Thursday, 1 November 2007

Irish Porter, London Porter

I was gutted when the Guinness archive told me that they don't let anyone look at their brewing records. How was I ever going to get evidence about Irish Porter and Stout. How did they differ from their London cousins? Was there a difference, other than mere strength, between Irish Porter and Stout?

I was beginning to accept that I might never get answers to these questions. The archivist had suggested I try looking in the two histories of the brewery ("Guinness 1886-1939" by Dennison & MacDonagh and "Guiness's Brewery in the Irish Economy 1799-1876" by Lynch and Vaizey). As it happens, I own both. And neither has details of the compostion of their beers.

Along with a no smoking section, it was the bookstall at last weekend's Bokbier Festival that interested me most. I've told you my weakness for beer books. When we buy a new bookcase there won't be piles of them on the living room floor any more. At least for a while. The stall had a couple of Dutch brewery histories that I didn't own and a big glossy volume called "A Bottle of Guinness Please" by David Hughes. It looked like a compilation of old Guinness advertising from the cover. But you never know, so I flipped through its pages. I found a few of the thing I most love - tables of numbers - so reckoned it was worth 40 euros of my money.

It was only when I had chance to peruse it more dilligently at home that I noticed what was on pazge 71. The malt bills and hoping rates for all Guinness's beers in 1883. Words cannot convey my joy. Obviously someone had looked at the brewing records.

I'm a generous type. I don't keep this sort of stuff to myself.

It was sort of what I expected. Mostly pale malt with 5% roast malt for colour. Though I hadn't foreseen the 10% amber malt. Sure enough, no brown malt at all was used. The similarity of the grists for Porter, Stout and Export Stout didn't surprise me either. Breweries liked to keep things simple in the 19th century.

Some claim that the difference between Irish Porter and London Porter was the use of roast malt. As you'll see from the tables below, this doesn't appear to be the case. Some London brewers used black malt for colouring, others also called roast malt. But they They all used brown malt. Whitbread were still using it in the 1950's.

To answer another of my questions, there's no significant difference between Guinness Porter and Stout, except that the latter was more heavily-hopped.


Anonymous said...

I'm a bit confused by your roast/black malt terminology. By the "roast malt" in Guinness do you mean roast barley? Where I come from roast malt and black malt are the same thing.

Ron Pattinson said...

Lachlan, good question. Before 1880 I'm pretty sure that unmalted barley wasn't allowed.

In the London logs, for some breweries it's "black malt" others just "roasted". But it is very consistent over decades - the breweries either used one or the other.

I haven't seen the Guinness logs myself, but I'm pretty sure in "A Bottle of Guinnes Pleas"that it says "roast malt". I'll check later today.

Stephen Lacey said...

I was going to make the same comment as lachlan. I haven't made many stouts, but the one I most remember followed a recipe from the Michael Lewis beer styles book. It was a cracker and won a 1st in the stout section of a home brewing comp. Interesting in that I don't really like stout all that much. It certainly went for the roast barley, so I wonder when adn where that came to be so strongly associated with stout, especially so-called "dry" stout. I think it would be fascinating to brew two otherwise identical stouts, but one with roast (black patent?) malt and the other with roast barley. I think I'd prefer the one with roast malt.

Ron Pattinson said...

Mmm. I'm now starting to think that I may have been wrong in thinking roast malt and black malt were different.

I really have to check the Guinness book again to make sure it does say roast malt.

The invention of black patent malt was prompted by the strict imposition of a sort of Reinheitsgebot in Britain in 1816 (if I remember correctly). It meant that only malt could be used to colour Porter. The rules were relaxed a bit later on - sugar was allowed in 1860-something - but adjuncts like maize only became legal in 1880.

I'm not sure if these rules applied in Ireland.

I guess the association of roast barley with Stout comes from Guinness.

I really like the taste of brown malt in a Stout. Lachhlan brewed a cracking version of Barclay Perkins IBSt where the brown malt really had an impact on the flavour (at least to my uncultured palate).

I would love to find out which malts other Irish brewers used. It wouldn't surprise me if they differed quite a bit from Guinness. Now I wonder if Murphy's and Beamish have kept their brewing records?

Ron Pattinson said...

In the Guinness book it does indeed say "roast malt".

This is what is says about malt in the text:

"Guinness started using brown malt but made an early breakthrough when they began heavily roasting malted barley to produce Patent (black) malt for this purpose."

That seems to confirm that roast malt is patent malt and that Guinness used it and not roasted barley.

It's not obvious what the source is for this information.

Anonymous said...

"I'm not sure if these rules applied in Ireland."

I thought the very reason that roast barley came about was precisely because Ireland DIDN'T have those rules. But I have no idea where I read it - might've been the same person who says Scottish beers aren't hoppy because Scots are tight-arses. :)

Ron Pattinson said...

Lachlan, I need to do some digging into what the rules were in Ireland.

OK, I've taken a look in "Guinness's Brewery and the Irish Economy 1759-1876" and it says this (talking about the early 19th century) on page 158:

"For example, roasted barley was a good substitute for roasted malt, but its use would have evaded the excise on malt."

This is from "Guinness 1886-1939" page 11 (again talking about the first half of the 19th century:

"The brewing processes changed little over the century. It is necessary to go back to 1819 to find a mildly revolutionary change in the introduction of 'Patent Brown Malt'."

It seems to me that:

1. Irish brewers weren't allowed to use unmalted barley
2. Guinness used roast or patent malt
3. Guinness was an early adopter of patent malt - Whitbread didn't use it until several decades later

This has left me wondering exactly when Guinness srated using roast barley.

Matthew D Dunn said...

You say that most London brewers employed brown malt into the 1950s, in addition to darker malts or roast barley for color. I would love to know how the amount of brown malt in grists changed after the introduction of the saccharometer. Mathias seems to think it was a fairly dramatic shift away from brown malts because people realized that it was much less cost effective to brew all brown malt beers than to brew pale malt beers with some highly roasted grains to give the beer its porter-esque character.

Also, beer styles don't exist. So it's hard for the BJCP to "get them wrong."

Ron Pattinson said...


you can see for yourself how London Porter grists changed in the 19th century:

Interesting point, negating beer styles. Have any particular arguments?

Unknown said...

"I would love to find out which malts other Irish brewers used. It wouldn't surprise me if they differed quite a bit from Guinness. Now I wonder if Murphy's and Beamish have kept their brewing records?"

The Murphy's records are publically available- see