MASHING
Just Give it a Go !!
Let's face it, if there's one thing that puts people off getting into fully mashed beers, its the complexity of conducting yourself a mash ! Well, that and the time it can take. However, with time, this becomes less of a problem because your beer is so fabulous you'll wonder why you never started mashing before . . . biased I know . . . Just Give it a Go !!
Now, not wanting to overly complicate things but . . . mind if I use a diagram to explain a few things about why we're mashing in the first place ?! You see, a lot of people start out with kits because they're simpler (I did !) but you can definitely create a better beer if you have a better understanding of the process and hence the reasons for mashing in the first place. I put the following diagram together to confuse our brewing club members . . .
What it shows are four possible routes to achieving a hopped wort :-
- Both routes 'A' and 'B' take you first to an unhopped wort.
- Route 'A' shows how you mash malted barley, rinse (sparge) it and hence get an unhopped wort.
- Route 'B' show show someone else has already done the mash for you and concentrated the wort into a small volume. The result is a thick syrup called malt extract. Your job is then to simply add it to boiling water to reconstitute the syrup.
- Both routes 'A' and 'B' then require you to boil this (unhopped) wort and to add hops in order to get the bitterness, flavour and aroma components you desire.
- Routes 'C' and 'D' assume that you have bought a kit and added boiling water to reconstitute it. A kit is really nothing more than hopped wort that has been concentrated.
- Route 'C' assumes that you can spare some time and have decided to boil this wort for 15 minutes or so. You should really add your own flavour / aroma hops when you do this as the manufacturer's hops (if they're there . . .) will disappear into the ether as you boil.
- Route 'D' says that you have followed the instructions on the kit and simply added boiling water to reconstitute things.
Now, if you've read my 'brewing philosophy' page elsewhere on this site you will know that I consider process as paramount and I make much of "your degree of compromise". Going from route 'A' to route 'D' sees you compromising more and more and . . . you get the message right ?! Hence my (not so) cryptic message in the lower right hand corner of the above diagram.
So, you now know that mashing is just the higher life form of a kit and that all brewing gods used to do this before man discovered the true art of compromise !
But I digress . . . now back to some info on how to conduct a single temperature infusion mash . . .
So, you've read the preamble in the "Pre-Mash" section and you've just digested an odd looking diagram up yonder and you're now ready to dive into mashing . . . . here's how I approach the process for a single temperature infusion mash :-
- Add the mash liquor to the mash tun and stir to get a uniform temperature. Measure it with a thermometer too ! Record keeping is VERY important.
- At this stage I choose to add any minerals that I need. Adding minerals, as discussed in the pre-mash section, is a lot about achieving mash pH and a lot about achieving the right flavour balances in the final beer. The way I see it, if you take water from a famous brewing city, all of the liquor you use has the same mineral content. To replicate this in your homebrewing you could add the minerals one time to the hot liquor tank and as long as you don't dilute part way through the day in order to reheat, you will be fine.
- However, I find in my brew house that adding minerals to the hot liqour tank (I have an electrical heater) sees the element scale up. This causes much consternation on brew day (read "potential for rude language !"). Hence I don't add them to the hot liquor tank but choose instead to add them directly to the mash tun. So, the trick is to remember to calculate your minerals based on the volume of water you treat. So if you choose to add your minerals to the mash tun calculate based upon that volume. If you choose to treat your entire hot liquor tank then calculate based on that volume. (To get a leg up on the calculations for mineral treatment go check out the spreadsheet file.)
- Of course, the downside here is that the sparge liquor is then not treated with minerals either and so you end up with wort in the boiler, later on, with a diluted mineral profile. My answer, discussed under the boil section, is to "top up" the mineral profile in the boiler, for some reason I see very little scaling there . . . something to do with the chemistry of the wort versus the chemistry of water ?! Something to do with the type of heating element I use in the boiler ?! OK, leaving minerals and returning to the mash itself . . .
- One of the most crucial aspects of conducting yourself a mash is to get the "mashing in" step done correctly. Now, you can read all the books you like on this and they pretty much say the same thing . .. go mix the bejeebers out of the mash . . . if you don't then the mash will not be uniform in temperature and you will get unpredictable results. Well, fine, if you're a mega brewery and you're process is well sorted out and you can later separate the grain and sweet wort without much of a problem. However . . . . ever stirred the whatsits out of the mash only to see it settle down deep by the end of your 90 minutes and you then have to recirculate endlessly in order to clear the wort and . . . and . . . and ?! Thought so !
- You see, the books lead you down the garden path to a garden where no homebrewers in his or her right mind should ever visit ! WHEN MASHING IN THE GRAIN . . . DO NOT STIR LIKE A MANIAC ! In fact, add your mash liquor (& minerals) and let it stabilise in temperature. Then take a jug of your grain and sprinkle it gently onto the top surface of the mash liquor. Whatever you do, don't drop it from a dizzy height so that it goes crashing through the surface.
- Initially, when there's much more liquor than grain, the grain will quickly soak up the liquor and start to sink. However, as time goes by the mash becomes thicker and thicker and so the grain doesn't easily soak in and sink. Rather it sits pretty on top and will form dry lumps at every opportunity. Your job is to sprinkle the grain onto the surface of the mash and then GENTLY work it into the liquor. Some use a big spoon. I find that a set of barbeque tongs work great as you can squidge up those lumps fairly easily. In doing things this way you will create yourself a mash that looks like what the pros get. At the end of 90 minutes you should be able to open that tap and hardly have a need for recirculation. Serious, try it ! Its revolutionised the grain brewing of everyone I've ever known who did it this way. As you proceed through the mashing-in step, regularly give the whole mash a nice gentle "lift" by putting a spoon (or your tongs) into the grain and gently rousing the bed, stirring gently. This will help equalise the mash temperature.
- Part of the theory of such an approach to mashing-in is that the air pockets within the grain aren't entirely worked out of the grain during mashing-in. This creates the so-called "floating mash bed" and prevents your grain from settling too densely at the bottom of the mash tun. Instead it remains as a nice, uniformly spaced filter bed. There are of course potential problems this way. For instance, worry heads will tell you that the mash temperature will not start out uniform and they would be absolutely right. However, gentle and regular stirring as you mash-in can drastically reduce these differences. Also, your wort will be the sum of the parts of everything going on in the mash in any case and any differences will simply average out in the beer. Honest, I've been doing it this way for 5 years now without a problem. And so have most of our homebrew club. I do occasionally notice rather low sounding initial mash temperatures measured first off on the top of the mash but this is just the mash's way of telling you to stir a litle more to equalise temperatures or, if mash end temperatures are too low, you need to mash in a little warmer. Inevitably the mash will layer a little in temperature when you keep to minimal stirring but by mash-end its all sorted itself out through convection. And then some may worry that there is air trapped that will dissolve and oxidise their beer ... don't worry, its not an issue. If our beers were oxidised for this reason I think we would have known by now !
- Anyway, give this a go the next time you mash and if your mash settles too dense, gets set, requires loads of recirculation etc . . . then check your false bottom for oversized holes, or your malt for incorrect grinding. It just shouldn't happen if these aspects are looked after.
- In terms of mash temepartures, a mash starting temperature of 68°C will give you a fairly full bodied ale, I rarely let this go below 66°C for my ales. If your beers appear to have too rich a character then down this to as far as 63°C. They'll be more drinkable that way.
- Mash duration = 90 minutes. Yep, there's so much going on and so many starches that need converting that a full 90 minute mash when doing a single temperature infusion is definitely reccommended. Your run off shouldn't be even slightly hazy if you keep to 90 minutes . . . assuming of course the pH is OK and the temperature was indeed high enough for saccharification (big word describing how certain enzymes create fermentable sugars) and that you mashed in as described above.
- Typical mash end temperature = 63°C. This depends on your start temperature, mash duration, effectiveness of the insulation on the mash tun, how cold a place the mash tun stands in, whether or not you forget to seal the lid . . .
- Now I would suggest trying to keep your mash within the above conditions and to try not to over run. You see, there's a lot going on in your mash and times and temperatures can have a large effect. However, the upside is keep things pretty much constant from brew to brew and you shouldn't experience many problems.
OK, I've been fairly gentle on you so far in this section, no equations, just one diagram . . . and assuming that if you're still reading this the diagram didn't put you off, here's some info on what happens in your mash, probably only a small fraction of things but never-the-less a very important fraction !
The diagram explains how your mash will have two specific enzymes present, how they attack the starches and what their outputs are. Don't sweat if you don't like the look of it, brewers have brewed for millenia without knowing any of this. I'm just hoping that one day you'll look back and wonder what the heck you didn't understand about it the first time out !
Here's some extra info to help digest the diagram :-
- The diagram indicates that you have two main enzymes present in your mash at this temperature that are in anyway active. Most other enzymes have been killed off by the heat (denatured). I say 'most' because if I say "all" someone will email with a list of bullet proof enzymes that don't care a stuff about temperature ! Emails please . . .
- The first enzyme is called "ALPHA-AMYLASE" and is known to prefer conditions of around 70°C and pH of 5.6.
- The second enzyme is called "BETA-AMYLASE" and is known to prefer conditions of around 60°C and pH of 5.0.
- The alpha-amylase is very good at breaking starches into sugars called "dextrins". These are fermentable by yeast but at a slowish pace.
- The beta-amylase is very good at breaking starches into sugars such as maltose which is easier for yeast to ferment.
- So, the first thing to note is that by moving your mash temperature and pH to the preferred conditions for alpha-amylase you can create a beer in which a reasonable proportion of the fermentable sugars refuse to rapidly ferment out. Hence lots of residual sweetness and flavour components to give body, mouthfeel, pleasure etc.
- Also, aiming at the preferred conditions for beta-amylase sees a wort being formed that is capable of fermenting much further and so will produce a beer of lower final density, mouthfeel, body etc.
- So, if you've ever wondered why brewing books recommend a mash temperature of 63-67°C and a pH of 5.2-5.3 . . . go get your calculator out and average the preferred conditions for the two above enzymes.
- An additional insight the diagram brings is that beta-amylase is also capable of chewing away on the slowly fermenting dextrins to form maltose which is a faster fermenting sugar. So, as the alpha amylase produces the dextrins and you jump for joy at all the yummy flavours you're about to get in your beer, remember that over running your 90 minute mash will see the beta-amylase carrying on with the dextrin to maltose type sugar conversion. This will see you start with a high mash temperature but end with a thin beer. Keep to the 90 minutes mash duration . . .
- And finally, the diagram indicates how to control the enzyme activity simply by changing your mash stiffness. If you have a lot of mash liqour for your grain (say 3.0 litres per kg) then the enzymes can get into solution and move around the mash much quicker than if you have a low liquor to grist ratio, say 2.0 litres per kg. Its like taking a walk in water or mud, the thicker medium restricts your ability to move around. In the 90 minutes of your mash, control of the liquor to grist ratio provides an additional variable for you to control ! As mentioned elsewhere I often go for 2.3 litres per kg.
By way of summary though, keep life simple and when you're starting out on the mash approach, aim for a middle mash start temperature (say 66°C), a middle liquor to grist ratio (say 2.3 litres per kg) and if you can control pH go for 5.2-5.3. Having gotten your beer tasting along the lines you want it, in future change only the mash temperature in order to achieve different characters in your beer . . . its much easier than trying to change pH etc.
OK, that's all from me for now on mashing, hope you learned something !
And if you disagree with any of this email me, I can also do with learning some more !
