Beer, Wine, Yoghurt and Cheese Making

To get different flavours change:

• type of grapes
• type of yeast
• temperature
• maturation (storage) time

fruit is crushed -> gets juice + sugars out of it

not always necessary to add yeast -> there's natural yeast in fruit -> yeast is needed as an energy source

during fermentation anaerobic respiration happens to make carbon dioxide and ethanol

After fermentation the wine is cleared, stabilised and matured

Main ingredients of beer are:

• barley -> allowed to germinate -> starch in it broken down by enzymes in germinating grains -> malting
• water -> mixes with crushed grains -> makes sugary solution
• hops -> give beer flavour
• yeast -> sugary solution is extracted + fermented -> turns sugar into alcohol

By-products are: animal feed, fertiliser and food products

Beer is pasturised before sold to kill microbes

starts with lacto bacillus bacteria

milk boiled to sterilised it -> gets rid of unwanted bacteria

bacteria grows + ferments

lactose (milk sugar) fermented producing lactic acid

lactic acid -> makes milk protein clot + solidify into yoghurt

fermentation carried out best in warm milk -> increases the rate of reaction

solid = curds

discarded liquid = whey

microbes in milk make lactic acid

milk protein turns into solids called curds

milk protein is preserved as cheese

curds get more acidic which encourages solidification

curds are separated from the liquid by filtration

curd is made into hard cheese by filtering it -> adding salt-> pressing it -> leaving it to ripen

both grown in large vessels called fermenters

used when large amounts of the organism are needed

industrial fermenters usually have:

• air supply - aerobic respiration
• stirrer - keeps the micro-organism in suspension - mixedwith other fermenter materials - mantains temperature too!
• water-cooler jackets - remove heat from the respiring microbes
• instruments to monitorpH +temp.

mycoprotein - fungus - fusarium - protein rich +suitable 4 veggies

penicillin - mould - penicillium - used for preventing infections by making chemicals that kill bacteria by disrupting the cell walls

penicillium only make penicillin after using up most of the nutrients in the fermenter for growth