The Science
- Malt
- Use: Highest quality: Marris Otter, Belgian Pilsner, Vienna and Munich
- What are we trying to get? Melanoidins
- Formed by Maillard Reaction in kilning or during prolonged boils (4+ hours).
- Are Reductones - meaning they consume oxygen effectively stabilizing a beer with time.
- Resultant flavor compunds proportional to quantity in brew.
- Examples: Sherry, Maderia, Amaretto
- Rules
- Aquisition of Melanoidins: Use larger % of highly kilned malts and/or kettle carmalization
- Roast - use larger percentages to gain melanoidin compounds, not color
- Boil Times - approaching and exceeding 4 hours for lesser kilned malts, at least 90 - 120 mins for higher percentages of kilned malts
- Retain relatively high amounts of residual sugar (in all but Wild/Belgian)
- These sugars are reduced with oxidation creating the sought after aged flavor profiles.
- User of English yeasts provide for this
- Exception #1: Beers utilizing Belgian yeastt. HIgher phenolics associated with these strains substitute for residual sweetness in beers like Belgian Quad in aged flavor production. - Choose strain with highest phenolic output.
- Exception #2: Wild beers. Bugs are antioxidents and little oxidation will occur anyway. Aged wild brews result in different flavor development.
- Hops
- Only use hops with 1:1 alpha:Beta - noble hops: Saaz, Tettnanger, EKG, Hallertau
- Beta acids degrade slower and into compounds favorable in aged beer profiles.
- Alpha acids degrade to trans-2-nonenal (wet cardboard)
- Alcohol
- Min: 8%
- Hot fusel alcohols ok - they will mellow and add favorable flavor compounds
- Flavor compounds of aged high alcohols: sweet toffee, almond (aldehydes)
- Combining with Beta acids produces: fruit/winelike esters and if in a Stout with matured chocolate flavors can translate into black cherry
- ABV inversely proportional to Aging time, as alcohol is a preservative
- Wood
- Barrels fast track oxidation/aging
- Requires alcohol of plus 7% to have efficient extraction of compounds from wood
- Stays fairly stable through the aging process
- Do not use Caramel Malt if using wood. Caramel sweetness development will become cloying beside perceived wood sweetness
- Oxidation
- What - loss of an electron from an oxygen based molecuel to another molecule.
- ROS - Reactive Oxygen Species - the molecule that lost the oxygen, “oxidized”
- Results
- creates new molecukes when interacting with kilned malt molecules
- degrades alpha acids (negative effect)
- further develpos phenols and esters
- causing them to become the “dried fruit” version of their orginal selves. If plum, then prune, etc...
- forms aldehydes (almond, toffee, ameretto) from higher alcohols
Styles to Consider
- English Barleywine
- American Barleywine
- Imperial Stout
- Scottish Wee Heavy
- Belgian Quad (Belgian Strong Dark)
- Flanders (Red and Brown)
- Geuzes
The Beers
English Barleywine..Why it works
- High quality malt - Long boil time - high melanoidin creation
- English yeast strains
- throw big esters - plus oxidation equals flavor development
- produce high alcohols when stressed - plus oxidation equals flavor development
- attenuate relatively low, therefore residual sugar content relatively high resulting in sustained body as proteins reduce, slowing of oxidation process via reductones when combined with melanoidins
- Aging Expectation - 2 to 30 years
Imperial Stouts
- Water: Must target London (alkaline) water profiles to buffer against acidity which will cause off-flavors associated with autolysis next to roasted malt
- English Yeast strains produce same results as above
- Use of high percentage of highly kilned malts age well (Roast, chocolate, etc)
- Boil times do not need to be 4 hours as melanoidin content greatly achived through kilned malts - (Min 90 minutes, 120 better)
- Aging Expectation - 1 - 3 years before autolysis off-flavors begin to present
Belgians (Quad, big Dubbels)
- All the same as English Barleywine except use of Belgian Yeasts tend to a lower residual sugar result. This is ok, as the phenolics associated with Belgian strains favor positive flavor development.
- Aging Expectation - fresh is ok, optimum 5 years.
Other thoughts
- Bottle Conditioning is best
- Caps and corks are near equal in efficacy
- Ideal cellar temp is 10 degress below fermentation temp (55)
- Only wild brews may benefit from horizontal aging for first few years, otherwise vertical
- Use of melanoidin malt consider if not boiling long or using high percent of highly kilned malt