1. Microbes I have
known and loved.
Chris Heathcote
@antimega
Mixed Grill 2011
I’m going to talk about microbes, yeasts and bacteria. There are going to be a lot of long
words that I can’t pronounce, as I’m not a scientist, I just play one on TV.

2. Kills 99.9% of germs dead.
Most of the time we want to kill micro-organisms (and quite rightly, as a few of them really
disagree with humans). Like this cold virus I’ve got.

3. UV cutting board cleaner?

4. Germs are tasty.
An awful lot of germs are really really tasty. Well, what they make is tasty. They’re really good
at taking one substance and turning it into others. It’s the closest we’ve got to alchemy. Let’s
take a quick tour of the fungi and bacteria that make things we eat.

5. Yeast.
Would humanity have survived without yeast? Yeast turns sugar and water into alcohol and
carbon dioxide, which kills off a lot of more harmful bacteria. Brilliant.
It was first proved in 1836 that this process wasn’t chemical and needed living cells.

6. Brewer’s yeast.
Baker’s yeast.
You may have heard of brewer’s yeast and baker’s yeast.

7. Brewer’s yeast.
Baker’s yeast.
Saccharomyces cerevisiae.
Well, they’re the same thing: saccharomyces cerevisiae.

8. Ale yeast &
lager yeast.
Saccharomyces cerevisiae &
Saccharomyces carlsbergensis.
But there are different yeasts for ale and lager.

9. Ale yeast &
lager yeast.
Saccharomyces cerevisiae &
Saccharomyces carlsbergensis
Saccharomyces pastorianus.
I feel sorry for Carlsberg. They set up the first laboratory to explore how to make better beer,
and didn’t patent any inventions, and they go and rename the first lager yeast strain
identified and cultured.

10. Ale yeast &
lager yeast.
Top cropping &
bottom cropping.
More easily, ale yeast ferments at the top of the barrel, lager yeast at the bottom.

11. But these have been bred to produce different flavour characteristics - these are from a yeast
catalogue - ‘moderate esters’, apple, bubblegum, hint of nut, light citrus character.
They’re also bred to be quick - about 5-10 days for primary fermentation, plus they can cope
with higher temperatures, higher alcohol concentration, clump together and clear from the
beer quicker (flocculation), and eat more of the sugars in the wort (attentuation).

12. This is a beer flavour wheel. Beer has a far wider set of potential tastes than wine, due to the
different raw ingredients and many kinds of yeasts used.

13. Moulds.
Penicillium camemberti,
Penicillium roqueforti,
Penicillium nalgiovense.
Some other fungi. It’s been found that eating mould-ripened cheese can slow the growth of
strep that cause tooth decay.
Nalgiovense is used on the surface of salami to protect from other fungi and bacteria (and
improves the taste) - the bacteria inside charcuterie and cured meats is a lactobacteria. In
about 1950 it was determined that exposing ham to bacteria made them taste better than just
brining.

14. Botrytis cinerea &
Ustilago maydis.
A call out for two odd fungi - both cause infections actually on the plant before picking or
harvesting.
Noble rot / winemaker’s lung
Corn smut / huitlacoche

15. Bacteria.
Let’s also look at some bacteria.

16. Lactobacteria.
Lactobacillus sanfranciscensis,
Lactobacillus casei,
Lactobacillus brevis,
Lactobacillus delbrueckii,
Lactobacillus kimchii.
take sugars and turns them into lactic acid:
sanfranciscensis produces sourdough,
casei produces probiotics, also found in Cheddar and green olives,
brevis produces sauerkraut and pickles (often with Leuconostoc and Pediococcus),
delbrueckii with strep salivarius is used for most commercial yoghurt,
the last needs no explanation.

17. Natto.
Bacillus subtilis natto.
Subtilis is naturally occurring in grass and hay - they found one strain that didn’t need the
beans to be packed in hay to ferment. One oddity of subtilis is that it forms long-chain
polysaccharides, which are the strings in natto.

18. Cacao.
Saccharomyces rosei,
Hansenula anomala,
Pichia fermentans,
Pichia membranaefaciens,
Trichosporon cutaneum...
Most people don’t realise chocolate is a fermented product.
Cacao has to be fermented to get the chocolate flavour -
2-7 days of fermentation of the seeds and pulp.

19. Swiss cheese.
Propionibacterium freudenreichii &
Lactobacillus helveticus.
Lacto Helveticus makes the amino acids needed for P. freudenreichii, which ferments lactate
to form acetate, propionate and carbon dioxide.
So those are some of the simple bacteria and fungi that ferment foods, but I want to talk
about something more complex.

20. SCOBYs.
SCOBYs are my favourite thing at the moment.

21. Symbiotic
Colonies
Of
Bacteria &
Yeast.
SCOBYs are a rich ecosystem of bugs, often helping each other or fighting between
themselves, and a side effect is making truly complex flavours.

22. Kombucha.
Kombucha is one of the best known - makes a tea-like drink.

23. This is the mother or SCOBY. Liquid SCOBYs often make a raft out of cellulose to cling on to.

24. It’s a hard enough, flexible material that when dried can even be made into clothes (this is
from a research project at the RCA).

25. Mother of vinegar.
Mycoderma aceti.
This is how vinegar is made too. Bacteria turn alcohol into acetic acid.

26. Ginger beer plant, ke r,
tibicos, sourdough.
There are several other scobys that are drinks, but also sourdough is a SCOBY - yeast, lacto
and acetobacters.

27. Cheese.
Hand-crafted, artisan cheeses are really complex ecosystems.
No-one knows completely how it works - a lot of work in the last 10 years to try to
understand what’s going on.
Starter bacteria, which determine the final flavour, have been found to disappear very quickly.
Even different parts of the cheese have different strains.
Different strains have been found in summer and winter.
Every truckle of cheese has the potential to be different.
Most yeast and bacteria come from the environment where they mature.
This can be a problem - for example one of the major Somerset craft cheesemakers (Keen’s I
think) built a larger dairy, but proved to be too clean, and for 6 months couldn’t make good
cheese. Often it’s a long-used wooden spoon (replaced by plastic without thinking) or the
need for food preparation cleanliness that can spoil production overnight.

28. Lambics.
So to come full circle, my favourite beer. Lambics are beers fermented with wild yeasts from
around Brussels.

29. This is the wort cooling tank at the Cantillon brewery - maybe my favourite place in the world
(it’s right in the centre of Brussels and they love visitors).
Three important things - the tank is open to the environment (as compared to most beer
production where it’s all about keeping equipment sterile), the roof is open to the outside,
and here, where they’ve had to build a new roof, they actually kept the old roof tiles and
placed them underneath the new roof - as they believed a lot of the needed bacteria and
fungi have stored themselves there. Where the beer matures in casks is positively dingy and
cobwebby. There’s even a brewery cat that has a run of the place.
Also brewing only happens in the cooler months, to help the right mix of microbes grow in
the right order and one not to dominate.
(there’s a public brewing day on 6th March)

30. Lambics.
Brettanomyces bruxellensis,
Brettanomyces lambicus,
Lactobacillus,
Pediococcus...
All traditionally beer spoiling organisms, considered defects (brett - barnyard, wet animal,
burnt plastic).
Brett bruxellensis and the yeasts that produce the particular flavour only naturally occur
around Brussels. Most wild yeasts produce horrible tasting beer.
These also take a lot longer than commercial yeast to ferment (over 8 months instead of 5
days), and often a few years of maturing to settle down into something drinkable.
Quite hard to find (beermerchants online and utobeer and the Rake in Borough Market are
good places to start), but do try it, it’ll change your view of what beer can taste like forever.

31. Other things made by
microbes.
Glutamates, vitamins, gellan, nata de coco,
miso, pu-erh tea, washed co ee, calpis,
skyr, garri, garum, sh sauce, soy sauce,
tempeh, injera, appam, idli, surströmming...
This is just scratching the surface, and I think pretty much every tasty meal includes one
product of fungi or bacteria, so be thankful these evolved alongside us.

32. Thank you.
@antimega
anti-mega.com