Brewing Beer

For fun and (very little) profit

Created by Laurence J MacGuire a.k.a. 刘建明 a.k.a Liu Jian Ming

ThoughtWorks Xi’An, 2016/11/16

History

• Mesopotamia (current Iraq) ~5000 BC
• Egypt ~3000 BC (Pharaohs and slaves!)

History

• Main drink in Europe (where grapes don’t grow)
• Started using hops ~800 AD (improved shelf-life)
• Larger scale brewing, and exports in ~1200 AD

History

• Had been female dominated until now
• ~1700 Scientific process: Thermometer & Hydrometer
• Industrial revolution = Industrial brewing
• US Prohibition led bootleggers to water down beer

History

• Probably why American beers suck (“light” beers)
• Recent surge of interest in brewing
• Microbreweries everywhere
• Even Xi’An
• ThoughtWorks office

Beer Contents

• Water
• Alcohol
• CO₂
• Sugars + Starches
• Acids + Other stuffs

Ingredients

• Water
• Cereal/Grain
• Hops
• Yeast

Grains (谷子)

• Barley (大麦)
• Wheat (小麦)
• Buckwheat (荞麦)
• Rye (黑麦)

Barley

Wheat

Buckwheat

Rye

Hops (啤酒花)

• Cascade
• Mosaic
• Centenial
• Simcoe
• etc, etc

Hops

Added for flavour, but also acts as a natural preservative.

Close relative to the cannabis plant.

Hops

Hops

Cannabis

Cannabis

Yeasts (酵母)

Saccharomyces Pastorianus (Carlsbergensis)

Saccharomyces Cerevisiae

Brettanomyces Bruxellensis

And others. They are originally from the wild (air).

What’s Happening?

Hydrolysis + Alcoholic Fermentation

C₆H₁₂O₆ → 2x ( C₂H₅OH ) + 2x ( CO₂ )

水解 + 发酵

The Process

• Malting
• Mash
• Sparge
• Boil
• Ferment
• Rack

Malting

• Dry the grain out
• Make it wet again (so it germinates)
• Roast it (to dry it again, and stop germination)

Also produces the ‘amylaze’ enzyme, which catalyses the Starch to Sugar hydrolysis.

淀粉 / 生化 / 水解

Malting

Malting

Malting

Two factors: Guess what.

Malting

Milling (碾磨)

Milling

Milling

Mashing

Mashing

• Let the grain rest in hot water for some time
• Transforms starches in to various sugars (hydrolysis)
• “Amylaze” was a catalyst
• Disolve a lot of sugar into the “wort”

触媒

Mashing

Two factors: Guess what.

Controlled Mash

Controlled Mash

Controlled Mash

Sparging

Sparging

Sparging

• Extract more/remaining sugar from the grain
• Into “clean” water (to be added to the wort)

Uses the diffusion principle (high vs low concentrations)

Result:

Wort

Sweet brown water, basically.

Mashing duration and temperatures affect which types of sugars are extracted.

Eg, (Malto)dextrose vs (Malto)dextrin

(葡萄糖 vs 糊精)

Measurement

Hydrometer

Relative volumetric mass of the wort vs “clean” water.

The difference is assumed to be sugar.

Reading called “gravity”

比重计

KPI

Efficiency

What % of the sugar did we extract?

Boil

Boil

• Boiling the wort for ~1 hour.
• Add hops at various timings.

Boil

• Reduces water volume (affects sugar content)
• Extracts the hops’ oils and acids
• Sterelise

Boil

Few Factors: Guess what.

Boil: hops

Measurement

Take another “gravity” reading (after having cooled the wort)

(called “original gravity”)

Ferment

Ferment

Ferment

Ferment

Factors

Ferment: Wort

• Which sugars were extracted?
• How much of each

Different sugars may ferment differently (or not at all).

(*-ose vs *-in)

Ferment: Yeast

• Ferment different sugars
• Have different temperature ranges

Ferment: Yeast

Easy to control. You buy it.

Just be super super clean (no contamination).

Ferment: Temperature

• Affect how fast it goes
• Affects other flavours as well

Ferment: Temperature

Ferment: Temperature

Ferment

Post-Ferment

Gravity Reading

so we can derive the alcohol percentage.

KPI: fermentability (how much sugar did we transform?)

Beer Types

Mill

Mash Tun

Mash Tun Hose

Mash Tun Hose

Mash Bag

T Pipe

Clamp

Hose to Clamp

Hose to Clamp

Hose

Clamp Assembly

Boiler

Bubbler

Beaker

Hydrometer

Keg

Sampling Tube

sanitiser

Pouring Bot

Pouring Bot

Pouring Bot

Pouring Bot

Pouring Bot