Beer styles

To those who wait?

Whereas the best lagers have a month, two months or even longer to mature, some big industrial incarnations, we understand, are lucky to get three days.

Given that the purpose of lagering is to allow chemical compounds to dissipate or be consumed by the secondary action of yeast, how is it actually possible to accelerate this process? More chemicals? Sorcery?

Peraps all the important stuff happen in the first three days and the rest is just superstition and marketing, but we can’t help but wonder if is this one of the reasons why, say, Stella Artois tastes so nasty.

Would it improve if given 90 days to ripen?

18 replies on “To those who wait?”

Perhaps the proper lagering time is one of the reasons why Budvar remains one of the world’s great lagers, 12 days primary fermentation followed by 90 days lagering. 1 week for every degree Plato, as was the standard in the past.

Via Twitter, we’ve been sent this link by @stringersbeer

Digesting it now but, in short, one answer seems to be genetically modified yeast which doesn’t produce diacetyl. Lumme.

No breweries use genetically modified yeast, though there is a commercially used enzyme from GM bacteria that speeds up diacetyl removal.

And also on Twitter, @evanrail said: “On Czech beer: you don’t do 90 days of lagering because you’re noble and heroic. It’s because your yeast strain produces a ton of diacetyl.”

Dunno, I’m not sure a warm diacetyl rest and an long cold lagering time are doing the same thing. I’ll have a look at the text books when I get home but I think the long lagering is for a more general not just diacetyly related flavour improvement.

Ed — have a feeling your right, based purely on the fact that beers that have long lagering times tend to be better than those that don’t, so there has to be *something* else going on in those 90 days.


Check out Morton Coutts and continuous fermentation, this could be the answer, it’s certainly the reason why big brewery lager in NZ is rubbish…

Of course the “proper time” would most likely vary from yeast strain to yeast strain and the the flavour profile desired by the brewer. When we brewed the Trukker Ur-Pils at Devils Backbone, we used the Augustiner strain, lagered for 30 days and it was a delight.

So, answers so far:

1. industrial processes which prohibit formation of diacetyl and reduce it more quickly than lagering
2. use of yeast strains which produce less diacetyl and other undesirable flavour compounds, or which need less lagering time to deal with them.

I’m a great proponent of lagering (and not every great Czech beer has 90 days), but I must admit to being flumoxxed last year at Pivovar Modra Hvezda when the brewmaster Petr offered up a taste of his 16˚beer straight from the tank — it was full, smooth and deliciously bitter in the finish, delicious. How long has this been in here I asked. Three days came the answer…though looking at my notes I think it could have had up to 50 days before being released into the community.

ATJ — another example of where science and superstition are hard to separate?

(When we lagered at home, our temperature was all over the shop, and the beer still tasted pretty good (to us) after about 20 days.)

Can it be that many macro lagers are brewed using HGB (High Gravity Brewing), are also highly attenuated and then diluted with water, this, and the fact that some of the adjuncts used produce high fermentable sugars, doesn’t leave much for the yeast to work with in the secondary fermentation?

I remember a couple of years ago when at a micro near Hradec Králove the owner and brewer gave me to taste the same beer with 14 days and with almost 90 days lagering. They were quite different, the younger one was still quite nice, but it left a mild, green banana flavour that I’ve come to associate with lagers that haven’t been given enough time.

@Ed, the link I found was to an academic paper – I have no idea if any brewer (anywhere) uses GM yeast – I believe there are a couple of yeasts with UK approvals, but I suspect that the EU would require labelling.

I’ve read that immobilised yeast is used by brewers in processes which, under carefully controlled conditions can reduce maturation of “lager-style” beers, to days (hours?) rather than weeks. Of course, that’s maturation measured in terms of the things industrial brewers are (a) tooled up to measure and (b) give a toss about. A Diacetyl rest (raising the temperature towards the end of primary fermentation) is, I believe a fairly common trick used to reduce the time required in “lagering”, at least as far as diacetyl reduction goes.

But hey, I’m only a bit of an ale brewer.

A number of GM yeasts were developed, and one was even cleared for food use by the authorities in the UK, but none have been used commercially because as Boulton and Quain put it in “Brewing Yeast and Fermentation”: “Against a background of consumer concern coupled with a highly competitive market, such an action would be tantamount to commercial suicide!”

The same authors have the following to say on lagering which explains a lot about it, but not much on how to speed it up:

“The secondary fermentation is performed in closed chilled ‘lagering’ tanks. This process may last from a few weeks up to several months. Typically the beer is run into lagering tanks at a temperature of roughly 5 degrees C and over a period allowed to decrease to 0 degrees C. Occasionally a more rapid treatment lasting just a few weeks at -1 to 0 degrees C may be practised. If the secondary fermentation is too sluggish, additional fermentable extract and yeast cells may be added in the form of actively fermenting wort, a treatment known as krausening.

The conditioning process has three functions: adjustment of carbonation, full development of filterable chill haze and final flavour development. The flavour changes encompass a multitude of complex reactions. These range from simple CO2 gas stripping of volatile components such as acetaldehyde and H2S, through to the production and removal of desirable and undesirable flavour-active by-products of yeast metabolism. Of vital importance during this stage, remaining acetohydroxy acids spontaneously decarboxylate to form undesirable vicinal diketones, in particular diacetyl. Yeast cells must be present to reduce the vicinal diketones to much less flavour-acitve diols.”

Thanks Jon and Ed.

Another question: given how cagey the big brewers are about revealing their lagering times, is there any evidence to suggest that any of them are really only lagering for three days? Or is that a total myth?

If it is happening, it sounds like it would be a real technical feat to pull off.

So he did. So *really* rough stuff gets days and it shows; while the middling, only-slight-nasty stuff gets a bit longer?

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