Yeast and Flavour Production. Tobias Fischborn Lallemand Brewing

Transcription

1 Yeast and Flavour Production Tobias Fischborn Lallemand Brewing

2 Content Flavour production by yeast How to control Flavour Production Non-Traditional Yeast to Brew Beer

3 Contribution To Beer Flavor

4 Contribution to Beer Flavor

5 Fermentation Parameter Original Gravity Yeast Strain Yeast Viability and Vitality Aeration Yeast Nutrition CO 2 Pressure Fermentation Temperature Geometry of fermentation vessel (convection) Extract from Tim Meier Dörnberg: Saccharomyces Brauereihefen; 4. Seminar Hefe und Mikrobiologie, Weihenstephan, 2016

6 Yeast in Fermentation WORT (sugars, amino acids, etc.) More yeast! Yeast autolytic compounds Phenols Sulphur compounds Acids (organic & fatty) Alcohols (ethanol & higher alcohols) Aldehydes & ketones Esters CO 2 Glycerol

7 Yeast in Fermentation WORT (sugars, amino acids, etc.) More yeast! Yeast autolytic compounds Phenols Sulphur compounds Acids (organic & fatty) Alcohols (ethanol & higher alcohols) Aldehydes & ketones Esters CO 2 Glycerol

8 Yeast metabolism How does the yeast do this?

9 Yeast metabolism How does the yeast do this?

10 Ethanol & CO 2 1 Glucose Glucose 6-C Glycolysis Dihydroxy-acetone phosphate (3-C) D-glyceraldehyde 3-phosphate (3-C) D-glyceraldehyde 3-phosphate (3-C) 2 Ethanol Ethanol Acetaldehyde Pyruvate 2 CO 2 CO 2

11 Acetaldehyde 1 Glucose Glucose 6-C Glycolysis Dihydroxy-acetone phosphate (3-C) D-glyceraldehyde 3-phosphate (3-C) D-glyceraldehyde 3-phosphate (3-C) 2 Ethanol Ethanol Acetaldehyde Pyruvate 2 CO 2 CO 2

12 Acetaldehyde Healthy yeast - No CO 2 back-pressure - Over oxygenation + High pitching rate + Very high fermentation temperature -

13 Glycerol 1 Glucose Glucose 6-C Glycerol Glycolysis Stress Dihydroxy-acetone phosphate (3-C) D-glyceraldehyde 3-phosphate (3-C) D-glyceraldehyde 3-phosphate (3-C) 2 Ethanol Ethanol Acetaldehyde Pyruvate 2 CO 2 CO 2

14 Control Glycerol High OG + High temperature +

15 Higher Alcohols Amino keto aldehyde + CO 2 acids acids Higher alcohol Glucose pyruvate acetaldehyde + CO 2 Ethanol

16 Control of Higher Alcohols Good FAN supply - Flocculent yeast - Wort Aeration + Strong fermentation movement + High fermentation temperatures + Application of pressure (-) Yeast strain +-

17 Esters

18 Esters

19 Esters Isoamyl acetate Ethyl Hexanoate Ethyl Butyrate Ethyl Acetate

20 Control of Esters - High original gravity + Increased biomass production - High glucose concentration + Vigorous fermentation (ZKG) - Pressure during fermentation(1-tank) - High Fermentation temperatures + High concentration of unsaturated fatty acids - Wort aeration +- Yeast strain (+-)

21 Control of Esters - Increase glucose concentration in the wort: adding 10g/l of sterile glucose solution to the wort follow a specific mashing process to increase the ratio of glucose to maltose

22 Control of Esters -

23 Control of Esters - Fermentation Vessel

24 Phenols Ferulic Acid Coumaric Acid Cinnamic Acid PDA FDC 4-Vinylphenol (Brettanomyces) 4-Vinylguajacol Vinyl benzene (Styrene) Mathias Hutzler, Maximilian Michel, 4. Seminar Hefe und Mikrobiologie Weihenstephan, 2016

25 Control of 4-Vinylguajacol Mash in at ºC + Malt ratio barley : wheat +- Fermentation vessel + (open fermenters) Use the appropriate yeast strain +-

26 4VG (Barley : Wheat Ratio) Fermentation In general contains wheat ( %) more ferulic acid than barley ( %) Better ferulic acid extraction from barley than from wheat higher Feruloylesterase- and Xylanase activity (Arabinoxylan break down) Wheat contains proteins, that can inhibit xylanases COGHE, S. : Ferulic Acid Release and 4-Vinylguaiacol Formation during Brewing and Fermentation: Indications for Feruloyl Esterase Activity in Saccharomyces cerevisiae, J. Agric. Food Chem. 2004,

27 4VG (Barley : Wheat Ratio) Fermentation with POF+ yeast feruloyl esterases produced by brewer's yeast. feruloyl esterases produced by brewer's yeast. COGHE, S. : Ferulic Acid Release and 4-Vinylguaiacol Formation during Brewing and Fermentation: Indications for Feruloyl Esterase Activity in Saccharomyces cerevisiae, J. Agric. Food Chem. 2004,

28 Organic acids pyruvate Acetyl-CoA CoA oxaloacetate citrate malate isocitrate fumerate α-ketogluterate succinate Succinyl-CoA bitter

29 Control organic acids Healthy yeast - Interruption of TCA cycle + Yeast strain +-

30 Fatty acids Palmitic (16:0) Stearic (18:0) Oleic (18:1) Linoleic (18:2) Caproic (6:0) Caprylic (8:0) Capric (10:0)

31 Fatty acids Fatty acids are bad for foam Short chain fatty acids (C8-C14)

32 Control fatty acids Increase yeast growth + Wort oxygenation + High lipid content in wort + High temperature + High pitching rate (+) Yeast health Autolysis +

33 Sulphour Production Intermediates in amino acid metabolism When yeast needs to make sulfur containing amino acids H 2 S (Hydrogen Sulphide) SO 2 (Sulphur dioxide)

34 Control of SO 2 High oxygen - High OG + High lipid concentration - Poor yeast health + Pantothenic acid - Yeast strain +-

35 Control of H 2 S Vigorous fermentation (CO 2 ) - Poor yeast health + Pantothenic acid - Addition of Serine - Yeast strain +-

36 VDK: Diacetyl & 2,3 Pentanedione Produced by yeast during fermentation

37 Amino acid uptake by brewing yeast GROUP A (fast) Glu, Asp, Asn, Gln, Ser, Thre, Lys, Arg GROUP B (intermediate) Val, Met, Leu, Isoleu, His GROUP C (slow) Gly, Phe, Tyr, Try, GROUP D (little or no) Pro Ala, NH 3

38 Valine, Leucine & Isoleucine Synthesis

39 Diacetyl Production & Reduction

40 Control of Diacetyl 1. Limit the amount of precursor (alpha-acetolactate) Lower temperatures Good yeast growth (healthy yeast) Adequate aeration 2. Accelerate the conversion of precursor to diacetyl Diacetyl rest at elevated temperatures Good yeast growth (healthy yeast) Lower end of fermentation ph (< ph 4.5) 3. Use of nutrients

41 Non Saccharomyces strains Torulaspora delbrueckii reduce volatile acidity in high-sugar fermentations complexity and floral/fruity aroma

42 Non Saccharomyces strains Candida zemplinina Osmotolerant Reduces acetic acid, increases glycerol Saccharomycodes ludwigii Non alcoholic beers Only use glucose

43 Non Saccharomyces strains Pichia kluyveri Non alcoholic beers Hanseniaspora uvarum Low alcohol tolerance ethyl acetate Brettanomyces

44 Hybrids

45 Yeast Hybrids Greater fermentation efficiency Fermentation speed Thermal tolerance Ethanol tolerance Greater diversity in sensory expression Flavor Aroma

46 Questions Tobias Fischborn