Stepped Infusion Mashing
- Copy of stepped infusion mashing e-mail article as promised.Simon,
Potatoes are harder than most people think and you need a bit of
experience to get them right. Books make it sound so easy because they tend
to simpIify the process and take for granted that you have a full
understanding and experience of all the steps involved quite often leaving
out some of the elementary steps. Most of us need to fully understand the
basics first before we really begin to learn. I have not tried potatoes yet
myself but know this from my reading, broad experiernce of other aspects,
and experience with other forms of starch.
What you will probably need to do is what is called a Stepped Infusion Mash.
This is where you start the saccharification process at a low temperature
and then move it up in steps, halting for a certain time period at each step
to give each enzyme time to break down as much as they can at each stage. If
you have made beer in the past using an all-grain mash you will understand
To get a feeling for it and to understand the process better try the
1) Cook your potatoes so they are still stiff - about 12- 15 minutes at
reasonable heat. Up to 20 minutes at low heat.
Note they should still be a bit undercooked, definitely not soft, mushy, or
2) Add coarsely milled barley (particles mostly about 1/16 to 3/32" in size.
Definitely not too fine.). Use malted Ale barley or standard malted barley
rather than Lager barley as it is definitely higher in enzymes and enzymatic
Note you need sprouted malted barley not spray-dried malt which is normally
on a maltodextrin base and has had most of the enzymes destroyed or
inactivated because of the excessive heat used in the drying process.
3) Cover with sufficient water and bring to 113 F (45 C). Hold 15 minutes
4) Bring up to 133 F (56 C). Hold 15 minutes etc.
5) Bring up to 149 F (65 C). Hold 15 minutes stirring constantly.
6) Bring up to 158 F (70 C). Hold 15 minutes stirring constantly.
All up this makes 60 minutes which should suffice for a small batch. Some
batches will take longer especially bigger batches. Most of the liquifaction
and saccharification occurs in steps 5 & 6 rather than 3 & 4. If you want to
alter this reduce 3 & 4 to 10 minutes and increase 5 & 6 to 20 minutes or
longer where required.
7) Once virtually all the starch is liquified and broken down to simple
sugars to halt the enzymatic process raise the temp to 176 F (80 C) (Mashing
Out) and then drop it back as quickly as possible to between 140 F (60 C)
and 122 F (50 C) so the sugars dont get scorched or burnt.
8) Cool down further to 75 F (24 C), establish an SG of 1060 (min) to 1080
(max = ideal) and begin fermentation.
If you muck around with the basic formula doing several batches, altering
the temperature and times a small amount each time you will quickly get a
feel for it and learn far more than you can learn initially out of books or
I can spell out for you.
I suggest you start with 3 or 4 kg of potatoes and 1/2 kg of barley each
time so you have plenty of enzymes together with a very large pot so it
dosnt boil over. Once you have got this basic process under control and
gained a bit of experience I can help you further with advice and help with
enzymes. Also once you have the experience and understand fully what you are
doing with the right selection of enzymes you can reduce this 4 to 5 steps
down to 2 or 3 steps and save a lot of energy and time producing virtually
the same result.
At first for the small amount produced it hardly seems worthwhile but you
will be amazed at how quickly you have control of the process with a bit of
experience. Learn this process properly now and it will save you a lot of
To help you further I have dug out and am sending you a simple sugar primer
I wrote a few months ago. Have a look on Tony Acklands excellent site.
There is probably more information there.