Decoction and other mashes

[iamthefly]

Hi, I've got some questions about mash, would appreciate some help:

firstly can anyone explain how /if decoction mash works? I read that it's supposed to impart a caramelised flavour due to the (I guess) Maillard effect caramelising sugars, but caramelisation doesn't start until

Sugar Temperature
Fructose 110 °C, 230 °F
Galactose 160 °C, 320 °F
Glucose 160 °C, 320 °F
Sucrose 160 °C, 320 °F
Maltose 180 °C, 356 °F

I can't see this being possible in boiling water unless you're heating it on a nuclear reactor core. Why not just add a slightly roast malt to the grain bill to achieve such a flavour?

All I can see it doing is raising the temp in stages like a step mash.

If I mash in a kettle, could I in theory achieve the same result as a step mash by raising the temp steadily and extremely slowly allowing the enzymes a chance to work at every temp?

If I'm more interested in lower ABV (I've got stuff to do) but maximising flavour, how should I adjust recipes/templates?

Lastly, what happens if I mash for longer than the usual 1 hour?

Thanks .

 

[Bigcol49]

Hi!
From what I have read, the main purpose of a decoration mash is to raise the temperature of the mash without adding extra water or heating the mash directly.
I have started using a hochkurz mash, with a very wet mash in a tea-urn boiler (3.5 to 4 l/kg), recirculating the wort and heating it directly. This has become popular with German brewers as it is faster and less bother than a decoration mash.
I extend the final stage (70C) to 45 minutes as it is thought to improve head retention; the total mash time, including mashout is 95 minutes.

 

[chthon]

The thing is, if your mash pH is correct, there is very little melanoidin formation. I did a couple of decoction mashes, one even for a weissbier. You wouldn't want to get that darker.

Does it add taste? Don't know really. It was fun to do this a couple of times, but I brew mostly on Friday evening, and I want to get over it in less than 5 hours, so I just use a simple infusion mash these days.

Second, for caramelizing you need at least a temperature of 110° C for caramelization of the fructoses, 160° C for the rest. You can't get that in the boil. The temperature of the boiling fluid is at all points almost the same, that is 100°C.

Extended boil times in brewing never were about caramelization or melanoidin formation (have a look at the blog "Shut up about Barclay-Perkins"). If brewers wanted to have a different taste and or color, they bought caramel and added it to the boil or at racking time.

 

[serum]

I've not tried a decoction but did some simple step mashes for my Belgian and French style brews and found it made quite a difference.The style of beer I was aiming for seems full at the start but dry in the finish. All the professional French and Belgian brewers do a step mash with quite a simple grain bill. Most brewing books are American and they swear by single infusions, even after studying practices of breweries that do the opposite.

I was finding beers done with a single infusion at 64 for an hour fermented well but they were a bit too thin. I went for 30 mins at 60C and 30 minutes at 70C and this seemed to improve the body quite a bit while still keeping them dry in the finish like they should be.

I've also tried a single infusion but boiling a portion of the wort down to a thick syrup but the step mash gave more of the right flavour even though both were quite nice beers.

Having said that, british ale doesn't seem to be done with a step mash but the character is different to the types of beer I'm trying to replicate. I wouldn't say there's a need to step mash it although it might be interesting to try.

I've just taken the plunge and bought a Braumeister so I can step mash away to my heart's content and hopefully I'll be able to get closer still to the beers I enjoy the most.

 

[Dr_Unkenly]

I have not done a decoction mash myself but I have read Randy Mosher's book 'Radical Brewing'.

He talks about decoction mashing being used as a historical practice primarily to allow step mashing to be done using the equipment available at the time.

Now your beta glucan rests and protein rests are not usually things we bother with these days but they were beneficial when using the less modified malts that they had in the days of yore.

He also states that the boiling in decoction mashing does add a certain amount of caramelisation to your mash. This makes sense to me, after all, how do you make caramel? You boil sugary water in a pan.

As you have said, why not just use crystal malt instead?
Well, that's what most people do these days but according to Mosher, you don't get quite the same rich flavour as you would with a decoction mash.

 

[chthon]

When starting from sugar and water to make caramel, what you will end before you get to caramel is molten sugar. The water will already be vaporized before the mix will get hot enough to form caramel.

Now, in decoction mashing, you will never get to that point. The malt will scorch before that point.

Also, if you want to reliably increase the temperature of the main mash it is better to not have too much vaporisation, because the wort is better for this than the malt.

Now, with respect to step mashes. I did say I use a single infusion mash, but in practice I indeed always do a step mash of about 64-67° C, and then I increase the temperature to 70° C for half an hour. This is a step mash, but it is single infusion: I only use water to mash in. I brew smaller quantities than most people, and I use a stock pot of 10L on my electric furnace. This works well for me.

 

[Dr_Unkenly]

The word Mosher uses is 'caramelisation' and he quite enthusiastically talks about decoction mashing imparting both a darkening of colour and a unique version of caramel/malt/nut flavours critical to authentic versions of certain styles.

Did he misuse that word to mean 'maillard reactions' (as in caramel) rather than 'cook sugar' (as in dark candy)? I don't know, but the important thing here is that the process has the potential to alter the flavour of the finished beer.

Now, I can see there are almost limitless different ways of decoction mashing and presumably one can do it in such a way that it does little else than adjust the main mash temp but there are also a range of flavours and colours to be unlocked using variations of this technique.

This all seems like such a rabbit hole to go down (22 step decoction in the traditional pilsner recipe, what?) and there seem to be enough of them in brewing already so right now I would look at things like crystal or Munich malts to get more 'malty' type flavours in my beer before looking at esoteric mashing techniques.

 

[chthon]

I found it an experience to have done it. But you must really plan yout brewday well, best prepare your malt and water the evening before. Put every step on paper so that you know what to do next and what to take into account. You need two heat sources, or one heat source and well isolated pot. Always take more out than you need, so you are certain to get to the correct temperature in one go.

 

[Dr_Unkenly]

If nothing else, you certainly earn your home brewer's badge of honour there, chthon!