degrees hotter that when lifted it would release more sugars that cling to matter. Volume is far more than what is just squeezed. Volume is everything soaked into and around the grains as the bag is lifted. I also visualize the enzymes with sugar cane stocks in their mouths and they drop them when the extra heat is applied. A cartoon like visualization, probably really irrelevant, as well. This may just boiled down to what feels good for the individual. Possibly nothing gained and nothing lost.
Thanks for the feedback!

 

[Kevin58]

A mash out isn't done to get more sugar from the mash. A mash out it done to stop the sugar conversion. It is primarily done by commercial brewers who are concerned with consistency. The beer they make must be have a gravity of x.xxxx every time. Not x.xxxx+1 today and x.xxxx-2 tomorrow. So when they hit the gravity they require they denature the enzymes with a mash out.

Home brewers often convince themselves they need to adopt the same practices as the commercial brewers. After all, if they are doing it, it must be the best way. But like many practices used in the commercial brewery, mash outs just are not necessary on the homebrew level. There are some pracitces you are just better off wiping from your mind never again to be concerned with. For me, one of these things is the mash out.

 

[BeerSmith]

Actually the idea of stopping conversion with a mash out turns out to be not quite true. Alpha and beta amylase enzymes have an ideal temperature range but they continue to work, albeit much slower, even at higher or lower temperatures. So while we once believed we could "halt" these enzymes with a mash out they really are not halted completely but just slowed to a snails pace.

Most modern references say that the main purpose of the mash-out is to lower viscosity which can improve extraction a bit. It also can also help to reduce the chance of a stuck mash when working with large portions of non-barley adjuncts.

 

[Finn Berger]

You may actually be getting a slightly higher gravity when doing a mash-out. The reason is that you will gelatinize more starch, which may then be converted to sugar, as you raise the temperature. You do not start gelatinizing the smaller starch particles in barley, which make up about 10% of the total, until you reach 70 degrees C/158 F, and you will not gelatinize all the starch until you reach 94C/201F (source is Kai Troester). And as alpha is still active at mash-out temperature there ought to be an effect. It is probably small, though. And it will be totally meaningless anyhow, because it will be mostly dextrins, and those will have no effect on any of the qualities of the beer.

I don't think any beta will survive into the mash-out. It is denatured at temperatures above 65C/150F, and though it doesn't happen instantly, it won't last long above that limit. It does work faster when it gets warmer, though, so a single infusion mash at 67C/154F will still get you a very fermentable wort, not much lower than at 65/150, which is the ideal (Source is table in Palmer's How to Brew.)It is also generally less hardy than alpha.

I never do a mash-out, but I do normally use a long step at 72C/162F, which according to Troester (who refers to Narziss, if I remember correctly. Or was it Kunze?) produces glycoproteins, which give you a better mouthfeel, and better foam stability. I do think it works. The effect isn't dramatic, but still worth the effort, I think. And so that is perhaps an alternative to the old mash-out? (I think it gives a couple of gravity points, but those are, as I said earlier, meaningless points.)

As for the effect of the lower viscosity, I can't say. I've sparged with water at 30C/87F, and couldn't notice any diminshed efficiency, so my guess is that the effect is minmal at best.

 

[MaxStout]

I do BIAB for its simplicity, realizing that I may be leaving a little wort behind. I had tried the "pour-over" sparge a few times to glean a little more, but noticed more astringency in the final beers. Instead I simply hoist out the bag and let it drip into the kettle while I bring the wort to a boil. I give the bag a few squeezes, but nothing beyond that.

 

[Finn Berger]

I do BIAB for its simplicity, realizing that I may be leaving a little wort behind. I had tried the "pour-over" sparge a few times to glean a little more, but noticed more astringency in the final beers. Instead I simply hoist out the bag and let it drip into the kettle while I bring the wort to a boil. I give the bag a few squeezes, but nothing beyond that.

hmm - the astringency seems strange. The only thing I can think of is that you sparge with water that sends the pH up too high. If your water has much alkalinity, your mash pH may already be fairly high - at least when brewing beers with little or no dark malts - and so the alkaline sparge water will tip you over the limit.

Something special must be happening, because people have been using that technique for a long time, and I have never heard that it should cause astringency.

Do you have a water report?

 

[MaxStout]

I build the water from RO + CaCl2 & CaSO4

 

[Finn Berger]

I build the water from RO + CaCl2 & CaSO4

Then my pretty theory is ruined. Not much alkalinity in that water. And if you brew maximum stout with it, without further adjustment, the pH will fall through the floor and down into the basement - but that doesn't produce astringency, as far as I know.

Anyways, you're probably into water adjustment since you're using RO water. So then I don't have any suggestions as to why you should get astringency from sparging.

 

[MaxStout]

I should mention that the astringency diminished somewhat in beers I brewed after I stopped rinsing grains. So, a correlation, but not necessarily causation. I eliminated one variable and noticed improvement. Some of my beers still have a bit of an astringent twang, though not overly so--not like before. I'm trying to root out the culprits--work on my crush, add roasted grains late in the mash, and reduce oxygen uptake wherever I can.

It's an iterative process.

 

[Finn Berger]

I should mention that the astringency diminished somewhat in beers I brewed after I stopped rinsing grains. So, a correlation, but not necessarily causation. I eliminated one variable and noticed improvement. Some of my beers still have a bit of an astringent twang, though not overly so--not like before. I'm trying to root out the culprits--work on my crush, add roasted grains late in the mash, and reduce oxygen uptake wherever I can.

It's an iterative process.

Having a problem you don't know the cause of is hell. Mine is sulphur dioxide (H2S), especially in pilsners. I know it's part of the game, but it's supposed to disappear as the yeast produces CO2 which will help take it out. But it's not quite that easy in my brewery. And I have really tried all cures available - or so I think.

Well, that has got nothing to do with BIAB. Off topic. Just a declaration of sympathy.

 

[FatherSonBrew]

Astringency after B.I.AB. strikeout rinse seems odd, unless darker grains involved. I would wonder about the bag itself. May fad away over time?
Pilsners are fun and delicious. Most common brew consumed. I have heard and read about Pilner malts requiring longer mash times and hotter more vigorous boils. But here is another debate. I am personally struggling with hotter boils for I am seeing more multiple late boil breaks after initiating the rapid boils. Also, I was surprised at how the evaporation rate was increased and effected equipment profile water loss volume. Almost seems like boil rate should be part of equipment profile, for I am leaning on using different boil rates for different beer styles.
Sorry for the late response. My computer died when the hurricane IAN passed through. Resurrecting my personal BeerSmith data was not as easy a task as I thought it would be. Did not realize how data was stored by default in windows program directory (hidden) and my import from aged export failed on first try, which also though me off. Another example of where tech is using us, instead of us using tech. I used to love that old command line.

 

[BOB357]

Sorry for the late response. Boil off is part of the equipment profile, though not expressed as a rate. There are too many variables to apply a rate universally. Specifying your boil off volume at a given duration and checking the "Use boil off as an hourly rate" box is about as good as it gets.