The Radial Rays (correctly multiseriate parenchyma rays) their large size is almost unique to oak

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1 The Radial Rays (correctly multiseriate parenchyma rays) their large size is almost unique to oak the tree s food storage area they are packed with tannin The latewood rings (grow in summer, always larger than the earlywood rings) high in fibres, a major source of lactones, tannins are harsher than in the earlywood because of limited penetration of the wood by fungi during seasoning 1

2 Tyloses stop the stave from leaking not relevant in alternatives! a major source of vanillin; easily toasted bark bark radial ray Annual ring annual ring pith earlywood sapwood rays latewood 2

3 Now let s take an even closer look at oak The building blocks of oak 1. Cellulose (about 45%) transport of polar molecules o o o C3 heat (toasting) ak is water-loving, naturally swelling & shrinking with the uptake and loss of water (and alcohol) C furfural 3

4 Fast flavour transport is one of the strong points of Alternatives 1X wine side Ring porous oak air side 2.5X air side 2X The building blocks of oak 2. emicellulose (about 22%) acetic acid release this unit is present on C about 7 in every 10 sugar units 3 c the backbone of hemicellulose consists present on about 1 in 10 sugar units of simple sugars - about principally xylose C 3 on toasting these release simple sugars and these in turn caramelise to give sweet associated aromas "markers" include 2 C 5-hydroxymethyl furfural C C furfural 4

5 The building blocks of oak 3. Lignin (about 25%) ak contains many lignins, Some more useful to us than others And some that is wine soluble heat energy G:S ratio in untreated oak lignin = 1:1 G:S ratio in toasted oak lignin = 1:2 1:4 depending mainly upon the toasting process C C Vanillin is the most desirable of all flavourings to emerge from ak during maturation C3 Vanillin from Guaiacyl lignin (G) C 3 C 3 Syringaldehyde from Syringyl lignin (S) The building blocks of oak 3. Lignin (about 25%) "relative" amounts of 0.87 ppm coniferaldehyde increase C as barrel becomes exhausted C The Phenolic aldehydes C C 3 C C C C3 C C C3 coniferaldehyde Vanillin vanillic acid sinapaldehyde C syringaldehyde 0.51 ppm vanillin is the only phenolic aldehyde with a low odour threshold - ca 0.02ppm and a "jnd" ca 0.5 ppm syringic acid C C C 3 C C 3 C3 3 3 C3 0.26ppm 3.53 ppm 5

6 The building blocks of oak 4. Tannins (0.8 10% Vescalagin / Castalagin (56% of total in fresh oak) c c o o changes on seasoning and toasting c o 2 C hexahydroxy diphenic acid 2 C C C Gallic acid D-glucose C Ellagic acid Cellulose. The Influence of ak Wood on Barrel Maturation emicellulose Lignin ak Tannins (after seasoning & heat treatment) no direct effect wood sugars ("body") caramelisation products color increase in blended complexity production of vanilla promotion of oxidation products production of astringency removal of off-notes (e.g. rubbery) 6

7 ur Standard ak Analysis (not wine, that s a little different) F MT F T F MT F T Total tannin (FC method < 8% < 8% 'smoke phenols Tannin & tannin breakdown phenol Gallic Acid guaiacol Vescalagin m/p-cresol Castalagin o-cresol Ellagic acid methyl guaiacol emicellulose caramelisation 4-ethyl phenol MF ethyl guaiacol Methyl furfural ak lactones Furfural trans lactone Lignin degradation compounds cis lactone Vanillic acid Ratio Syringic acid Vanillin Syringaldehyde G:S Coniferaldehyde Sinapaldehyde in milligrams per Kg at 12% MC ur Standard ak Analysis (not wine, that s a little different) F MT F T F MT F T Total tannin (FC method < 8% < 8% 'smoke phenols Tannin & tannin breakdown phenol Gallic Acid guaiacol Vescalagin m/p-cresol Castalagin o-cresol Ellagic acid methyl guaiacol emicellulose caramelisation 4-ethyl phenol MF ethyl guaiacol Methyl furfural ak lactones Furfural trans lactone Lignin degradation compounds cis lactone Vanillic acid Ratio Syringic acid Vanillin Syringaldehyde G:S Coniferaldehyde Sinapaldehyde moderate tannin breakdown extensive tannin breakdown light creamy toastiness the best toastiness marker vanilla & complexity tells us about the amount of heat used to toast 7

8 ur Standard ak Analysis (not wine, that s a little different) F MT F T F MT F T Total tannin (FC method < 8% < 8% 'smoke phenols Tannin & tannin breakdown phenol Gallic Acid guaiacol Vescalagin m/p-cresol Castalagin o-cresol Ellagic acid methyl guaiacol emicellulose caramelisation 4-ethyl phenol MF ethyl guaiacol Methyl furfural ak lactones Furfural trans lactone Lignin degradation compounds cis lactone Vanillic acid Ratio Syringic acid Vanillin Syringaldehyde G:S Coniferaldehyde Sinapaldehyde not smoky (too much heat) the best smokiness marker very undesirable smokiness attractive spicy cloves coconut, sun-tan lotion smell high ratio suggests American oak 8