Moving from extract brewing to all-grain can be like earning a badge of honor in home brewing. Many who started extract brewing have never seen the need to expand into more complicated or exacting recipes, nor have needed that jump to be fair, as many award winning brews are extract-based (or at least partial mashed or include steeping grains). Many of those who have moved, however, have done so more simply through brew in a bag (BIAB). While this method solves most of the nagging issues of extract such as grain availability, fermentability of the wort, and lighter beer color, there is still much to be had by improving the mash in multiple vessel brewing.
The remaining benefits of moving to multiple vessel brewing is what this article is all about. Specifically, honing in on the finer aspects of the mash, since once the wort hits the boiler, everything else is the same as extract brewing (for the most part). What I have attempted to do over my years of continual equipment improvement and control is earn that badge of repeatability (to keep the metaphor going): the ability to take a recipe that I like and change it ever so slightly to suit my tastes, and remove all other variables in order to focus on that change. This is a large undertaking, since the variables include everything from grain/hops production and specs all the way through carbonating and serving. However, the bulk of the variable flavor impact occur with fermentation, and the first step of that is micro-controlling the mash with a dedicated mash/lauter tun (MLT). So let’s start there.
Maintaining mash temp is important with a traditional mash tun, as well as BIAB
Heat the strike water, dip the bag of grains in, stir it around on low heat, and use a horse with a pulley and hoist the bag out. Pretty easy to make a good beer through BIAB, but there are a lot of knobs you can turn to make a good beer great. As I mentioned above, controlling the fermentability of the wort can have a huge impact on the flavor and mouthfeel of the beer. Fermentability can also be defined as controlling which, and to what extent, the enzymes in the grain works.
Let’s say you want to hit a mash temperature of 155°F for 60 minutes, and immediately stop enzyme activity for beer with a fairly heavy residual sweetness (or maltiness, or however the recipe and your taste buds define that impact). That means any slip into lower temps will drive more beta-amylase activity, producing a more fermentable and possibly drier beer. What that means for BIAB brewers is constant stirring and a close eye on the heat source. Stopping the enzymatic activity is as simple as increasing the heat (being careful not to scorch the grain or burn a hole in the bag) to 170°F, removing the bag, and starting the boil.
An improvement on this system in a dedicated MLT would actually be quite minimal. Using an MLT has the added benefits of possibly using a more insulating material and not worrying about scorched grains, but the actual process of mashing in, stirring, checking temperature and (with the right accessories) maintaining the temp and mashing out remain unchanged. The real benefits of a dedicated mash system are realized in ancillary steps.
On a commercial scale, the process of rinsing the grains is where much of the extract efficiency and lowering the cost of goods comes into play. While this is less of a factor for homebrewers, as the loss of extract in the grain through BIAB accounts maybe for a pound or two of grain, sparging the grain starts the march towards beer clarity and controlled pH, among others.
In BIAB, the sparge is typically as simple as moving the bag to another heated vessel of a small amount of water at an elevated temperature, sloshing it around and pulling it out. That rinse water is then added to the boil kettle. While many methods exist for achieving this process, it is essentially a batch sparge, or further dilution of extract in the grain.
Fly Sparging the mash
With a dedicated mash system, a number of sparges can easily be done in the same vessel using a false bottom, or one could fly sparge to squeeze a little more juice out of the grain. Either way, this separation of the grains and the boil kettle gives the brewer the ability to drain a very clear wort into the kettle through a vorlauf. Either by recirculating the mash with a pump or simply taking a quart at a time out and pouring it back on the top of the grain, the grain bed acts as a sand filter when it comes time to run it out and lauter, thus removing fine particles that would otherwise make it into the kettle during BIAB.
While there is certainly a lot of controversy on whether this is completely necessary both in the commercial and homebrew communities, it is yet another knob you can turn to tune up the brewing process. Removal of fine particles and possibly unconverted complex starches may have the benefit of decreasing astringent tannin extraction in the wort as well as clarifying the final beer. Only you can tell if it makes a difference in your beers.
Another benefit of separating the lauter of the grains from the kettle is that you can fine tune the extract efficiency through a number of rinsing processes. Depending on the shape and size of the false bottom or screen in the mash tun in addition to the sparge method (batch or fly sparge), the rinse process can be carefully tweaked to move a typical 70% BIAB efficiency up to the high 80’s. Not a requirement by far, nor will it significantly impact the beer quality, but it’s still fun to push the limits of your gear isn’t it?
One major downside, however, to the fly sparge process in a dedicated system is that it takes a good while to do it right. A typical 5 gallon mash could take upwards of 45 minutes just to get the wort in the kettle. Of course the kettle can be heating all this time so that the boil is starting just as the final runnings are coming off, but it is still something to consider.
Possibly one of the most important advantages of moving to a dedicated mash/lauter system, and I felt it needed its own section, is control over the mash pH. It’s not a straight forward process, and there are various levels of commitment in controlling the contents of your brewing water. It would therefore be irresponsible to dive into the complex specifics in this article. There are various sources out there for calculating mineral additions, etc., such as Bru’n Water, Brewer’s Friend, EZ Water, as well as some brewing software that has built in calculators that can get you started. What should be stated, however, is what benefit a dedicated mash system would have in the water chemistry process.
There are 2 main aspects of controlling brewing water chemistry: through addition (or removal) of salts, and adjustment of the water pH. With a mash system, you can split the salt that you normally might add to the boil kettle into the mash tun and hot liquor tun. This is important because as the mash grains are rinsed, the pH and mineral contents also change. If sparging with a lower pH than typical 7.5, you can maintain a lower wort pH for lighter beers, for example, reducing tannin extraction and astringency. You can also add back salts and necessary minerals to the sparge water that the grains would absorb in the mash, thus maintaining a calculated mineral profile in the wort.
In my opinion, by far the greatest impact on the quality of the beer goes to a healthy fermentation, and the wort chemistry is a large chunk of that (with fermentation temperature taking up another chunk). Being able to tune certain aspects of the brewing process so that the yeast have the best chance to create the flavor profile you are looking for is how good beers are made into great ones.
For those who are looking to build a little complexity and knobs to their brewing day, I thought it would be helpful to add a chart to help visualize the steps in creating wort by BIAB and through a dedicated mash system. Given the fact there are so many kinds of builds, I will make the comparison with one system, a HERMS, or heat exchange recirculating mash system (which can essentially be considered a RIMS system for this example).
A move to a larger and more complex system always results in the creation of new issues you never had with a simpler process. While not every brewer will ever need to leave BIAB due to budget, time, or space constraints (or needs, for that matter), those who do should enter this world with the caveat that you may indeed lower the quality of the beer before it gets better, or until you get your new system down. That being said, I’ve never been happier with the beers I make with my all-grain system. I can look at my control box and know exactly what temperature things are at, control flow rates, chemistry, etc., and never have a doubt of what’s going into the boil kettle. With all the things that can go wrong from milling to pouring, this little bit of insurance makes me feel good. Almost as good as pouring a fresh glass.
Good luck!
The remaining benefits of moving to multiple vessel brewing is what this article is all about. Specifically, honing in on the finer aspects of the mash, since once the wort hits the boiler, everything else is the same as extract brewing (for the most part). What I have attempted to do over my years of continual equipment improvement and control is earn that badge of repeatability (to keep the metaphor going): the ability to take a recipe that I like and change it ever so slightly to suit my tastes, and remove all other variables in order to focus on that change. This is a large undertaking, since the variables include everything from grain/hops production and specs all the way through carbonating and serving. However, the bulk of the variable flavor impact occur with fermentation, and the first step of that is micro-controlling the mash with a dedicated mash/lauter tun (MLT). So let’s start there.
Hitting and Maintaining Mash Temp
Maintaining mash temp is important with a traditional mash tun, as well as BIABHeat the strike water, dip the bag of grains in, stir it around on low heat, and use a horse with a pulley and hoist the bag out. Pretty easy to make a good beer through BIAB, but there are a lot of knobs you can turn to make a good beer great. As I mentioned above, controlling the fermentability of the wort can have a huge impact on the flavor and mouthfeel of the beer. Fermentability can also be defined as controlling which, and to what extent, the enzymes in the grain works.
Let’s say you want to hit a mash temperature of 155°F for 60 minutes, and immediately stop enzyme activity for beer with a fairly heavy residual sweetness (or maltiness, or however the recipe and your taste buds define that impact). That means any slip into lower temps will drive more beta-amylase activity, producing a more fermentable and possibly drier beer. What that means for BIAB brewers is constant stirring and a close eye on the heat source. Stopping the enzymatic activity is as simple as increasing the heat (being careful not to scorch the grain or burn a hole in the bag) to 170°F, removing the bag, and starting the boil.
An improvement on this system in a dedicated MLT would actually be quite minimal. Using an MLT has the added benefits of possibly using a more insulating material and not worrying about scorched grains, but the actual process of mashing in, stirring, checking temperature and (with the right accessories) maintaining the temp and mashing out remain unchanged. The real benefits of a dedicated mash system are realized in ancillary steps.
The Sparge
On a commercial scale, the process of rinsing the grains is where much of the extract efficiency and lowering the cost of goods comes into play. While this is less of a factor for homebrewers, as the loss of extract in the grain through BIAB accounts maybe for a pound or two of grain, sparging the grain starts the march towards beer clarity and controlled pH, among others.
In BIAB, the sparge is typically as simple as moving the bag to another heated vessel of a small amount of water at an elevated temperature, sloshing it around and pulling it out. That rinse water is then added to the boil kettle. While many methods exist for achieving this process, it is essentially a batch sparge, or further dilution of extract in the grain.
Fly Sparging the mashWith a dedicated mash system, a number of sparges can easily be done in the same vessel using a false bottom, or one could fly sparge to squeeze a little more juice out of the grain. Either way, this separation of the grains and the boil kettle gives the brewer the ability to drain a very clear wort into the kettle through a vorlauf. Either by recirculating the mash with a pump or simply taking a quart at a time out and pouring it back on the top of the grain, the grain bed acts as a sand filter when it comes time to run it out and lauter, thus removing fine particles that would otherwise make it into the kettle during BIAB.
While there is certainly a lot of controversy on whether this is completely necessary both in the commercial and homebrew communities, it is yet another knob you can turn to tune up the brewing process. Removal of fine particles and possibly unconverted complex starches may have the benefit of decreasing astringent tannin extraction in the wort as well as clarifying the final beer. Only you can tell if it makes a difference in your beers.
Another benefit of separating the lauter of the grains from the kettle is that you can fine tune the extract efficiency through a number of rinsing processes. Depending on the shape and size of the false bottom or screen in the mash tun in addition to the sparge method (batch or fly sparge), the rinse process can be carefully tweaked to move a typical 70% BIAB efficiency up to the high 80’s. Not a requirement by far, nor will it significantly impact the beer quality, but it’s still fun to push the limits of your gear isn’t it?
One major downside, however, to the fly sparge process in a dedicated system is that it takes a good while to do it right. A typical 5 gallon mash could take upwards of 45 minutes just to get the wort in the kettle. Of course the kettle can be heating all this time so that the boil is starting just as the final runnings are coming off, but it is still something to consider.
Mash pH
Possibly one of the most important advantages of moving to a dedicated mash/lauter system, and I felt it needed its own section, is control over the mash pH. It’s not a straight forward process, and there are various levels of commitment in controlling the contents of your brewing water. It would therefore be irresponsible to dive into the complex specifics in this article. There are various sources out there for calculating mineral additions, etc., such as Bru’n Water, Brewer’s Friend, EZ Water, as well as some brewing software that has built in calculators that can get you started. What should be stated, however, is what benefit a dedicated mash system would have in the water chemistry process.
There are 2 main aspects of controlling brewing water chemistry: through addition (or removal) of salts, and adjustment of the water pH. With a mash system, you can split the salt that you normally might add to the boil kettle into the mash tun and hot liquor tun. This is important because as the mash grains are rinsed, the pH and mineral contents also change. If sparging with a lower pH than typical 7.5, you can maintain a lower wort pH for lighter beers, for example, reducing tannin extraction and astringency. You can also add back salts and necessary minerals to the sparge water that the grains would absorb in the mash, thus maintaining a calculated mineral profile in the wort.
In my opinion, by far the greatest impact on the quality of the beer goes to a healthy fermentation, and the wort chemistry is a large chunk of that (with fermentation temperature taking up another chunk). Being able to tune certain aspects of the brewing process so that the yeast have the best chance to create the flavor profile you are looking for is how good beers are made into great ones.
The Dedicated Mash System Process
For those who are looking to build a little complexity and knobs to their brewing day, I thought it would be helpful to add a chart to help visualize the steps in creating wort by BIAB and through a dedicated mash system. Given the fact there are so many kinds of builds, I will make the comparison with one system, a HERMS, or heat exchange recirculating mash system (which can essentially be considered a RIMS system for this example).
A Final Word
A move to a larger and more complex system always results in the creation of new issues you never had with a simpler process. While not every brewer will ever need to leave BIAB due to budget, time, or space constraints (or needs, for that matter), those who do should enter this world with the caveat that you may indeed lower the quality of the beer before it gets better, or until you get your new system down. That being said, I’ve never been happier with the beers I make with my all-grain system. I can look at my control box and know exactly what temperature things are at, control flow rates, chemistry, etc., and never have a doubt of what’s going into the boil kettle. With all the things that can go wrong from milling to pouring, this little bit of insurance makes me feel good. Almost as good as pouring a fresh glass.
Good luck!
