Cooked rye mash

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Uncle Jesse's : How I do a cooked rye mash

First, get yourself a Big Ole Pot (BOP):

Big ole pot.jpg

100 liter capacity as you can see.

Next, make sure you have a nice screen to use as a filter. Yes, I'm aware it could be a bit cleaner:


Here's a photo with the screen in place:

Screen in place.jpg

Make sure your pot has a lid otherwise you waste a lot of energy when heating your water:

Pot with lid.jpg

Next, I fill my grain mill with five lbs of malted rye. This stuff is no fun to mill as it takes quite a bit more effort than 2-row. This is a 10 gallon mash so I have to mill 20 lbs of malted rye. My mill holds 5 lbs at a time.

Note: use of dog with demonic green eyes is completely optional. He's a complete ham for the camera. I should figure out a way to hook a treadmill to this apparatus so he can do the work:

Grain mill.jpg

I fill the BOP with 6 gallons of water and bring it to a hard boil. The pot starts out clean but this kills any residual nastiness which I missed. Once it is at a hard boil, I add 6 gallons of room temperature water. Doing this to this particular mash brought the water temp down to 135 F so I had to warm it up to 170 F which is where I like to start.

After the water hits 170 F, I turn off the heat and use my Big Ole Spoon (BOS) to stir in my cracked rye:

Rye mash.jpg

For this particular mash, adding the grains brought my temps down to 151 F. A few degrees warmer than I prefer, but close enough so I covered the pot and let it sit. This pot was outdoor so I knew it would cool down rather quickly. I didn't want to adjust my temps down at all since they were in an acceptable range.

Cover your heated mash and let sit for an hour, stirring every 10 or 15 mins. A few times during the mash I like to take a few quarts from the bottom spigot and add it back to the top of the mash tun to add a bit of circulation since distillers worts are not sparged.

It is useful to do an iodine starch conversion test to check the progress of your mash. To do this you simply take a square Herradura shot glass (other types may work as well) and siphon off a bit of your wort:

Wort sample.jpg

Add a few drops of iodine and check to see if the color turns purple:

Iodine before conversion.jpg

This sample was taken 15 minutes after the mash-in started. This purple color indicates that there are still starches present which need to be converted to sugars, or more simply, that your mash is not yet finished.

45 minutes later another iodine starch test indicates that the color has changed and I am satisfied that my mash is finished.

Iodine after conversion.jpg

SAFETY NOTE: discard any wort you mix with iodine! And always clean the shotglass between uses.

Time for me to take a reading with my specific gravity hydrometer to determine where my mash has finished. I cooled the sample to 80F which means I must add .025 to my reading for temperature compensation:

Sg reading.jpg

That's 1.042 which compensates to 1.067, roughly 1.65 brix, 9.5% potential alcohol by volume. Not bad!

Next I transfer the wort to two sanitized 6.5 gallon carboys:

Rye in carboys.jpg

My 9 gallon mash will fit into two 5 gallon carboys, but I prefer to leave some headspace for foaming. I did 9 gallons because I have a gallon of feints saved for a total volume of 10 gallons.

Pitch yeast, put into a dark room and wait!