is decoction mashing a big white elephant?

[critch]

ive never bothered, i dont have to, the malt i use is fully modified

heres charlie bamforths rather intresting take on decoction in modern brewing
http://www.brewersguardian.com/index.ph ... /1410.html

[Wolfy]

Interesting article, but focused (for obvious reasons) more on commercial brewing than home brewing, and most all of the disadvantages of decoction mashing that he lists much less relevant on a home brewing scale. Most home brewers do not have access (or want to use) "enzyme cocktails" or "jacketed mash mixers" which he suggests are the most viable alternatives to decoction mashing, but some do have HERMS/RIMS systems, which offer the home brewer the flexibility of "temperature ramped mashing".
For those without HERMS/RIMS (or other suitable method of step-mashing) I'd suggest that decoction mashing is still a viable option on a home-brew scale, especially if a home brewer chooses to use less (or under) modified Euro malt, in an attempt to emulate a traditional German lager.

On a commercial scale, both tradition and nostalgia are important factors, even if modern science tells us that decoctions are not essential, I can imagine some breweries not wanting to change their processes - but those who are not bound by those traditions or nostalgia using other techniques (which I thought many German lager brewers already did).

[alix101]

A decoction is generally not needed but like wolfy said can be helpful in creating some german styles...dunkel pils..etc .. budvar still do a an insane mashing process! yet there beer is great...yes it's a dying art for commercial breweries with modern malt but on a home brew scale can be rewarding and have interesting results.

[Lugsy]

Nice article, thanks Critch!

I would imagine that on a commercial scale the cost of equipment and the increased energy cost would be prohibitive, not to mention the additional time involved. For a homebrewer though I think it is an interesting technique that in my opinion can add a lot to a beer. I always decoct my hefeweizens (usually a double decoction) and I get a huge leap in efficiency but this alone isn't worth the effort - I could simply add another pounds worth of grain to get the same gravity. For me the flavour is the reason to decoct, the increased maltiness is just superb. I've tried using aromatic malt to get this taste but it's just not the same.

The article mentions the increase in DMS production using decoctions. This makes sense to me and I have to say that on a couple of occasions I've noticed a strong smell of DMS in the kettle after I've cooled and run off into the fermenter even though I've never noticed it in the finished beer. I'd assumed that this was down to the fact that my hefeweizens are only lightly hopped so this smell wasn't being masked by the huge hop aroma that's normally left in my kettle with other brews (generally very hop-forward beers) but now I can see that it's probably the decoctions that do this. I always boil for 90 minutes so I would expect the DMS to be driven off (and like I say, I've never noticed it in the finished beer) so this has puzzled me until now. Maybe there is some DMS in my wheat beers but the yeast masks it well enough for it not to be an issue, who knows?

[Graham]

I quick scan of the Charles Bamforth article indicates to me that it may possibly be confusing. It is easy to confuse decoction mashing with temperature-stepped mashing. They are not quite the same thing.

Decoct means "to boil". In a decoction mash about a third of the mash removed and boiled for 20 minutes and returned to the mash, which, of course raises the temperature of the mash. This typically occurs three times such that almost all of the mash eventually gets a twenty-minute boil. Although this process raises the temperature of the mash, the boil has another important function, and that is that it gelatinises the starch in undermodified malt, rendering that starch open to attack by the enzymes. That is why the boil is something like twenty minutes long - to give time for that to happen. Unmodified adjuncts, like rice and other grits, used in some countries, need cooking for this reason.

So the decoction mash is necessary for undermodified malt, and although undermodified malt is rare, unobtainable in Britain, some of the old Eastern Bloc countries still use it, probably as a matter of tradition, and I believe one or two French maltsters still supply the stuff.

The temperature-stepped mash, however, is for high nitrogen/protein malt, and there is still plenty of high nitrogen malt about - even in Britain. Indeed, the average nitrogen content of British malt is increasing. because most of the big breweries have a high-tech brewhouse, which features a stepped mash enabling them to get away with cheaper malt.

Things are not as straightforward as they were in the past. It was at one time an automatic requirement that malting barley was a low nitrogen product, having nitrogen content below 1.55% for pale malt and below 1.65% for mild ale malt. Sadly, today this is no longer the case. The ever-increasing demand for processed beers; tinned and bottled supermarket beers, nitrokegs and lager has had an effect on the quality of malt available. The brewers of these mass-marketed beers brew using a temperature-stepped mash and they chill and then filter the beer to remove protein. These brewers are not so bothered about protein for these processed beers and they can cope with cheaper, higher nitrogen food-grade barley.

Something like ninety per cent of beer sold today is processed, the result being that ninety per cent of the malt produced today ends up in these processed beers. The vast majority of brewing barley has up to 1.85% nitrogen content. Malt of this level of nitrogen can be utilised by high-tech brewers of processed beer, but it is too high for the single infusion mash brewing of traditional cask-conditioned pale ales. Only five per cent of malting barley meets the 1.55% maximum nitrogen requirement that we need. With the notable exception of Maris Otter, the malting barleys used today are the low-nitrogen fractions of general-purpose feed barley; they are not necessarily ideal for brewing using the traditional infusion mash. Other issues apart from nitrogen affect the suitability for traditional brewing techniques; buoyancy in the mash tun, drainage and run-off are affected by husk size and grain size among other things. These again are of less consequence to a high-tech brew house because the equipment can cope with it.

Even standard British lager malt has a relatively high nitrogen content and should be mashed with a stepped mash if optimum clarity is required if the beer is to be chilled before consumption.

[jonnyt]

Very interesting Graham. Following on what mash schedule would you recommend for a typical Bitter?

[Graham]

Very interesting Graham. Following on what mash schedule would you recommend for a typical Bitter?

As long as your pale malt is not unacceptably high in nitrogen content and as long as you are not going to chill the nuts off your beer, I am not suggesting that you do anything different from what you are already doing.

The point that I was trying to make was that Charlie Bamforth's article does not make enough distinction between decoction mashing and temperature-stepped mashing. It is easy to think that they are equivalent, as I did when I first started home brewing. The decoction mash is indeed obsolete, so obsolete that I find it difficult to understand why Charles Bamforth thought it pertinent to write an article about it. However, the temperature-stepped mash certainly is not obsolete. There is plenty of high-nitrogen malt about, even in Britain, and unless one is prepared to throw a cocktail of enzymes into the beer, as Bamforth advocates, then a temperature-stepped mash will be appropriate when using malt of higher than about 1.55% nitrogen, or beer that is going to be highly chilled.

[gregorach]

The only time I've resorted to decocotion is was specifically to increase DMS (I think a pils should have some detectable DMS, and I don't care what anybody says to the contrary), so it's good to get some confirmation that I was on the right track.