Mash out

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
The first runnings with boiling water come out under 78*c. Its not the third running that the temp hits the 80* mark

You will be surprised that boiling water does not raise the temp as much as you think.

When I first told brewers I used boiling water most of them them stood back and went WTF. your crazy... :)


I know exactly how much it goes up because I've done it, multiple times.

You're right - if going from sacch to sparge, it won't go near 80.
 
When I was brewing by infusion mash out temp all 10 litres was 97c to 98c
Depended on sach rest time of the year

I found stiring the best as I underlet measuring as it went in because I was paranoid about it going over 78c
same with my sparge which was 20 L at 85c to 86c to get 76c to 77c
 
Critical in the commercial sense, not so much in a home sense

Stopping enzyme activity and making a better flowing wort stream matters in the big houses with large charges of malt. Even at the 20hl range I did it to help with pass thru our mash filter.

But at a 5kg, not 500kg, malt charge with a highly variable temperature across the mash, yeah I’d worry more about some water chemistry, yeast health and beer clarification.

Scotty

Enjoy your post mate helping the small guys out
Water chemistry, yeast health and beer clarification.are a good call
Clarification is more or less by water chem & time or are you talking filtering or adding biofine for clarity
Rude
 
Na bugga that mate, I'm a homebrewer and I don't take myself to seriously I'm not a commercial brewery I don't need to be producing the exact same product every time, iv done mash outs in the past and brewed the same beer without the mash out step and can't really notice the difference, brewing is my hobby not my job so i prefer a nice cruisey brew day which means the less piss farting about the better and my beer turns out well and truly drinkable.
 
Na bugga that mate, I'm a homebrewer and I don't take myself to seriously I'm not a commercial brewery I don't need to be producing the exact same product every time, iv done mash outs in the past and brewed the same beer without the mash out step and can't really notice the difference, brewing is my hobby not my job so i prefer a nice cruisey brew day which means the less piss farting about the better and my beer turns out well and truly drinkable.
I agree with the first part of that and the cruisy brew day part, but some of us do like to learn about the science of brewing as well, and why we do what we do. I also consider brewing a hobby, but that side of it is just part of the hobby for me and I find it really interesting. A mash out only adds about 20 minutes to my brew days, and helps drain the bag easier which makes my brew day easier. I'm not trying to produce the exact same product every time either, but I am trying to brew the best beer I can every time.
 
I agree with the first part of that and the cruisy brew day part, but some of us do like to learn about the science of brewing as well, and why we do what we do. I also consider brewing a hobby, but that side of it is just part of the hobby for me and I find it really interesting. A mash out only adds about 20 minutes to my brew days, and helps drain the bag easier which makes my brew day easier. I'm not trying to produce the exact same product every time either, but I am trying to brew the best beer I can every time.
Yea that's a good point too rocker mate, iv just found in the past that the mash out doesn't seem to affect the outcome of the finished beer to the point of it being noticeable but that could be me doing it wrong I'm not sure. Iv found that focusing more on the fermentation and yeast selection side of things is where the final beer quality is really noticeable as the boil is pretty straight forward just make sure it's a nice soild boil and everything is A OK. iv found ferment temp and good yeast to be the key plus obviously good sanitation, I know it's not my post but any tips when it comes to mash out would be awesome and I'd be greatful for all and any info.
 
The yeast and fermentation are probably the most important part of brewing, but they come after the wort has been brewed. Even good yeast and ferment temp won't save a badly brewed wort. I'm not suggesting not doing a mash out is bad brewing, but my experience has been that when I've forgotten to do it I end up falling short of my target pre-boil and post boil SG readings. This could throw the balance of the beer out if it falls short by too much, causing the beer to end up more bitter than expected.

I just brew BIAB and use a false bottom, my mash out method is basically to just heat the grains and wort up to about 78-80C and let it sit there for 10 minutes before hoisting the bag and draining it. Seems to work well enough.
 
Personally I think getting good temperature control of your ferment is more important than going all grain.

Getting back to Mash Out, I think its more useful to think of it as a mash process step, like a protein rest, scarification rest... Just the end event of a potentially useful range of temperature steps ye use to make the beer we want.

I rarely do glucan protein or rests (unless there is lots of adjunct) with modern malt, certainly couldn't be arsed doing a phytic acid rest (takes a couple of hours to be useful) but always mash out. It fixes the beers fermentable/dextrin ratio, makes lautering faster and improves the yield.

Mashing out can be as simple as running off the first wort and then starting the sparge with water (treated) that is hot enough to raise the bed temperature to around 80oC, By ramping up to around 80oC in a recirculating system or by making and addition of boiling (or just very hot) water.
The last is easy and just requires the same calculation as that used for any other step mash achieved by hot water infusion. The calculation is just a rearrangement of the standard mixing equation (Aa+Bb=Cc), with the added complexity of the total mass you are trying to raise the temperature of being a mixture water and malt with a relative thermal capacity of 0.4 that of water. We call the combined Malt and Water thermal capacity the Mash Heat Capacity (MHC) simply put it is {(0.4*Grain Mass)+(Water Mass)}/Total Mass
So for 5kg of malt that was mashed in at 3.5:1 {(0.4*5)+(3.5*5)}/(5+17.5)=0.8666666.

From there its easy enough to calculate exactly how many L (well kg actually) of hot/boiling water you need to add to raise the temperature of the grain bed to your target temperature (~80oC).
Mark

Edit
Sorry something came up and I had to cut short
Using the standard mixing equation and the information above the calculation is very easy
(MHC*mass*t)+(Mass hot water*t)=Total mass *target temperature
Rearranged to solve for mass of boiling water gives us
Mass Boiling Water = {(MHC*Mash Mass)*(Target Temp-Current Temp)} / (Boiling Water Temp-Current Temp)
Plugging in what we have
MHC - 0.8666666
Mash Mass - 17.5 (grain + mash water)
Target Temp - 80oC
Current Temp - 67oC (measure it)
Boiling Water Temp - 98oC (it wont stay at 100oC for long, better to allow a bit of loss)

Mass Boiling Water = (0.8666*17.5)*(80-67) / 98-80
= (15.16*13)/18
= 10.95
Call it 11L, better to have a bit in reserve.
 
Last edited:
Which pretty much proves my point that sparging with ( near as ) boiling water does not increase temp as much as people think, and does not bring tannins out

No it doesn't.
Using neat boiling water to raise the whole mash to close to 80oC (with lots of stirring) isn't the same as sparging with 100oC water.
The way a sparge works the top of the bed will get a lot hotter than 80oC as the boiling water works its way down, this will extract tannins.

As an aside modifying other peoples post for your own purposes is pretty rank, reply to what someone says, fine, but you have no right to modify someone else's work.
Mark

admin note: Meatball's modified quoted post hidden.
 
Last edited by a moderator:
what the frig? anyway. ill try and sparge witj hotter water
 

Latest posts

Back
Top