Thursday, 9 February 2012

Brewing at Aitken in the 1950's and 1960's

I was particularly pleased to find this particular reminiscence in the Scottish Brewing Archive's Falkirk edition. It's from Arthur Crumb, who was Production Supervisor for the 10 years leading up to the brewery's closure in 1967. Why am I so pleased? Because it's a description of the brewing process.

"Grain for brewing beer came from Linlithgow maltings. This grain was prepared for brewing beer by being spread on stone floors and rotated round these stone floors containing heat. The grain was then put in sacks and sent to the brewery, where it was stored in large bins.

The production and number of brews was decided every Friday. The materials and times for a production of a complete brew of beer from start to finish was then entered in the Custom and Excise book in the Customs Office at the brewery.

For each brew a grist line was made out for how many quarters of malt grain, flaked maize and rice. The grain was then weighed, put through a rolling mill - the rollers set so that the grain seed was cracked open (not crushed). This was then put into a mash tun hopper ready for mashing at beginning of a brew. A sample of this grist was taken when grain had been through mill and checked in the lab."
Scottish Brewing Archive Journal volume 4, 2002, page 14.

That's a pretty dodgy description of the malting process. But, as he wasn't a maltster, I'll let him off. One thing I'm learning: even though the barley might have come from anywhere in the world, the malting always took place in Scotland. Those were Aitken's own maltings in Linlithgow. And pretty substantial ones, as Bernard describes them (you can also see a picture of them above):

"Where is now the new range of malthouses and kilns, formerly stood the Main's Distillery, celebrated at the end of the eighteenth century for the special character and quality of its Lowland malt whisky. One of the old malthouses, the walls of which are of great solidity and strength, is still standing, and is utilized for its original purpose. It was in the year 1875, that the new maltings were built, under the personal direction of Mr. John Aitken, the present senior partner. They are most substantial four-storied stone buildings, of neat elevation, and possess a frontage to the meadows of 190 feet."
"The Noted Breweries of Great Britain and Ireland, vol. 2" by Alfred Barnard, 1889, page 189.

But that's enough of the maltings. I need to live up to the word "brewing" in the title. Let's move on to the brewery itself.

"Aitken's brewery had two mash tuns, one large, and one about quarter size of the large one. Large mash tun was for most beer brewed; small mash tun for making stout.

These mash tuns had close fitting brass plates fitted on the bottom with fine slits to let raw worts run through. To start a mash grist in hopper was controlled by feeding into a long funnel with a screw worm inside, this was mixed with hot water to a porridge-like paste. This mixture had to be kept at a specific temperature which was registered on a chart. From start to finish a mash was half-an-hour. The grist was then lifted up about four inches by pushing hot water through pipes in bottom of mash tun. This would have the mash sitting on top or supporting the mash.

After two hours we started running raw worts from the bottom of the mash tun. This was done by opening eight taps. This was then run into two coppers with steam coils in bottom. To keep the mash tun level hot water run at controlled temperature was sparged on top of grist to let it filter through grist into mash tun. When these two coppers were being filled and boiled up hops which had been selected and weighed, tins of malt extract, eight one-hundred-weight blocks of sugar (like tablet) were all added to the coppers then boiled for two hours and sampled. Gravity checked. These were then run into square hop back containers which had brass plates with fine slits. The raw worts was then pumped to another holding tank. This then ran through two parraflows; hot worts to one side of plates, cold water other side, and worts then came out at a reduced temperature. This was then pumped to selected fermenting vessels (tuns).
Scottish Brewing Archive Journal volume 4, 2002, pages 14 - 15.

Porter and Stout never reached the same dizzy heights in Scotland. Stout was a niche product for most of the 20th century. Which explains why it was brewed in a mash tun a quarter of the size used for other beers. They only made small quantities of it. Or perhaps, as some others did, they made it up mostly from ullage and returns.

By "Screw worm" he means a Steel's masher. I'm not going to explain again what that is, other than to say: external mashing machine. It would be odd, no downright weird, if they hadn't used one. The next bit is exciting. The bit about pushing hot water into the mash from below. He's describing an underlet mash. What does he mean by lift up? does he mean that it lifted the grain bed off the false bottom? I'd always assumed the point of underletting was to raise the temperature of the mash. Here it sounds more like it was to lift up the grain bed.

Two hours standing is pretty standard, though the odd brewery kept it down to just 90 minutes. Then they opened the taps and fly sparged. Fascinating stuff. Not really. The next bit is, though. See? The description of the copper. Heated with steam coils. That is, not directly fired. So pretty useless for kettle carmelisation. No surprise that sugar went in the kettle. The malt extract is more unusual. I've seen it in logs before now, but it didn't say where it was added. It's a shame there's no mention of how much. Because there's one reason I can think of for using malt extract: lack of mash tun capacity. That probably isn't the reason, though. My guesses are always rubbish.

Here's a break with Victorian practice: no cooler. The wort is going straight from the hop back to paraflow refrigerators. I wonder what happened to all the gunk that would settle to the bottom of the coolers? How did they get that out of the wort? (I worry about some weird things.)

This is getting a bit long. Best save some for part two.


Jeff Renner said...

Interesting that he says, "From start to finish a mash was half-an-hour." The two hours that followed the underlet he apparently considered to be separate from the mash. I would consider it all to be a step mash of 2-1/2 hours. The temperature of each rest would be of significance, as well as the thickness of each.

Gary Gillman said...

Ron, the hopback acts as a filter in that the flower hops hold back the trub. Also in this case, probably the liquid descended through those narrow apertures mentioned.

Therefore the wort coming out was probably pretty clear.


Martyn Cornell said...

I'm wondering - since Mr Crumb said the "grain" had come from Linlithgow maltings, which suggests it was already malted when it arrived at Aitkins (why would you buy raw grain from a maltings?) if he's not actually describing malting when he talks about the "grain" being "prepared for brewing beer by being spread on stone floors and rotated round these stone floors containing heat," but some kind of "opening up" of malted grain prior to it being ground: unlikely, I know, and probably he WAS trying to describe the malting process, but as you say, it's rather odd ...

Graham Wheeler said...

@Jeff Renner

In those days the mash referred only to the stirring action, the mixing bit, men with paddles or oars, to get a homogeneous mixture The mash referred to the first half-hour of vigorous stirring or the use of Armstrong rakes. The saccharification stand was a different issue. Today, we (home brewers) regard the mash and the stand to be the same thing, but in really it is not the truth.

Even with a pre-masher, like the Steeles; because a pre-masher was driven from a belt from a steam engine the pre-masher was immovable, so it dumped the hydrolysed grain into a big pile in the middle of the mash tun; the rakes were still necessary to flatten this pile into a level bed.

Some brewers, such as Bass, gave just three or four revolutions of the porcupine, whereas those brewers that were more fixated on tradition kept the porcupines running for a quarter to half-an-hour, to imitate the manual stirring.

Of course the underlet was routinely done for a different reason than raising the mash off the false bottom; that only occurred with a set mash.

Arthur Crumb - what a wonderful Dickensian name. If Arthur Crumb ever existed, he would have been a clerk; he would have worn a bowler hat, and the only time that he got his hands dirty was when wiping his arse. I would suspect that his knowledge of brewing did not extend more than six feet from his desk.

Mr. Crumb, if he really existed,is an unreliable witness, because he was reminiscing about his days at the brewery without really understanding what was going on.

Anonymous said...

The "spread on stone floors" bit comes before "put in sacks and sent to the brewery", so it does rather read as if it's malting being described and not some mythical "opening up" process.

Considering underletting as floating the mash up off the plates is a fairly common way of looking at things. Obviously, the underlet liquor does add some heating to the bottom of the mash, but it's also held to reduce the likelihood of a stuck mash.

Ron Pattinson said...

Graham, I'm sure Arthur Crumb existed - I have photos of him in a white coat standing next to brewing equipment.