Tag Archives: colour

A Conversion Chart Between Beer Colour Scales

June 4, 2021 ak Leave a comment

In a recent Twitter discussion about beer colour and colour scales, Ron Pattinson said how handy it would be to have a conversion chart between colour scales, ideally for Lovibond, SRM, EBC, Stammer (famously used by Professor Schwackhöfer in his 1876 analyses of beers sold in Vienna) and “Einheiten nach Brand”. In particular, the discussion revolved around the latter, as it’s one of the scales used in TGL 7764, East Germany’s industry standard for beer.

TGL 7764 is a particularly interesting industry standard, as it’s a rare example of beer styles getting standardized down to original gravity, bitterness, beer colour and even beer label colour and (in the case of Porter) microorganisms (Brettanomyces). And unlike style guidelines nowadays, like BJCP or the Brewers Association’s ones, this was actually prescriptive, i.e. it was compulsory for breweries in the GDR to follow these beer styles. I’m not aware of any other country doing that, but then, I haven’t really looked into it systematically.

Unfortunately, there does not seem to be a linear relationship between the Brand scale and EBC, so a simple conversion based on a few data points that we have from the 1980 and 1986 versions of TGL 7764 (which uses NFE, Brand, K450 and EBC) is not possible. Nevertheless, I’ve looked at the conversion between Stammer and the other common scales in the past and even put a simple table in my latest book, so I took this as a chance to at least present the data that I already have.

I will try and find out more about the Brand scale and if I do, I will update this table accordingly.

Conversion Formulas

Stammer to Lovibond: °L = Stammer / 1.38

Lovibond to SRM: SRM = 1.3546 × °L – 0.76

SRM to EBC: EBC = SRM * 1.97

Conversion Table

EBC	SRM	Lovibond	Stammer
1.0	0.5	0.9	1.3
2.0	1.0	1.3	1.8
3.0	1.5	1.7	2.3
4.0	2.0	2.1	2.8
5.0	2.5	2.4	3.4
6.0	3.0	2.8	3.9
7.0	3.6	3.2	4.4
8.0	4.1	3.6	4.9
9.0	4.6	3.9	5.4
10.0	5.1	4.3	5.9
12.0	6.1	5.1	7.0
14.0	7.1	5.8	8.0
16.0	8.1	6.6	9.0
18.0	9.1	7.3	10.1
20.0	10.2	8.1	11.1
25.0	12.7	9.9	13.7
30.0	15.2	11.8	16.3
35.0	17.8	13.7	18.9
40.0	20.3	15.6	21.5
45.0	22.8	17.4	24.0
50.0	25.4	19.3	26.6
60.0	30.5	23.0	31.8
70.0	35.5	26.8	37.0
80.0	40.6	30.5	42.1
90.0	45.7	34.3	47.3
100.0	50.8	38.0	52.5

Beer Styles

Decoding the Colour of Historic Vienna Lager

November 18, 2018 ak 3 Comments

Back in 2015, when I started looking more closely into the historic specifications of Vienna Lager, one question where I started speculating and couldn’t really get a good answer was the question of colour. I based this off historic records that I had found in one of Ron Pattinson’s books, “Decoction!“. The provided value of “6.3” (no units) seemed reasonably close to be SRM, but as Ron commented below my posting, the beer colour is not in SRM, and that he’s not sure what exactly it is.

Well, today I can proudly proclaim that I have finally discovered not only what the “6.3” means but also how the value relates the modern beer colour units like SRM or EBC.

The whole thing started with me finding the original source for the specs Ron had put in his book. In fact, I had found these specs reprinted in several other books, as well, but all of them lacked information what the colour value actually meant. The original source is an article in Dingler’s Polytechnisches Journal, “Untersuchung der Biere, die in Wien getrunken werden” [Examination of the beers that are being drunk in Vienna] by Professor Fr. Schwackhöfer, published in 1876. Underneath the rather long list of analyses (which is great because it gives us other clues; I’ll get back to that), almost at the end of the article, it briefly mentions the system that was used to determine the beer colour: a system called Stammer’sches Farbenmaß.

From what I could find out, the Stammer’sches Farbenmaß [Stammer’s colour measurement] was originally developed to grade the colour of sugars in the sugar industry. It was in use from the 1870’s to as late as the 1930’s. Quite a few similar systems like that existed. In English-speaking literature, it was often called Stammer’s colorimeter. It worked by comparing the solution to be tested(or in the case of beer, just the beer) with a standard glass plate. It consisted of two glass tubes. One tube was filled with the beer (or sugar solution), while the other one was covered with the standard glass plate. Both tubes were illuminated from the bottom, and a prism at the top allowed the user to compare how both the standard solution and the glass plate looked like. You could then lower an glass immersion rod into the solution until the colour and shade most closely matched the glass plate. The measurement of colour was then the number of millimeters you had lowered the immersion rod into your solution.

The tricky thing with Stammer’s colorimeter is that there are two values you can work with. You have the direct reading, i.e. the number of millimeters of immersion, and you have the colour value, which is 100 divided by the reading.

A more detailed description of Stammer’s colorimeter as well as other systems of that time can be found in the Handbook of Sugar Analysis by Charles Albert Browne.

The next thing I then had to find was a way of converting readings from Stammer’s colorimeter to other units. The only source I could find was the brief article “Conversion Curve for Lovibond’s Tintometer and Stammer’s Colorimeter“, published in 1914 by Carl A. Nowak in the Journal of Industrial and Engineering Chemistry. This is great, because Lovibond is a well-known scale that has historically been used to grade the colour of malt and beer, and is apparently still in use to a certain extent to grade malt colour. The article contains a chart that shows the relationship between Stammer’s colorimeter and Lovibond values.

The Y scale contains the value of Stammer’s Colorimeter, while the X scale contains the corresponding Lovibond value.

What is noticeable in the chart though is that there is an inverse relationship between these two: higher Stammer values correspond with lower Lovibond values, and vice versa. But what is the Stammer value exactly? We have two available, the reading, and its inverse, the colour value. That’s where the comprehensive list of analyses comes in handy. Not only does it contain various pale lager beers, it also contains colour values of beers that we know are most definitely dark beers, in particular Salvator with a colour value of 41.5, and a bottled Porter with a colour value of 40. So from that we know that the higher the value was, the darker the beer was.

Since the chart indicates that the lower the Stammer value in the chart, the darker the beer, we can derive that the chart contains the Stammer colour value, while the values in the analysis are the direct readings, i.e. the amount of millimeters the rod was immersed in the tested beer.

To convert the 6.3 reading to the Stammer colour value, we simply calculate 100 / 6.3 = 15.87, and look up the corresponding Lovibond value in the chart, which is about 4.6 to 4.7. In modern units, this is equivalent to 5.5-5.6 SRM, or 10.8-11 EBC.

So there we have it, the colour of historic Vienna Lager. It’s paler than the usual beer style guidelines will say about Vienna Lager, but it fits what I’ve been saying for quite a while, that historic Vienna Lager was most likely paler than its modern versions, and that the usual beer style guidelines don’t capture the historic examples.

History, Malt

What was the colour of brown beer in the 19th century?

June 21, 2017 ak Leave a comment

When working on my upcoming e-book about historic beers, one particular aspect of recreating historic beers crept through my mind: how similar or different are modern malts compared to malts that were produced 100 to 200 years ago?

The biggest improvements in malting technologies, in particular kilning, happened in Continental Europe within the last 200 years: while smoke kilns used to be widespread, Bavarian breweries started adopting modern, smoke-free kilns about 200 years ago, and in the 1830’s, Gabriel Sedlmayr and Anton Dreher brought back more knowledge about how to produce pale malts from the UK back to Continental Europe. The 1840’s were the beginning of pale lager beers which eventually became the world-wide standard for mass beer production around the world.

But one particular aspect kept bugging me: what did the colour of brown beers use to be like 100, 200 years ago? Here, by brown beer, I mean all beer made from kilned malt. The romantic notion is of course a deep brown beer, made from a highly dried malt, almost bordering on porter. But how can we get closer to the truth? It’s not like we can just look up photos of beers back then. Or can we…?

Well, not photos, but there’s a similar source: let’s take a closer look at art of that time. If we assume that painters who focused on a certain realism in their paintings took care of getting their colours right, then we can expect a realistic and reasonably consistent portrayal of the colours of brown beer. So let’s go through a few examples.

This first example is from a painting depicting a Bavarian pub scene in 1855. One man holds a glass of reddish-brown beer with an off-white head. It’s not clear whether the glass on the table also contains beer, but if it is, looks slightly paler due to the smaller size of the glass.This example shows a Stammtisch scene from 1872 with the waitress handing the customer a glass of dark brown, almost black beer, with a distinctly white head.This picture from 1877 again shows a bright, reddish-brown beer, almost bordering on a dark amber. …and the same goes for these examples from 1885, 1888 and 1912. Noticeable in all three is a kind of glow, coming from a bright beer served in glassware, which, in my opinion looks mouthwatering. I would happily want to try one of these beers! The last two examples are slightly different: both from 1916, they show Austrian-Hungarian soldiers being served beer. The beer has an amber to golden colour, and is distinctly paler than in the other pictures that I showed here. Both are from brewery ads (the top one from the Hungarian Dreher brewery, the bottom one from Hütteldorfer brewery, Vienna), and mostly reflect the ongoing change in beer fashion at that time, while the previous examples are mostly from pictures painted by artists situated in Bavaria, where brown beer remained fashionable for longer than in most other places.

When we compare modern dark beers (in particular Bavarian ones) with those from 100 to 150 years ago, visually it seems like there is not really a difference. If anything, I’d say that the old beers in these examples may even have been a tad paler than the modern varieties.

Now what conclusions can we take from that, in particular for recreating historic beers? Well, the number one takeaway for me is that brown beers back then were mostly the same colour as today, which means that if I wanted to recreate an old beer recipe from that era, I could assume within reason that the colour of dark (Munich) malt nowadays is the same or very similar to how it used to be 100, 150 years ago. For historicity’s sake, the beer would also need to be as bright as on the pictures above: no haze in these beers. And finally, but that’s more of a minor detail: look at the drinking vessels at that time. While the Steinkrug (earthenware mug) is classically associated with historic beer of previous centuries, the art in the 19th century suggests that glassware must have been quite common for beer to be served in. And of course, a lot of the beer mugs have metal lids on them.

So, if you think about rebrewing some historic Bavarian brown beer, don’t worry about the malt, just use Munich malt as a dark base malt, and make the beer bright and haze-free, and you’ll be fine.