For anyone who is interested in brewing an all grain homebrew batch of Pliny the Elder, I have posted the recipe that I brew. It is a great recipe and tribute to one of the most famous and hard to get Double IPA’s out there. In fact it is so hop packed that this home brewing recipe even calls for a hop addition to the mash!
For those of you who are not familiar with RIMS, it stands for Recirculating Infusion Mash System. Basically it is a method for regulating the temperature of your mash tun during the mashing process when the grain starches are converted to sugars. The mash temperature is critical when brewing a beer and a swing of just a few degrees can have a dramatic impact on your finished beer. For instance, a mash temperature of 146F to 150F will create very simple sugars that are easy for yeast strains to convert into alcohol, providing you with a beer that has a dry finish. While a mash temperature of 154F to 158F will create a good deal of complex sugars that the yeast can not digest which makes for a very full bodied beer that will be lower in alcohol.
If you conduct your mash in metal kettles such as the stainless steel Blichmann 20 gallon kettles that I use, you will find that your kettles will shed a good deal of heat during the mash process. In order to maintain a proper mash conversion you will need to either heat the kettle or the fluid inside of it. The problem with adding direct heat to your mash tun kettle is that you risk scorching your grain bed or wort and may also have a large temperature variance at the bottle of the mash tun and the top of it. If you are going to apply direct heat, it is important that you are recirculating your wort with a pump to help minimize those issues. Another potential problem with direct heat is that it can be difficult to monitor and control with out the use of a temperature controller and means for regulating the heat source; if you are not careful your temperature can swing by 5 degrees very quickly.
For the reasons I stated above, I recently started work on a RIMS (Recirculating Infusion Mash System) to help me properly maintain my mash temperature. I am still conducting tests with it but plan on brewing my first test batch of beer this weekend and am optimistic that it will work out well and help me brew the best beer possible. The system is rather simple. I am constantly recirculating the wort in my mash tun via a march pump. The wort flows into a stainless steel chamber where I have an electric stainless steel heating element at the point of entry. At the opposite end of the chamber is a thermowell that is connected to a Ranco digital temperature controller. If the Ranco temperature controller detects that the temperature of the wort has fallen below my target temperature, then it activates the low watt electric heating element until the target temperature is once again reached and then shuts the element off. The wort flows out of the chamber and back into my mash tun via my MoreBeer Ultimate Sparge Arm. Instead of obsessing over my mash temp and constantly fiddling with my burner and pumps, I can kick back, toss the football around with a friend and enjoy a cold beer until my timer goes off! It should make for a more controlled mash and less stressful brew day if all goes well. Once the design is fully tested I will submit another blog entry with more details on how to build one of your own. In the meantime, you can find Ranch temperature controllers and the MoreBeer Ultimate Sparge Arm here.
Wort is the name given to the sugar rich liquid that is extracted from the mash prior to fermentation. Prior to the boil, when the hops have not yet bittered the wort, it is known as sweet wort. After the boil but prior to fermentation, it is known as bitter wort since the beta acids from the hops have imparted a bitter flavor upon it.
A photo of sweet wort being transferred from the mash tun to the boil kettle after sparging had completed:
Wort (unfermented beer) being transferred after sparging.
Step infusion is a beer mashing method where differing temperatures and quantities of water are infused in the mash tun from the hot liquor tank at specific intervals or steps in the mash process to control sugar conversion and extraction.
Recirculation is the process of pulling the wort from the base of the mash tun or lauter tun and recirculating it back on to the top of the grain bed. Recirculation typically occurs after the end of the mashing process. As the hot wort is recirculated through the grain bed of the mash, the grains act as a particle filter clearing the wort. As the wort is recirculating, it becomes cleaner and less turbid until finally it is clear and ready to be passed to the boiling vessel.
A pump is typically used to recirculate the wort at a steady and controlled pace. In the case where a home brewer does not have a pump available, the wort may be drawn into a container and slowly poured back on top of the grain bed. The process can be repeated until the wort has become clear. Additionally, rice hulls may be added to a mash as a means of boosting the filtration capability of the grain bed.
A wide selection of home brewing recirculation pumps can be found here:
Sparging is a brewing process that involves passing heated water through the grain bed of a mash to extract sugars from the crushed grains and adjuncts. Sparging is typically conducted at approximately 167° F to 170° F; if the temperature exceeds 170° F, the brewer risks extracting excessive amounts of tannins from the grains. If the temperature is too low, then the sparge will be ineffective at liquefying the remaining converted sugars from the grains. While the sparge water passes from the hot liquor tank to the mash tun, or lauter tun, via a sparge arm, the extracted sugars and water are being drained from the base of the vessel and relocated to the boil kettle in preparation for to upcoming boil.
This mash is being sparged at 168° F, while the beer is being transferred from the false bottom at the base of the mash tun over to the boil kettle.
Sparging in the mash tun, while wort is transferred to the boil kettle.
Saccharification in very basic terms is the conversion of starches to sugars. When it comes to all grain brewing, saccharification is a critical conversion process that occurs during mashing. As the mash tun’s temperature is increased to a range of 120° F to 158° F, the diastatic enzymes of the malted grains begin to activate and break the starches of the grains and adjuncts into sugars. The alpha amylase enzymes break apart complex starches into sugars that the beta amylase enzymes break apart even further into easy-to-ferment maltose sugar.
Precision is critical when it comes to the temperature of a mash and 10 degrees makes a massive difference. Beta amylase is more temperature dependent than alpha amylase, and when the temperature in the mash begins to rise above 158° F, the beta amylase is no longer capable of breaking apart the more complex sugar chains into maltose. So if your target mash temp is 152° F and you instead conduct your mash at 162° F, you will be left with a massive amount of unfermentable sugars in your finished beer, and it will have a fuller body and overly sweet finish.
Beta amylase thrives in a temperature range of 140° F to 150° F, so if your target mash temp was 152° F and you conducted your mash at 142° F, you would end up with a beer with a very thin body and dry finish due to a deficiency of unfermentable sugars. This is the reason why the typical mash saccharification rest temperature is in a range of 152° F to 154° F; it provides a good temperature compromise for both alpha amylase and beta amylase to carry out their required starch and sugar conversion processes.
Mashing is the process of mixing and infusing crushed malts, unmalted grains, and adjuncts with hot water from the hot liquor tank. As the grains and adjuncts mix with the hot water at specific temperatures, enzymes from the malt activate and convert the starches into sugars. At the same time that the starches are being converted to sugars, color is also being extracted from the grains, which is the primary determining factor of the beer’s final color. The mashing process takes place in a brewing vessel called a mash tun.
Below is a photo of crushed grain being stirred in the mash tun during the mashing process.
The mash is water-saturated crushed malts, unmalted grains, and adjuncts that are present in the mash tun when the mashing occurs. During the mashing process, the starches will be broken down into sugars so they can be fermented by the yeast and converted into alcohol.
The mash for an American Wheat Hefeweizen towards the end of the mashing.
Infusion mashing is the process of regulating mash temperature by injecting heated water from the hot liquor tank into the mash tun at specific times.
When conducting a step infusion mash, differing temperatures and quantities of water are infused in the mash tun from the hot liquor tank at specific intervals or steps in the mash process to control sugar conversion and extraction.
When conducting a single infusion mash, the room temperature of the grains is compared with the desired mashing temperature and mash water volume. The hot liquor tank is then preheated to the appropriate temperature and the mash water is infused with the grains all at one time. The mash is maintained at a constant temperature until the mash out or sparging sequence begins.
RIMS or the recirculating infusion mash system is a mash infusion system that either utilizes a pump to recirculate the fluid in the mash over a secondary heat source (outside of the mash tun) to maintain the mash temperature, or constantly recirculates the mash onto itself while direct heat is applied to the mash tun to regulate temperature. The fluid is pumped at a rapid enough pace to keep the temperature of the mash at an equilibrium and prevents the wort from being scorched or overheated.
A HERMS or heat exchanged recirculating mash system is a mash recirculation system that regulates mash temperature by pumping the wort from the mash tun through a heat exchanging tube, coil inside of the hot liquor tank, or a secondary heating tank. The wort then flows back into the mash tun to maintain the mash temp without applying direct heat to the mash tun.