Going All Grain Part 2: Using the Mash-tun

My first post of going all-grain outlined the process of building your newest piece of brewing equipment, the mash-tun. For the second part of this series I will outline the basics of how I setup to mash, calculate strike water temps and combining it all together to start mashing.

For this process we’ll need to start with a basic recipe. Lets look at the grist (grain bill) for my ESB:

14.5 lbs English 2-row Pale
1.0 lbs Crystal Malt 40°L
1.0 lbs Victory® Malt
3.0 oz Chocolate Malt

In this recipe, there is 16.8 pounds of grain to be mashed. I crush them all with my corona mill and store it in a large bin until I am ready. Typically, I crush my grain no earlier than the night before. Too much earlier and that may promote staling of the grains once the husk has been broken open during the crush. Now that we have a recipe and a bin full of crushed grain we need to think about amounts of water and the balance between mash temp and strike temp.

Mash Temperatures:

Mash temp is the final temperature you want the final mash to be at once all your water and grains are combined. An average middle of the road mash temp is 154F. When first getting accustomed to the mashing process and how your individual equipment works I strongly recommend dong all your mashes at this temp. Once you get comfortable with being able to hit that mash temp each time you brew, then it becomes easier to adjust it to suit your needs, depending on style and tastes. If you brew a Stout then a pilsner then a brown ale then a Tripel, and try to adjust your mash temp every time I think that leads to a lot of missed mash temps, and a lot of discouraging results. So trust me on this one. Plan your first three all-grain brews to either be the same beer or styles that will let you get away with the same 154F mash temp (i.e. ESB, IPA, Browns, APA, bitters etc).

I like to mash with a thickness of 1qt/lb. I have seen a lot of recipes, sites and books that use 1.25qt/lb as the average thickness. I find that for my cooler set up, 1:1 ratio give me a loose oatmeal like mash, which is what you want. Also, if I miss my mash temp I can always add some more water that brings the mash to 1.25:1, and keeps me from thinning the mash too much.

There are many calculators on line to calculate the temp of your strike water. Strike water refers to the temperature that you need to heat up the water above the mash temp in order to achieve the desired mash temp. I use this site from the Green Bay Rackers. You need to know what the temperature of your grain is (generally the ambient temp of your storage location). Just fill in the weight of the grain, the thickness and temp of the grain; the calculator does the rest.

In my example recipe at 1:1 ratio, 16.8 lbs of grain would call for 16.8 quarts of water or 4.2 gallons. In my process, I would measure out 4.5 gallons and start heating it up on my burner. I keep a thermometer in the water and check it regularly. I stir the water I get close to strike temp to be sure its consistent throughout the water.

Combining water and grain:

After the water is at strike temp, I use a one-gallon pitcher to start transferring the hot water into the empty mash tun (with the SS hose-braid already installed). After the first couple gallons are in, I then lift up the pot heating the water and dump the rest in. Once all the water is in I quickly start adding grain. I add about a third of it at a time, and stir well to prevent little dough balls of grain from developing. I try to move quickly so I don’t loose too much of the heat from the water. As I am stirring in that last third of grain, I will put one of my thermometers in the mash. After closing the lid, I wait 5 minutes or so to let the temperature equilibrate, then I open the tun and check the status.

If my mash temp is within 1-2 degrees of what I wanted I don’t try to change it. It seems like too much effort. I do however usually put one gallon of water on the burner to start boiling. That way I have 1 gallon of super hot water that I can add if my mash temp was 5 degrees or so less than I wanted. A quick small infusion will usually get me back to where I want it. As small infusion of cold water works too, as long as the water is fairly cold, so as to not need to overly thin the mash.

I then close the lid, and cover it with a few towels. The lack of insulation in the lid can allow a lot of heat to escape out the top even with the lid closed. I find that two old towels folded in half do a great job insulating the lid.

Then the mash sits for 60 minutes until it time to sparge.

To get the sweet wort out of the tun I use a batch sparging approach. I find this is relatively quick and I get pretty good efficiency (generally >70%).

In part three of this series, I’ll cover clarifying the wort with recirculation, draining the tun and adding sparge water. Also, I’ll show how I monitor the progress of extraction by using a refractometer to get quick and easy readings while I sparge.