Anything wrong with full volume mash?

[petrolSpice]

On all of my BIAB brews I've done a full volume mash, as in I mash my grains in the preboil volume of water, no water additions or sparging. I always read about mash thickness and realize mine is usually 2.5-3 quarts/lb, much higher/thinner than what seems to be the norm. But I figured thinner is better for efficiency.

Is this process okay, or am I causing some harm to be brew or efficiency?

 

[FatDragon]

Not a problem at all. Some of us get a little bit better efficiency (a few points, not necessarily worth getting worked up about) by reducing the mash volume and adding a sparge of the bag, but if you're happy and consistent where you're at, a full volume mash is a great way to simplify your brewday and still make great beer.

Brew on!

 

[RM-MN]

You may want to check the mash pH as with some water, that full volume can drive the pH rather high depending on the grain bill. I've made a low alcohol beer that had even higher water to grain ratio with no problems but I did add acid to the mash.

 

[ajdelange]

My concern would be with dilution of the enzymes relative to what would be found with a more normal water to grist ratio. I am not really concerned about efficiency. Do you want the cheapest beer or the best tasting? Were I you I would be experimenting to see what water to grain ratio gave me the best tasting beer - not which gave me the highest efficiency.

 

[Oginme]

I've found, from bouncing back and forth between traditional mash-tun and full volume BIAB that I get a slightly more fermentable wort with the full volume BIAB mash. Compared to my more traditional system, I need to up the mash temperature by a couple of degrees to match FG on the same recipe. I've never found the dilution of enzymes to be an issue, but then I haven't tried short cutting mash times to less than 60 minutes on either system. My efficiency is a bit better on the full volume BIAB, but then I grind slightly finer vs when I use my mash-tun setup. I do get a couple of points higher in mash efficiency when I do a batch sparge with the BIAB but I'm already in the upper 80's and it really does not present a significant gain. I do get more predictability in mash efficiency and end results with the full volume mash vs BIAB with batch sparge, but that may also be because I have not spent enough effort into pinning down my batch sparge BIAB process as tightly. In the end, I aim for repeatability and consistency.

 

[Brew_Meister_General]

On all of my BIAB brews I've done a full volume mash, as in I mash my grains in the preboil volume of water, no water additions or sparging. I always read about mash thickness and realize mine is usually 2.5-3 quarts/lb, much higher/thinner than what seems to be the norm. But I figured thinner is better for efficiency.

Is this process okay, or am I causing some harm to be brew or efficiency?

From the various sources I've looked at, a thinner mash leads to greater efficiency but only after the sparge, meaning the first runnings have a much lower gravity in comparison to a thick mash (1.25 qt/lb).

This suggests you can reduce the ratio to maybe even 1lb/qt or use the second runnings of a thin mash to make a low gravity beer (i.e. parti-gyle) or boil it down to make a mini-beer and maybe experiment with it.

I think I'll try that myself!

This is one home recipe that looked at the density of the mash:

 

[austin713]

nope. its what BIAB is meant for. as soon as you start sparging you might as well just mash in a mashtun.

 

[doug293cz]

On all of my BIAB brews I've done a full volume mash, as in I mash my grains in the preboil volume of water, no water additions or sparging. I always read about mash thickness and realize mine is usually 2.5-3 quarts/lb, much higher/thinner than what seems to be the norm. But I figured thinner is better for efficiency.

Is this process okay, or am I causing some harm to be brew or efficiency?

Mash efficiency is equal to conversion efficiency times lauter efficiency.

Thinner mashes have faster conversion rates, so can lead to higher conversion efficiency in cases where the mash time is not sufficient for 100% conversion (ref: http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness.) The higher rate of enzymatic action in thinner mashes also explains the higher wort fermentability with thinner mashes noted by @Oginme earlier in this thread.

A no sparge process will have about 8.4% +/- 0.6% lower lauter efficiency than a well conducted equal runnings volume single batch sparge (the most efficient single batch sparge), IF the grain absorption rate is the same for both cases. However if BIABing, you have the opportunity to reduce the grain absorption rate by extended draining and/or bag squeezing. Typical grain absorption rate for a traditional MLT is 0.12 gal/lb. For BIAB with moderate to aggressive squeezing, grain absorption rates vary from 0.06 to 0.08 gal/lb, and this makes a significant difference in lauter efficiency, as shown in the chart below:



Brew on

 

[treacheroustexan]

I'm going to start BIABing for 2.5 gallon batches. Doing my first tomorrow. I'd like to do full volume mashes as well. What's the best way to calculate how much water I will need for my full volume mash with absorbing the grain and what not? I figured I'l boil off .5gal/60min.

 

[Jimbodaman]

I'm going to start BIABing for 2.5 gallon batches. Doing my first tomorrow. I'd like to do full volume mashes as well. What's the best way to calculate how much water I will need for my full volume mash with absorbing the grain and what not? I figured I'l boil off .5gal/60min.

I just plug in all my recipe info to beersmith and just look on the volumes tab for total volume of water needed. That's how much water I use. I would suggest with full volume mashes to add ~2% acid malt for mash pH. This amount will likely have no impact on flavor and keeps my mash pH in check.

 

[treacheroustexan]

I just plug in all my recipe info to beersmith and just look on the volumes tab for total volume of water needed. That's how much water I use. I would suggest with full volume mashes to add ~2% acid malt for mash pH. This amount will likely have no impact on flavor and keeps my mash pH in check.

Been a while since I used BS since getting a grainfather. Does beersmith have a profile for 2.5 gal BIAB or do I need to make one? I'd check but I'm at work.

 

[doug293cz]

I'm going to start BIABing for 2.5 gallon batches. Doing my first tomorrow. I'd like to do full volume mashes as well. What's the best way to calculate how much water I will need for my full volume mash with absorbing the grain and what not? I figured I'l boil off .5gal/60min.

http://pricelessbrewing.github.io/BiabCalc/ Highly recommended.

Brew on

 

[treacheroustexan]

Thanks all. Does 4.65 gallons seem reasonable for a full volume mash? About 6.4# of grain.

 

[pricelessbrewing]

Depends on your intended batch size, and boil off rate.

 

[jason.mundy]

Thanks all. Does 4.65 gallons seem reasonable for a full volume mash? About 6.4# of grain.

For a 2.5 gallon batch size and 6.4# of malt.

2.5 gallons batch size + 1 gallon boil off + .08G/# * 6.4# = 4 gallons

6.4# * 36 points per pound per gallon * .8 efficiency / 2.5 gallons = 1.074 OG