Partial Mash Starter

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Hi, I know this has been covered a number of times before and I have read the threads and am trying to pull them together. I thought it may be useful to gather all the details in the one spot that others may also be able to follow. I have numbered the steps that I think you could include in a partial mash.

I was hoping that others could comment on the temps, order of steps and volumes of water (eg how much per kg of grain). We can assume a full boil of the entire volume. I am looking at a basic process though I have broken it down to the individual steps (including some which you may normally assume).

I will be doing my first partial in 3-4 weeks, just need to get a few more bits of equipment. So far I have a
50l SS Pot (bit thin on the bottom but I have not scolded anything yet)
5l pot
small, medium and large esky

I am the process of building a immersion chiller and locating a large colander.
Perhaps people could add what they think are the minimum requirements for equipment.

After I do my partial i will collate the info into one posting.

1.Crack the grain bill
2.heat 1.35 L or water per kg of grain to strike temp70c
3.prepare mash tun eg esky (you can heat with some boiling water), pot (in oven or on stove)
4.Mix grain in tun with water to achieve a temp of 65-68c
5.instulate mash tun and mash for 60-90 min
6.heat 1.35L per Kg rest water to temp 70-80c (optional)
7.pour water onto mash and rest for 15 min. (optional)
8.heat 1.35L/ kg sparge water to temp 76-77c
9.strain entire grain bill with colander into pot.
10.pour wort back over grains (optional)
11.slowly sparge the grains with the sparge water into brew pot up brew pot to required volume
13.bring to boil
14.turn off flame add extract
15.bring to boil 60min
16.add hop additions
17.chill wort
18.strain into fermenter up fermenter if not doing a full volume boil

By the way I plan to do a Hefe Wiezen Dunkel as my first partial, but I will ask for recipes in another thread.
A couple of thoughts.

One of the most important items is a thermometer that is reasonably accurate. For all grain mashers a very accurate thermometer is needed, plus/minus half a degree. A partial mash is probably ok plus/minus 1-2 degrees.

Your expression of grain ratio should be water volume:1 kg grain. The half kilos can be a bit confusing, a partial mash of 1/2 a kilo grain is not going to be really meaningful, 2 kg is more suitable and that very first partial lays down good and bad habits of brewing. The ratio should be 2.5 to 1. There are very good reasons for varying this, but this is not in the realm of partial masher or new all grainer.

The ability to hit the correct strike temp for your expected mash temp is very important, most conversion happens in the first 20 minutes of mashing. Taking good notes of grain temp, grain volume, water volume, water temp and settle volume will make the next mash easier to predict. No-one expects a first mash to be perfect, and having cold and boiling (not simmering) water on hand is very important and easy to adjust the temperature. With these adjustments, the water:grain ratio will quickly blow out, this is also one reason to use the 2.5:1 rule.

The gear that people will use to partial mash will be wide and varied depending on what they buy, what they have on hand and what they can scrounge. Some people reading a thread love the format 1. add this, 2. heat this, 3. use this and get confused if too many options are offered. Others like to be more flexible in their approach.

Don't forget the basic cheesecloth for your colander. This can be pegged over a large saucepan for sparging through. A larger piece can be used in a spare fermenter, with some sort of stand off to stop it sitting on the bottom of the fermenter, it makes a cheap way of getting into partial mashing and even all grain. With a bit of insulation around the fermenter you have an instant mash and lauter tun.

How about in your final edition, you post all the links to other partial mashing information that you come across. These could be older threads from AHB as well as from other sites.

80 degrees is a bit too high to sparge with, stick to 70-75 degrees.

Don't forget, after adding the extract to stir thoroughly to dissolve it.

Have fun with your mashing.
Thanks for posting all this information. I am putting together all the info I can and am going to attempt my first partial when I feel confident enough to try.
Good luck with yours and thanks POL also for replying.
No problems oddball,

hope it will help a few people like ourselves trying to make the next step and having trouble wading through all the info.

Cheers POL

BTW the rest water at 70-80 if for an optional "mash out"

Is 'Hot side aeration' an issue here? with all the straining through colanders and splashing of hot wort etc.
Is this something that needs to be minimised?

Shed, the answer is democratic here. The answer is "Maybe???"

Highly debatable. I would do all i could do to minimse splashing though. ie running the wort down the side of the container etc.

I am of the view that if you can control a variable easily, the variable should be dealt with, HSA being something that can be easily dealt with


I agree Kungy,
I avoid aeration until the temp gets down to under about 26deg

What sort of 'off' taste do you get from aeration? Is that a 'grassy' taste?

I think like most things in terms of flavour and infections etc i find it hard to identify as i have no clear benchmark as none of my mates brew and i haven't entered any comps yet.

You mean HSA by aeration i assume. The overall consensus is it tastes like-

Oxidation is probably the most common problem with beer including commercial beers. If the wort is exposed to oxygen at temperatures above 80F, the beer will sooner or later develop wet cardboard or sherry-like flavors, depending on which compounds were oxidized. (


Cardboard, paper, wet paper, sherry-like, rotten fruit, garbage are all characteristics of oxidation, perceived both as an aroma and a flavor.

If you have grassy taste, suggests it is due to

Poor quality malt, poor storage of malt, cracking grains well in advance of brewing

And from other guys on this forum, dry hopping can sometimes cause this.

The second website is the best site i have found concerning off flavours. It is the only site that has a good section on nutty aromas, which i had a big problem on my first AG. Rather than a APA it was a peanut ale

I wouldn't worry about HSA in part mash brews--they all get drunk way b4 and staling happens

Jovial Monk
Yeah not worried about HSA in a partial. really just after comments on the process here, good or bad. Of course I welcome comments about any parts of the process that may contribute to an off flavour, though only if it is a glaring issue.
Updated notes on how to do a partial mash. Please remember these are purely some instruction for a relative beginner. Thanks to those who contributed both at Aussiehomebrewer and Grumpy's. If anyone spots so errors or would like to add more, go ahead and I will update as required.

Partial Mash Process:

1. Crack the grain bill

2. Heat 2.5L or water per 1 kg of grain to strike temp70c

3. Prepare mash tun eg esky (you can heat with some boiling water), pot (in oven or on stove)

4. Mix grain in tun with water to achieve a temp of 65-68c

Note: Have some cold and boiling ready to adjust mash temp

5. Insulate mash tun and mash for 60-90 min

Note: If using a pot you can place it in an oven set at mash temp or slightly below.

6. Optional Step - Heat 2.5 L per 1 kg rest water to temp 70-75c

Note: This will be the water for a Mash out

7. Optional Step - Pour water onto mash and rest for 15 min.

Note: Most often called a mash out

8. Heat 2.5L/per 1 kg of sparge water to temp 70 - 75c

9. Strain entire grain bill with colander into pot.

Note: Could peg a cheese cloth over the pot as an alternative

10. Optional Step - Pour wort back over grains

Note: This is to filter the wort

11. Slowly sparge the grains with the sparge water into brew pot

Note: If you brew pot is large enough you could sparge your total volume of water required for the brew.

12. Top up brew pot to required volume

13. Bring to boil

14. Turn off flame add dry or liquid malt extract

Note: If you are adding hopped extract a boil will destroy the hop flavours and aromas. Some people recommend to add extract (LME and DME) after the boil has finished or in the last ten minutes. You will have to account for this in your hop calculations.

15. Bring to boil 60min

16. Add hop additions

17. Chill wort

18. Strain into fermenter

19. Top up fermenter if not doing a full volume boil

Equipment list.

Accurate thermometer (for Partial Mash an accuracy of 1-2 degree is required, for All Grain .5 degree)

Small esky, 20l pot or bucket for mash tun

Something to strain your grain eg colander, cheese cloth

Just to confuse you, another link:

I agree with pretty much all your steps, but recommend you don't recirculate the wort and sparge fast not slow, all to stop the wort and grains cooling off too much

Jovial Monk
NB both the manual and website as a whole not yet complete but getting there

Yep I had a look at your link and it most definately deserves to be included. Noticed your temps are a little higher than mine, in fact my original temps were closer. Not to worry they are close enough.

For another partial mash method,m that's probably easier and quicker than most:

Partial Mash

Blue Mtns Brewing Supplies
I can vouch for Pat's quick partial mash method, I have made 3 of these now, the are dead easy and the results are great.
I tried a no sparge partial after following a link from Pats message last week about his demo.

I did a partial mash stout a month or two back (my first partial and first stout) and wasn't too impressed by the results.

I thought this looked pretty idiot proof, only one lot of water to prepare etc etc and I was pretty much right.

I buggered about getting the mash temperature right and ended up adding about 17 litres instead of 14 and I got 15 litres to boil

Also forgot the part where it says drain the wort slowly, reckon it must have run through in 2-3 minutes using a bucket in bucket tun.

What rate should I run it off at - is slower better - a litre a minute ?

The result after the boil and adding 1.5kg extract was 1.042 in 22 litres in the fermenter which I was pleasantly suprised by, I'd expected a lower extract rate.

But, it's in the barrel bubbling away happily now though and the second attempt this week should be a lot smoother and closer to what was intended !
jaytee said:
What rate should I run it off at - is slower better - a litre a minute ?

How to Brew by John Palmer recommends a run-off rate of just under 0.95litres\minute. That's the way I go for my partials as it's good practise for AG. :D
Yesterday I did my first partial following the instructions I put together in this thread. The instructions were great to follow and I was not caught out at any stage. (wether or not they are good instructions is another story)

This was my recipe.

I was after a Hefe Dunkel or similar.

3kg Cooper LME
500g Vienna Malt
500g Wheat Malt
250g Hoepfner Wheat
250g Thomas Fawcett Crystal wheat
150g Melanoidin
100g Carafa Special 2

45g Tettnanger 3.9% 60min Boil

Wyeast 3942 (not perfect but all I had)

Half a tab of Whirlfloc

I used 5L for my Mash and managed to hold a temp of about 66 degree for 75min. I then added about 3L water at 70 degree for a 15min rest.

It all seemed like a fair amount of water to me.

Had a little trouble lautering because my colander and second pot was a little small (need to sort something out there - bucket in bucket perhaps) and I was also heating my sparge water in my kettle. Anyway I had to transfer my wort around a bit and after transferring my sparge water around a bit I dropped it's temp from 75 down to about 65 by the end.

Not sure what my total volume was but I topped the kettle to 27L and started the boil. Took an absolute eternity to get to the boil and then only maintained a good boil with the lid on ( need a stronger burner). Hence little liquid lost in the boil and my final volume of wort was a bit much aiming for 23L and had about 26L.

The immersion chiller I had made the day before worked a treat. Chilled the wort to about 24 in just over 20min.

My SG was 1.046 at 24 degree.

My yeast starter was very good and I had some action in the fermentor only a few hours later. This morning it was going strong.

Well that was how it went. Any comments on the process or recipe, would be greatly appreciated.
Well done Cubbie, not long now and you will be enjoying your brew.

If you make a bucket in bucket, you can up the mini mash grain quantities.

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