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Partial Mash Question


ChristinaS1

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Hi all,

 

I am still a partial mash beginner. I have only done a few very small ones, mashing a bit of Aromatic, with limited success; I may have been doing them wrong. At the end of the mash I have just been heating the wort to stop the enzymes, then adding it to my Coopers kit. Occasionally I have used the partial mash wort to boil my flavour and/or aroma hop additions, but I have not been paying attention to whether or not hot break has occurred.

 

Before going any further down the partial mash road (I am thinking about increasing the size of my partial mashes to 2kg - mostly base malts) I want to make sure I am doing them right. Do I indeed have to boil the partial mash if I add it to a pre-hopped kit? If so, for how long? I suppose it is necessary to boil it at least until hot break occurs? Do I have to boil it any longer than that? Thanks in advance for your help everyone. Looking forward to your answers. happy

 

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Do I have to boil it any longer than that? Thanks in advance for your help everyone. Looking forward to your answers. happy

 

Yes, you need to boil off DMS precursors. I would go a minimum of 30 minutes.

This has some good information ... http://beersmith.com/blog/2012/04/10/dimethyl-sulfides-dms-in-home-brewed-beer/ no need to boil for 90 minutes however.

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Do I have to boil it any longer than that? Thanks in advance for your help everyone. Looking forward to your answers. happy

 

Yes' date=' you need to boil off DMS precursors. I would go a minimum of 30 minutes.

This has some good information ... http://beersmith.com/blog/2012/04/10/dimethyl-sulfides-dms-in-home-brewed-beer/ no need to boil for 90 minutes however.[/quote']

 

Wow, something else to worry about. w00t I had no idea.

 

Thanks for the link Ben. smile It was very informative.

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Hi Christina.

 

+1 to what Ben said.

 

Once moving over to partial mashing, using the KISS principle, you'll just need to make sure you do one thing. Add a percentage of base malt as part of constructing the grist for your mashes.

 

Base malts such as Pale ale malt, Pilsner malt, Maris Otter, 2-row pale malt, 6-row pale malt have high diastatic power that enables them to not only self convert the starches their own weight produces in the mash, but they also have the ability to convert the starches produced by other grains in the mash that have low to no diastatic power.

 

In the case with your Aromatic malt mash, this particular grain has low diastatic power & I'm led to believe lacks enough enzyme activity to completely self convert if mashed without the accompaniment of some portion of base malt. Thus your mash here would probably have left an amount of unconverted starch in solution, that has then been mixed in with your extract based ingredients. Because part, or all of the Aromatic malt has not been converted to a fermentable sugar through the mash, the yeast once pitched cannot consume it & convert it to alcohol etc. Thus the starch becomes an unfermentable ingredient & can contribute to haze, trub levels etc.

 

All I do is make sure I have at least 1/3 - 1/2 of my mash based malt grist comprising of high diastatic base malt(s). Simple.

 

If you feel like a bit more info & a free headache, there is a formula for estimating the diastatic power of your all grain mash grist. That can be found HERE.

 

Being able to add a component of grain derived wort into your extract base mix will improve the quality of your beer & give it a noticeable freshness approaching what the all grain guys enjoy. cool

 

Good luck with it moving forward,

 

Lusty.

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Hi Christina.

 

+1 to what Ben said.

 

Once moving over to partial mashing' date=' using the KISS principle, you'll just need to make sure you do one thing. Add a percentage of base malt as part of constructing the grist for your mashes.

 

Base malts such as Pale ale malt, Pilsner malt, Maris Otter, 2-row pale malt, 6-row pale malt have high diastatic power that enables them to not only self convert the starches their own weight produces in the mash, but they also have the ability to convert the starches produced by other grains in the mash that have low to no diastatic power.

 

In the case with your Aromatic malt mash, this particular grain has low diastatic power & I'm led to believe lacks enough enzyme activity to completely self convert if mashed without the accompaniment of some portion of base malt. Thus your mash here would probably have left an amount of unconverted starch in solution, that has then been mixed in with your extract based ingredients. Because part, or all of the Aromatic malt has not been converted to a fermentable sugar through the mash, the yeast once pitched cannot consume it & convert it to alcohol etc. Thus the starch becomes an unfermentable ingredient & can contribute to haze, trub levels etc.

 

All I do is make sure I have at least 1/3 - 1/2 of my mash based malt grist comprising of high diastatic base malt(s). Simple.

 

If you feel like a bit more info & a free headache, there is a formula for estimating the diastatic power of your all grain mash grist. That can be found HERE.

 

Being able to add a component of grain derived wort into your extract base mix will improve the quality of your beer & give it a noticeable freshness approaching what the all grain guys enjoy. cool

 

Good luck with it moving forward,

 

Lusty.

 

Thanks Lusty. smile

 

Do you partial mash often? With the larger mashes I have planned, I am switching to using a 8.5L beverage cooler. What size cooler do you use? I am guessing/hoping I will be able to get 2kg of grain in there, to avoid having to use DME and LME. I am pretty sure that 2kg of grain will not take up 2L of space. How much water do you think I will be able to fit in? Is it true that you don't have to worry about mash pH with the amounts used in partial mashes? I may steep any specialty grains in the recipe separately, in order to maximize the amount of base malt I can fit into the cooler. Is that a bad idea or a good idea, in terms of mash pH? I have a well; the pH is about 7.2 (Edit: it is ph 7.9). I also buy RO water to dilute my extract with. Which of the two types of water would you advice I use if I only mash base malts and no specialty grains?

 

Sorry for all the questions. rolleyes

 

Thanks in advance for your answers.

 

Maris Otter, here I come! lol

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I may steep any specialty grains in the recipe separately' date=' in order to maximize the amount of base malt I can fit into the cooler.[/quote']

 

Crystal type grains can benefit from the enzymes in the base malt too.

And on mash pH - are you sure it is 7.2 or is that the initial water pH? The mashing of the grain alters the pH of the fluid mass itself.

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I may steep any specialty grains in the recipe separately' date=' in order to maximize the amount of base malt I can fit into the cooler.[/quote']

 

Crystal type grains can benefit from the enzymes in the base malt too.

And on mash pH - are you sure it is 7.2 or is that the initial water pH? The mashing of the grain alters the pH of the fluid mass itself.

 

Sorry for being unclear: I did mean that the pH of my well water, as it comes out of the tap, is 7.2, but I mis-remembered, it is actually 7.9....I only just bought some "Precision" pH strips to start testing the mash. I have not yet attempted a 2kg partial mash.

 

I just checked the pH of my RO water and, if the strips are to be believed, it is about 5. Does that make sense? The RO has a different source (city water supply).

 

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Do you partial mash often? With the larger mashes I have planned' date=' I am switching to using a 8.5L beverage cooler. What size cooler do you use? I am guessing/hoping I will be able to get 2kg of grain in there, to avoid having to use DME and LME. I am pretty sure that 2kg of grain will not take up 2L of space. How much water do you think I will be able to fit in?[/quote']

Hi Christina,

 

With my little 10 litre and now 15 litre cooler mash tuns I found the these calculators helpful. You may be particularly interested in the 'Can I Mash It?' one. I found it fairly accurate.

 

2kg of grain mashed in 6 litres of water (at a 3:1) liquid to grist ratio will take up 7.34 litres of space so you will be fine.

 

Cheers,

 

John

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Do you partial mash often? With the larger mashes I have planned' date=' I am switching to using a 8.5L beverage cooler. What size cooler do you use? I am guessing/hoping I will be able to get 2kg of grain in there, to avoid having to use DME and LME. I am pretty sure that 2kg of grain will not take up 2L of space. How much water do you think I will be able to fit in?[/quote']

Hi Christina,

 

With my little 10 litre and now 15 litre cooler mash tuns I found the these calculators helpful. You may be particularly interested in the 'Can I Mash It?' one. I found it fairly accurate.

 

2kg of grain mashed in 6 litres of water (at a 3:1) liquid to grist ratio will take up 7.34 litres of space so you will be fine.

 

Cheers,

 

John

 

Thanks for the info John. That is a great link! biggrin

 

Now I just need to figure out my water/mash pH. wink

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Do you partial mash often? With the larger mashes I have planned' date=' I am switching to using a 8.5L beverage cooler. What size cooler do you use? I am guessing/hoping I will be able to get 2kg of grain in there, to avoid having to use DME and LME. I am pretty sure that 2kg of grain will not take up 2L of space. How much water do you think I will be able to fit in? Is it true that you don't have to worry about mash pH with the amounts used in partial mashes? I may steep any specialty grains in the recipe separately, in order to maximize the amount of base malt I can fit into the cooler. Is that a bad idea or a good idea, in terms of mash pH? I have a well; the pH is about 7.2. I also buy RO water to dilute my extract with. Which of the two types of water would you advice I use if I only mash base malts and no specialty grains?[/quote']

+1 to everything Ben & John said.

 

The bulk of my brews over the last few years have been partial mash beers. I'm still a kitchen brewer & don't use a traditional mash tun or cooler setup. I actually use an 8 litre pot & my oven for my mini-mashes. If you're interested, a couple of years ago I posted a pictorial walk-through of how I do this.

 

A Beerlust Brewday.

 

I can get away with mashing & sparging up to about 2kgs of grain, but find approx. 1.5kgs a comfortable level for my setup. You can certainly mash base malt separately to a grain steep, but as Ben said, you will benefit from including the specialty grains in with your base malt grains in the mash, & this is what I do.

 

Some of the more technical aspects, I'll leave for the more experienced AG brewers to discuss with you, as I have deliberately maintained a very simple approach to this area of my brewing, & tried not to over complicate things. wink

 

One thing I can promise you, is you'll love the results a good whack of fresh grain can add to the flavour(s) of your beer. Being able to partial mash opens the door to the complete range of grains you can now experiment with. cool

 

Cheers,

 

Lusty.

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Whilst I appreciate what several of my brethren have said, I just like being a contrarian. rightful

 

You can get away with quite a bit in a partial mash (but that's what is really happening here -- yoiu are only getting away with it). That's because, depending the size of the partial mash, the proportion of the all-grain mash is only 10 or 20 or 30 or 40 percent of the volume, and you are diluting the unwanted molecules considerably with extract that been made properly, and water.

 

In the vast majority of instances in a partial, that dilution will cover up the problems, but with some it may not. And if you go the next step where the grain mash is nearly 100%, you usually won't be able to hide the errors.

 

Christina, here's a short 3 page, factual excerpt that should be a must read called The Function of Boiling Wort. I'm sure it will give you a lot of insight into this thorny topic.

 

Cheers

Phil

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Okay everyone, messages received:

 

1.) mash specialty grains together with base malt.

2.) don't try to cut corners in the mashing process.

3.) boil the partial mash wort for about 40 minutes, or longer.

 

I guess part of #2 is trying to control pH of the mash? The first couple of partials with my new set up will provide me with a better idea of what kind of pH I will get with my water and I can experiment.

 

To recap: the RO water is pH 5, my well water has pH 7.9. For starters I am guessing:

 

- all base malt - use 100% RO

- combo of base malt and crystal, +/- roasted grain - 50:50 split RO to well water

- combo of base malt and roasted grains (stout, porter) - use 100% well water

 

Does that sound reasonable? After the grains have mixed I can test and adjust the pH up or down as needed.

 

Is there anything else I need to do?

 

Thanks for your help, one and all! Much appreciated.

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Hi to the Big C

 

I'm not saying it's wrong, but I am surprised RO water is coming out at around a pH of 5; I would have expected that with the RO process removing almost all salts and TDSs that it should have been within a point of pH 7 (irrespective of the pH of the original well water).

 

Having said that, you can make some generalisations without resorting to adding salts and things (which is really just the icing on the cake and the last thing I'd bother looking at). For light coloured beers (pale ales, APAs, lagers etc) ideally a pH in the mash of 5.1 to 5.4 is good. You will get an acidifying effect from the grains, but often not quite enough to get the mash in that range.

 

For darker beers often the ideal target is somewhere between 5.3 and 5.6. The darker colour is often (or usually) derived from darker specialty grains which have a larger acid effect on the mash water than lighter or less roasted/kilned malts. So in some cases, there is much less, if any, further lowering (or more acidifying) of the mash water needed to get it exactly where you'd like it to be.

 

Noting that my treated town water has a pH of 8.2 to 8.3, I've found a tiny addition of Acidulated Malt (from Weyermann) goes a long way to getting the pH in the perfect range. So while for me about 2% of the mashed grain for light coloured beers and maybe 1.5% for dark beers is perfect, if you went that path I'd suggest 1.5% and 1% respectively. So 1 kg Acidulated Malt would last you a long long long time in partials. (NB: A because it has a really good buffering effect over quite a range, if you put in 3 or 4 times too much accidentally it wouldn't be catastrophic).

 

Of course, none of this addresses residual alkalinity which is an entirely different topic for another day, but it also is the last thing you should bother looking at.

 

All the best and be good(ish)

Philster

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I'm not saying it's wrong' date=' but I am surprised RO water is coming out at around a pH of 5; I would have expected that with the RO process removing almost all salts and TDSs that it should have been within a point of pH 7 (irrespective of the pH of the original well water).[/quote']

 

Hi Phil. You may be quite right about that. My strips only measure 4.8-6.2. The pH of the RO may have been out of range of the strips. I really had to squint to see any colour change at all, and when they are dry they look like pH 4.8.

 

The rest of the information you provided was also very helpful. The voice of experience! I will get some Acidulated Malt at my LHBS.

 

Have a good day Mr. Phil. kissing

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The bulk of my brews over the last few years have been partial mash beers. I'm still a kitchen brewer & don't use a traditional mash tun or cooler setup. I actually use an 8 litre pot & my oven for my mini-mashes. If you're interested' date=' a couple of years ago I posted a pictorial walk-through of how I do this.

 

A Beerlust Brewday.

 

 

Cheers,

 

Lusty.[/size]

 

Hi Lusty, thanks for your response. I looked at your Brewday pictures, neat. The very first time I did a partial I did it in the oven but it totally did not maintain mash temperature. Mostly that is because my oven is not very accurate (it is about 50F cooler than the dial). crying For subsequent mashes I switched to a 1.5L insulated mug (which allowed me to mash up to 400gm), and now I am switching to a 8.6L cooler, for 2kg partials. Coolers work better for me.

 

BTW, did you ever resolve the astringency issues you mentioned last winter? If so, what was the cause?

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BTW' date=' did you ever resolve the astringency issues you mentioned last winter? If so, what was the cause?[/quote']

I'm still in the early stages of testing a couple of areas to try & find the source. I spoke with my LHBS owner recently about it, & she suggested it can sometimes occur from over-sparging. I was a little surprised by that, given I feel I predominantly under-sparge in most cases.

 

On some advice from Hairy, I purchased some campden tablets a little while back, & have used them on a large percentage of my top up water on a couple of brews believing the astringency might be chlorine/chloramine water based. Both brews turned out well but neither had large grain inclusions, so I admit I can't be sure of anything on that front yet either.

 

The astringency isn't to a level where I say, "@#$% I need to stop brewing & sort this out!". It's just a slight & noticeable undertone in the beer I want rid of.

 

I'll sort it out eventually, but for now it's very much still a work in progress.

 

Cheers & good brewing,

 

Lusty.

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BTW' date=' did you ever resolve the astringency issues you mentioned last winter? If so, what was the cause?[/quote']

I'm still in the early stages of testing a couple of areas to try & find the source. I spoke with my LHBS owner recently about it, & she suggested it can sometimes occur from over-sparging. I was a little surprised by that, given I feel I predominantly under-sparge in most cases.

 

On some advice from Hairy, I purchased some campden tablets a little while back, & have used them on a large percentage of my top up water on a couple of brews believing the astringency might be chlorine/chloramine water based. Both brews turned out well but neither had large grain inclusions, so I admit I can't be sure of anything on that front yet either.

 

The astringency isn't to a level where I say, "@#$% I need to stop brewing & sort this out!". It's just a slight & noticeable undertone in the beer I want rid of.

 

I'll sort it out eventually, but for now it's very much still a work in progress.

 

Cheers & good brewing,

 

Lusty.

 

Hi Lusty. Yes, sparging, I too have read that over-sparging can be a cause, but if you aren't over-sparging, then it must be something else; since it was less noticeable in your brews with smaller grain inclusions, maybe it has something to do with your partial process?

 

I just realized that with my very tiny mini-mashes (<200gm) I was not sparging properly. I was just rinsing, same as when I was steeping specialty grains. Anyway, I have been reading to use the same amount as your strike water, although 4L/kg is also mentioned often, and some say as high as 6L/kg, so I am a bit confused. What do you use? Some people do two soaks and some one. Since I use a grain bag, I think I will start with 4L/kg and do one soak starting at 77C for 10-15 minutes, which sounds nice and simple.

 

But to get back to your astringency issues it occurred to me, when you said you try not to complicate your brew day with water chemistry, that perhaps that is where the issue might lie? I am a complete N00B at this, but it might be something to consider? Some things I have seen mentioned as possible sources of tannins are mash ph >5.5, sparge water pH >6, sparge water temp >77C. You have probably read this link before, but I will put it in for the benefit of others:

 

http://beersmith.com/blog/2012/06/19/phenolics-and-tannins-in-home-brewed-beer/

 

Anyway Lusty, it is time for me to go to bed. Take care, and nice talking to you. -Christina.

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I can get away with mashing & sparging up to about 2kgs of grain' date=' but find approx. 1.5kgs a comfortable level for my setup.[/quote']

 

I just did the math and, based on the size of my kettle, I may be wise to follow your example and reduce the size of my partials to 1.5kg. I don't want boil-overs.

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But to get back to your astringency issues it occurred to me' date=' when you said you try not to complicate your brew day with water chemistry, that perhaps that is where the issue might lie? I am a complete N00B at this, but it might be something to consider? Some things I have seen mentioned as possible sources of tannins are mash ph >5.5, sparge water pH >6, sparge water temp >77C. You have probably read this link before, but I will put it in for the benefit of others:

 

http://beersmith.com/blog/2012/06/19/phenolics-and-tannins-in-home-brewed-beer/[/quote']

I reckon you might be onto something here. It's not something that a few of the other boys on the forum haven't already touched on, but from memory astringency wasn't mentioned among the discussions I've read.

 

I hadn't read the article in the link you posted, & still haven't as it just loads a blank page for me. tongue

I did however have a look around the Beersmith Blog page while I was there, and as luck would have it, a short & concise article on this very subject of astringency was posted just 3 weeks ago! happy

 

A perfect article that explained how the astringency can present from grain if you don't adhere to a few guidelines. A good read for those interested.

 

BeerSmith Blog: Astringency from Grains - Oversparging and Hot Sparging Your Beer

 

If I want to get on top of this astringency issue, I may have to concede I'll need to start measuring wort pH levels. pinched

 

Cheers,

 

Lusty.

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  • 3 months later...

Rather than start a new thread, I'll plonk this information on ph levels in water here.

 

Having started partial mash and looking ahead to BIAB, I've been looking through ph levels in water in attempt to better understand the profile measurements in online calculators. Instead of going out and immediately buying measuring implements, I did a search on line on water quality here in WA. The Water Corporation puts out an annual report each year which includes details on ph levels for each locality as well as a detailed breakdown of chemical composition. Not sure if other water authorities in each state do the same thing?

 

The link to this report is below, and the Perth Metro measurements are in Table 4 on Page 42 if anyone needs them. It seems they do a number of measurements each year which provides a min, max and mean. Its a starting point if nothing else.

 

http://www.watercorporation.com.au/-/media/files/about-us/our-performance/drinking-water-quality/annual-report-2015.pdf

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Hi Chalswi. Good info for partial mashers who live in Perth.

 

Just thought I would give an update on my own experience with measuring pH. As I mentioned earlier, I started out with pH strips, which have their limitations that I became frustrated with. Eventually I bought a pocket pH meter which came with a bit of pH 4 and pH 7 for calibration. Ideally you ought to calibrate at the start of every brew day. In addition you need to keep the probe wet at all times, for which I used the pH 4 solution. Needless to say I quickly ran out of pH4. My LHBS only sells tiny envelops for a steep price, and unsustainable price. I am probably going to have to order some online, which isn't cheap either, and has shipping costs on top, or give up and go back to strips.

 

So yeah, if you are thinking about getting a pH meter, first look into the cost and availability of calibration solutions in your area. If your application is not mission critical, and your use is occasional, you may be better off with the strips.

 

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  • 3 years later...

I'm thinking of starting to do some partials in order to get some oatmeal in some winter brews. Do people find it simpler and easier doing it with grain in a bag, or just letting it go commando in a large pot?

Also want to use some biscuit malt for a few brews, can that be cold steeped, or does it need to be mashed?

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It depends on what you have. I have done it with a grain bag and without, I found it easier to just lift the grain bag out and let drip but you might like straining them out. With bigger malt bills, in the partial mash, it makes it tougher to strain them with a strainer.

Biscuit malt can be cold steeped.

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17 hours ago, alilley said:

I'm thinking of starting to do some partials in order to get some oatmeal in some winter brews. Do people find it simpler and easier doing it with grain in a bag, or just letting it go commando in a large pot?

Also want to use some biscuit malt for a few brews, can that be cold steeped, or does it need to be mashed?

I do it both ways but do find using a bag generally more convenient - particularly for larger grain weights.  Biscuit malt should be mashed IMO.  I can tell you from experience that if you just steep it you will end up with a very starch-hazed beer!   

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