Analysing the shipwreck beer

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Researchers in Finland have discovered live bacterial species in antique beer originating from the mid-1800´s. The discovery has interesting potential for food and health applications, according to VTT Technical Research Centre of Finland.

A few bottles of beer were found in an old shipwreck in the archipelago of Åland in Finland during the summer of 2010. Researchers have now managed to isolate four different species of live lactic acid bacteria from the beer.

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Analysing the shipwreck beer

  1. 1. Analysing the shipwreck beer Annika Wilhelmson, John Londesborough and Riikka Juvonen VTT Technical Research Centre of Finland Press conference 10th May 2012
  2. 2. 209/05/2012 The aim of the research was to  find out what kind of yeast (and possibly other microbes) were used to make the beer  isolate and cultivate any living yeast cells and other microbes from the beer  find out what the raw materials of the beer could have been  find out what sort of beer people were drinking in those days
  3. 3. 309/05/2012 The research scientists have  opened the bottle with extreme care in an aseptic environment to prevent breakage and contamination  tasted the beer (1st bottle)  analysed the chemical composition of the beer  cultivated living microbes  isolated and analysed DNA in order to identify yeasts or other microbes in the beer
  4. 4. 409/05/2012 The liquid was identified as beer because of the presence of  Hops  Malt sugars  Aromatic compounds and amino acids typical of beer
  5. 5. 509/05/2012 An abundance of microbial cells was visible  No live yeast was found  Live bacteria were found
  6. 6. 609/05/2012 Both beers were a bright pale gold  The colour is typical for a modern lager or ale  Too pale for a porter
  7. 7. 709/05/2012 The hop residues show these are beers  Two different beers, with much more hops in bottle C49  The wort was boiled after adding hops, so converting α-acids into iso-α-acids  Large amount of β-acids shows hops were an old (19th century) variety Data of Prof. Dr. Thomas Hofmann, TU Munich.
  8. 8. 809/05/2012 The amino acids and peptides were typical of beer  High proportion of free proline and total glutamine  differs from cider, wine  Low protein content: only 5-7 mg/l compared to 200-500 mg/l in modern, filtered lager beer
  9. 9. 909/05/2012 Sea salt in the beers  High sodium levels  Potassium levels are normal
  10. 10. 1009/05/2012 . . and other changes happened  Alcohol now 2.5 % ABV. Some alcohol escaped into the sea or was used by bacteria  Low pH: bacteria have made acids  Lots of glucose but little maltose and maltotriose: enzymes active after most microorganisms died
  11. 11. 1109/05/2012 Yeast-derived aroma profiles resemble reference beers But: High 2PE and 2PEA => rose aroma in fresh beer?  High EHex => apple aroma?  Low 3MBE (banana aroma) might be due to chemical instability
  12. 12. 1209/05/2012 What the bacteria did over the years  Huge amounts of organic acids. Bacteria found in the bottles can make them  They cause the sour, vinegary flavours noted by the taste panel, and hide the pleasant aromas
  13. 13. 1309/05/2012 Phenolic compounds  High levels of phenolics give smoky, bitter, clove-like aromas  Low in most modern lagers but high, for example, in wheat beers
  14. 14. 1409/05/2012 A result of old technology?  High furfural might result from mashing over an open fire  Furfural tastes ”aromatic, almond-like” or ”burnt, bready”  Was it a mistake, or was that taste appreciated?
  15. 15. 1509/05/2012 Dead yeast cells were discovered in both beers  These cells could be brewer's yeast cells under great stress or some other yeast species, e.g. Dekkera  Dekkera yeasts are an important component of certain lambic beers. 1509/05/2012
  16. 16. 1609/05/2012 Traces of yeast DNA were detected in one of the bottles  Most yeast DNA from dead cells degraded over the years  Only traces of yeast DNA were detected  The yeast was closely related to Cyberlindnera jadinii  Its role in brewing remains unclear
  17. 17. 1709/05/2012 Remarkably stable bacteria were still alive in the beers  The longest surviving bacteria yet found in beer  Lactic acid bacteria ferment sugars mainly to lactic acid  Often grew alongside yeast in beer fermentations  The two bottles had different composition of live bacteria  produced at different places or times or with different raw materials
  18. 18. 1809/05/2012 Four different species of lactic acid bacteria were revived  Pediococcus damnosus  Lactobacillus malefermentans  “Lactobacillus backii”  Highly adapted to beer brewing  Rarely or never found in other habitats  Still today found in breweries  Lactobacillus kisonensis  Discovered in 2009 from a traditional fermented turnip product (sunki) 1809/05/2012
  19. 19. 1909/05/2012 The role of these bacteria in the beer production remains unclear  In the early 19th century, beer fermentation used an unknown mixture of brewhouse microbiota  Bacteria may have contributed positively to the taste when the beer was fresh  May have been harmless contaminants  Over the long years they caused excessive souring 1909/05/2012
  20. 20. 2009/05/2012 The properties of the bacteria suggest adaption to brewery environment  Able to grow in up to 4-8%v/v ethanol  No growth below pH 4-5  Some could grow at low temperatures (4-10°C) and thus even under the sea  Low hop tolerance compared to modern beer spoilage bacteria  Some produced viscous sugar polymers (beta-glucan) which can protect cells against hostile conditions
  21. 21. 2109/05/2012 The same species can be beneficial or detrimental depending on the food process and product  Lactic acid bacteria are generally regarded as beneficial organisms safe to man  Long history of use in the production of many fermented beverages and foods  e.g. lambic beer, kvass and sourdough bread, kefir, yoghurt  Some are used as probiotic cultures  But causes spoilage of some products  e.g. mayonnaise, soft drinks 2109/05/2012
  22. 22. 2209/05/2012 The live bacteria have many potential applications  Stress tolerant and potentially very stable in food and non-food applications  Functional starter cultures for modifying the structure, taste, healthiness, shelf-life and safety of foods and beverages  They produce sugar polymers that could be used as food texturizers, fat substitutes, fibre sources and prebiotic compounds  Interesting models to improve our understanding of long-term survival of non-spore-forming bacteria 2209/05/2012
  23. 23. 2309/05/2012 VTT - 70 years of technology for business and society

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