A couple of comments about yesterday's post have prompted me to investigate roast barley, patent (black) malt and roast malt.
In "Guinness's Brewery and the Irish Economy 1759-1876" by Lynch and Vaizey 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" by S.R. Dennison and Oliver MacDonagh 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 shall not be lawful for any Brewer to have in his or her Brewery, or in any Part of the Premises connected with his or her Brewery, any raw or unmalted Corn or Grain" -- Duty on Malt (Ireland) Act, 1813 (section 10). (Thanks for this quote, beer nut)
It seems to me that:
1. Irish brewers weren't allowed to use unmalted barley in the early 1800's
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 started using roast barley.
Going back to "A Bottle of Guinness Please" by David Hughes I think I've found the answer. On page 74 it says that in 1972 the Guinness Park Royal brewery in London brewed extra Stout from a grist to 70-71% malted barley (I uppose it means pale malt) 9-10% roast malt and 20% flaked barley. On page 75 it gives the 1983 Park Royal grist - 60% pale malt, 30% flaked barley, 10% roast barley.
The bjcp say this of "dry" Stout: "The dryness comes from the use of roasted unmalted barley in addition to pale malt, moderate to high hop bitterness, and good attenuation." So I suppose pre-1980's Guinness wasn't true to style. I wish I'd known that at the time. Then I could have marked bottle-conditioned Guinness down.
Until yesterday I had assumed that Guinness had been using roasted barley for centuries. Once again, how wrong I was.
Zythophile has dug up even more interesting information about early Guinness grists in Bristol-fashion Guinness and the roast barley question.
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