Category Archives: Diacetyl

Lager, Lager, Lager

When some very enterprising German brewers decided to store their beer in the frozen Bavarian Alps through the summer time in the early nineteenth century, little did they know of the impact there new “Lager” creation would have on the world of beer.  Some of these brewers were so moved by the potential of this wonderous brew that they started to leave their Bavarian breweries to spread the word around Europe and refine this new brewing art.  Many on the continent were so moved by the potential of Lager and the Lagering technique that many brewing enterprises started making related products of their own giving rise to styles like the Red Lagers of Vienna.  Much credit also needs to be given to Bavarian brewer Josef Groll who, in 1842, took the brave step of heading to a little-known brewing town called Pilsen in the Czech Republic to try out his new lager recipe.  Following on from this original Pilsner (Pilsner Urquell), innovations and developments in the likes of glass bottle manufacture and refrigeration coupled with a good helping of migration meant lager quickly became a worldwide success.

Lager is as popular as ever and whether its Pilsner, Helles, Vienna Lager or Schwarzbier you are considering brewing, Murphy and Son is the place for everything you need for a flavoursome quality lager.

Liquor Treatment

Our much treasured, annual free of charge liquor analysis now includes a suggested liquor treatment for lager style beers as standard.  If you have not had you liquor checked for a while and you are a Murphys customer please send 50ml of untreated water to our lab for us to check out for you.

Our suggested lager treatment aims for a brewing liquor with adequate calcium for good brewing enzyme activity, yeast flocculation and oxalate and protein precipitation whilst mimicking the low sulphate and chloride levels of Munich and Pilsen for a crisp, light flavour.  This is best achieved with suitable additions of lactic acid to reduce alkalinity with low levels of calcium sulphate and calcium chloride to increase calcium ions.


Our new closer ties with Simpsons Malt means that we now have in stock ready for dispatch Finest Lager Malt (crushed).  This highest quality malt is slightly higher in Total Nitrogen and slightly under-modified so head / foam and mouthfeel will survive the lagering process. To add to this quality base malt, we can also supply a range of crystal malts, caramalt, wheat malt and Vienna malt (all crushed) direct from our warehouse.


Whether you are looking for traditional varieties of Noble Czech Saaz and German Hallertau hops, or looking to add a dry hop twist to your brew with new world hop pellets, we are very proud of our close relationship with Charles Faram which means we can supply the best hops around to suit your requirements.


On the dried yeast front we are pleased to hold stock of Lallemand Diamond Lager Yeast and three different Fermentis Lager Yeasts.  We also supply wet yeast cultures from the National Collection of Yeast Cultures (NCYC) which houses a vast range of lager strains originating from all over the world which can add the precise character you are looking for.

Flavour control

Diacetyl and Sulphur flavours can be problematic in lagers to help keep things under control we have the perfect products to help.

When added to wort at the start of fermentation, the enzyme Alpha Acetolactate Decarboxylate (ALDC) acts on the diacetyl precursor alpha acetolactate converting it to acetoin.  If alpha acetolactate is not present diacetyl can’t be formed so no buttery off flavours in your beer and conditioning time can be reduced.

To help keep sulphur off flavours out of your beer, Murphys have developed two zetolite products for the job.  Zetolite 65, when added to wort at the start of fermentation will prevent the formation of sulphur off flavours whilst if you notice the undesirable sulphurous aromas in your fermented product, the addition of Zetolite 63 will stimulate your yeast to reduce H2S and DMS aromas during maturation.

Don’t forget…

…an exuberant bright appearance is important with lagers and at Murphys we carry a huge range of finings and stabilisers to help achieve the desirable crisp look from brewers clarex to Super F, Silica and PVPP products, the Murphys Technical team is on hand to get this just right for you.  PGA is also a handy product to help achieve a perfect looking head on dispense.

For further information on any of the products discussed or for general advice and trouble-shooting with lager brewing please contact the Murphys Technical Team.

We Sell Key Kegs!!!!

Author: Iain Kenny, Technical Sales Representative, Murphy & Son Ltd

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Diacetyl Control: Using ALDC to brew the beer you intended

What is ALDC? Alpha acetolactate decarboxylase.

Benefits of ALDC:

·        Reduces Diacetyl production
·        Significantly reduces maturation times
·        More efficient vessel utilisation
·        Improves beer quality

Diacetyl is well known among brewers and beer drinkers – distinctive for its buttery aroma and flavour. It is both produced and removed naturally by ale and lager yeast strains alike during the course of a typical fermentation and many reliable house yeasts leave a little residual diacetyl in the finished beer. As such it is fairly common with many traditional and popular beer styles to contain some level of diacetyl in their flavour profile.

Murphy and Son has worked with a number of craft breweries in the USA and United Kingdom who wanted to produce modern, hoppy pale ales without any flavour of diacetyl, but that was brewed using their existing house ale strain of yeast. The concentration of diacetyl was initially monitored to see how it was being lowered by the breweries controlled fermentation and how effective the yeasts own ability to reabsorb and reduce the diacetyl during maturation was.

Murphy and Son analysed this beer for diacetyl levels in their laboratory in Nottingham, England. It was found that by applying ALDC to the wort at the same time as the yeast was added in a concentration of 3 to 4 grams per hectolitre, the flavour would be brought below threshold in the finished beer as desired (figure 1).


ALDC is commonly used in lager production to lower maturation time, the rate-limiting step, by converting acetolactate (the precursor of diacetyl) to a flavourless end-product called acetoin. (figure 2 below).


In this instance the ALDC was able to boost the diacetyl lowering effect of the yeast in the same way, culminating in the desired low concentrations of diacetyl in the finished beer and allowing the brewer to broaden the spectrum of beers produced without the need for another yeast.

As ale fermentations are much faster a little more ALDC was required than may be needed for lager, but at 3 to 4 grams per hectolitre of ALDC it was still found to be an economical solution to the brewer.

Murphy and Son Ltd sell ALDC in 1kg pack sizes!