Sunday, 12 October 2014

German brewing in 1960 - mashing and boiling

No, I hadn't forgotten. Just busy with too many things at the same time. Most of it Lager connected.

This type of brewer's report always fascinates me. They're useful, too, with a concise account of a country's brewing methods. That it's all about Lager is a plus.

On a totally unconnected note, I've a couple of Lager projects planned for next year. I hope they work out. It will be something no-one has ever seen before. And some of the information in this JIB article will play a role.

Anyway, back to German brewing in the time of the Wirtschaftswunder, starting with mashing:

"Brewing.—In a particular area there tended to be some conformity in the beer types produced and the mashing procedure adopted. All-malt mashes were enforced and again a common liquor treatment was to soften with saturated lime-water in the cold, then adding gypsum or calcium chloride in an extension of the softening apparatus; more simply, the gypsum was added dry to the grist. The flexibility of the process, whereby various beers of distinct character are produced by variations in the mashing procedure, is shown in Fig. 1, where the average mashing conditions for three typical pale beers are grouped together, ignoring the decoction details. This clearly underlines the desirability of obtaining good mash proteolysis where a full-drinking beer is required, the temperature chosen for saccharification being in rather closer agreement for each type."
Journal of the Institute of Brewing, Volume 66, 1960, page 499.

It strikes me as random what is and isn't allowed according to the Reinheitsgebot. Why could you add gypsum to the mash? Unlike filtration agents, it will be present in the finished beer. So how come it doesn't count as an ingredient? I can sort of see the argument if the water is treated before brewing, but when you add it directly to the mash? That's taking the piss.

The diagram demonstrates nicely the difference in mashing techniques for different types of beer. The Pilsner scheme looks like Hochkurz (high short) mash. It's what was normally used for Pilsner as a standard decoction could add too much colour. Not sure what that Dortmund method is. It seems to have a lot of steps in it.

Here's a bit more about mashing:

"Six-roll mills with vibrating screens predominated, and regular grist analyses were performed to maintain the correct grind, which was considered particularly important with regard to lauter-tun filtration. The mash was made either by dropping the grist dry into the prepared length of liquor in the tun, or by mixing grist and liquor externally in a vortex pre-masher and making up with liquor to standard dip in the tun. Two decoctions were usually made for pale beers and three for Munich, about one-third of the mash being decocted in each case, with the actual quantity dependent on the temperatures required."
Journal of the Institute of Brewing, Volume 66, 1960, page 499.

That's a bit vague on decoction details. Two decoctions for pale beers? Didn't the Dortmund scheme in the diagram have three? By "Munich" I'm pretty sure he means Munich Dunkles. I wonder why that got an extra decoction? Possibly tradition. A description of the Munich method of mashing by Julius Otto, published in 1865 (when all Munich Lagers were dark) specifies a triple decoction.

Now something about the brewing kit employed:

"Two breweries in Dortmund which suffered from shortage of space had installed block brewhouse units. These were of different designs, but in each case the block unit consisted of mash and decoction vessels mounted above the copper, with the mash taken off to a separate mash filter.

Brewing plant in Bavaria usually consisted of the traditional double brewhouse with 4 vessels — mash tun, mash kettle, lauter tun and wort kettle. New plant tended to retain the lauter tun in preference to the mash filter, even in large breweries, although it was admitted that, with a poor malt, filtration could take over 6 hr."
Journal of the Institute of Brewing, Volume 66, 1960, page 499.

Six hour runofff - sounds as bad as having loads of oats in the grist. Four vessels? I though traditional Lager breweries had two? Have I been missing something.  or have I only seen smaller, simpler breweries?

Block brewhouse units? What the hell are they?

"Boiling was usually vigorous although fountain spreaders were not used, and the hop rate varied from 7 oz. per brl. for the voll-bier type to 13 oz. for Pilsner. Plant for hop- and hot-trub-separation was generally two-fold, as in Denmark. Traditionally the trub was allowed to settle out on the coolship after the hops had been strained off, the bright wort was decanted and cooled on open horizontal refrigerators and the trub wort filtered on a press with cloths. Although slow and open to infection, this process was still prevalent in Bavaria, but newer plant in the North replaced the coolship by an enclosed stainless-steel tank, and trub wort filtration was then either by self-emptying centrifuge or through kieselguhr. Plate cooling was then employed, although the filtered trub wort was usually re-sterilized before being cooled and mixed with bright wort."
Journal of the Institute of Brewing, Volume 66, 1960, page 500.

Oh great, something specific about hopping rates. You can see how low they are if you compare them to Whitbread's:

Whitbread beers in 1960
Date Beer Style OG FG ABV App. Atten-uation lbs hops/ qtr Hops oz/brl
2nd Mar Best Ale Mild 1030.6 1010.0 2.73 67.32% 5.67 11.14
1st Mar FB Brown Ale 1033.3 1009.0 3.21 72.97% 5.25 11.24
2nd Mar KKKK Strong Ale 1051.8 1016.0 4.74 69.11% 7.50 24.88
10th Jun PA Pale Ale 1038.6 1012.0 3.52 68.91% 5.89 14.56
29th Feb WPA Pale Ale 1035.5 1008.0 3.64 77.46% 8.63 19.97
Whitbread brewing record held at the London Metropolitan Archives, document number LMA/4453/D/01/127.

Pilsner was barely more heavily hopped than sub-3% ABV Mild. The only Whitbread beer of a similar gravity to the Lagers, KKKK, has double the hops. At this point British beers were no longer particularly heavily hopped. My conclusion is that German Lagers were very lightly hopped.

I've seen plenty of open coolers in small German breweries. Annoying that the author calls them "Coolships" again. One of the reasons coolers continued to be used after other cooling methods were invented was because of the gunk that settled out when wort was in them.

Now here's something I've not come across:

"One novel process was seen which employed a system of wet grinding. Malt was washed and pre-soaked in cold liquor for 10-15 min. before being passed through a single pair of crushing rollers along with the actual mashing liquor. The grain was thereby merely squashed, the husks being undamaged, and this was said to facilitate lautering. This apparatus was built into a fully automatic remote-controlled brewhouse which has now been in successful operation for 4 years."
Journal of the Institute of Brewing, Volume 66, 1960, page 500.

Crushing soaked grains sounds totally crazy. I wonder what sort of yield they got with that method? I'd be worried about leaving lots of goodness in the grains.

Next time it's fermentation.


Ed said...

The reinheitsgebot is odd. I think if something could be naturally present in water, like gypsum, you're allowed to add it, but if it wouldn't be, like lactic acid, you're not. But I could be wrong. They don't exacly publicise what's really in the reinheitsgebot do they?

Wet milling is still around, it's mentioned in the write up of a brewery in the latest issue of the IBD mag.

Rod said...

"Not sure what that Dortmund nethod is. It seems to have a lot of steps in it."

Rests at approx. 100, 122, 149, and 162 F are typical of a complex, multi-step mash, which is what this is.

Barm said...

A "block brewhouse" or Blocksudwerk is an arrangement where the different vessels are all enclosed in the same insulated enclosure, with the pipes etc running through the insulation.

The 1930s brewery in the animation ( that you posted a few years ago had a four-vessel system: Maischebottich, Maischepfanne, Läuterbottich and Würzepfanne. You pump the mash from the Maischebottisch into the Maischepfanne to boil the decoction, then pump it back again. This system obviously has a great deal of redundancy but it presumably means you can get on with the next mash while you are still boiling the wort in the Würzepfanne. Smaller breweries can get away with using the same vessel for boiling the decoctions and the wort because they don't have to brew so often.

Jeff Renner said...

I often temper the malt by wetting it and letting it sit for an hour or so. It toughens the husk and keeps it from tearing and shredding. Makes a better filter bed.