Plants and People -- Beer-making

Important:  Download and read the pdf of the detailed brewing procedure and the one on racking and bottling.  The powerpoint for this lab is here.  

INTRODUCTION

Beer has a history going back some 11,000 years.  Beer-making involves converting the starches in grains into sugars and fermenting these sugars into alcohol.  We will brew several varieties of beer using the top-fermenting method that produces beverages known as ales.

Objectives for this part of the lab are to:
□ learn the components used in making beer
□ outline the steps in the brewing process
□ learn about the various types of beer
□ study the plants used to make beer

Safety concerns:
□ Brewing is wet and messy.  Wipe up any water that spills on the floor.
□ Use caution with the hotplate and breakable glass equipment
□ The hotplate is electric; we are using lots of water.  Be careful mixing the two.

MATERIALS NEEDED

beer kit with grains and hops                            scale
large pots                                                        hotplate
thermometer                                                   iodine starch test kit
strainer                                                           ice
cheesecloth                                                      fermenters (large glass jugs)      
hydrometer                                                     air lock
racking tools                                                    bottles and caps
bottlecapper                                                   

THE BREWING PROCESS

--This is a general outline.  Follow the directions in the recipe you will be given in lab.

MASHING turns the starches in grains into sugars.  The usual starch source is malted (sprouted) barley.  Enzymes present in the grains themselves will do much of the work for us.

    1.  Heat 3 quarts of water to 165° Fahrenheit in the brew pot.
    2.  Weigh out grains according to your recipe.
    3.  Add grains to water all at once and stir to wet thoroughly.
    4.  Temperature should be about 152° +/2°F. If not, adjust by adding heat or ice.
    5.  Check for presence of starch by the iodine test.
    6.  Maintain heat at 152°F for 60 minutes so amylases can break down starch to glucose and dextrins.  This is called saccharinization or saccharification.
    7.  Check for absence of starch by the iodine test.
    8.  Raise temperature to 170° F to “kill” enzymes.
    9.  Pour the mash through cheesecloth and strainer into another pot.  The sweet liquid, the part we want to keep, is now called wort.


SPARGING is rinsing the grains to obtain all of the sugars

    10.  Sparge the grains with 2 quarts of 170°F water to collect a total about 1.25 gallons of wort.

BOILING concentrates the sugars and extracts flavors from hops, which are now added.

    11. Boil the wort for 60 minutes, adding hops at the proper times and amounts according to your recipe.

FERMENTING will convert the sugars into alcohol.
    14.  While the wort is boiling, clean the brew pot and sterilize your fermenter.
    15.  Strain the boiled wort into the cleaned brew pot and chill on ice to 60°.
    16.  When the wort has reached 60°F, take a hydrometer reading and write down the original specific gravity.  There is a formula for converting specific gravity to % sugar, which gives an indication of final alcohol concentration.
    17.  Pour the wort into the fermenter, add the yeast, and add the air lock.
    18.  Let the fermenter sit for 1 to 2 weeks.
    
RACKING AND BOTTLING

    19.  Rack the beer off the sediment and transfer the beer to the bottles.
    20.  Cap the bottles.
    21.  Let the beer age in the bottles and then chill.
    22.  Examine the results (responsibly!)

                
RECORD:

Style and characteristics of the beer you made:

Scientific names of plants used in the beer you made:

Scientific name of the hops you used:

Scientific name and particular strain of the yeast you used:

Starting hydrometer reading:

Final hydrometer reading:

Percent alcohol by volume:

And how did it turn out?

QUESTIONS FOR THOUGHT, REVIEW, AND STUDY:

1.  Beer is often called “liquid bread.”   What similarities does beer share with bread, in terms of components and production methods?   What is one component of bread that is absent in beer?

2.   Where do the enzymes that break down the proteiens and starches in the grains into sugars come from?

3.    Name the basic steps in the beer-making process.

4.    Define the terms wort, sparge, and saccharification.

5.    What does a hydrometer measure?  What can be determined with this measurement?  What can be calculated or predicted from the measurement?

6.   Why are the grains and water heated to 170°F during mashing?

7.  Where did fermentation occur in our beers?  Did we make ales or lagers?  What’s the difference?

8.   What is racking, and why did we want to do it?

9.   What could you do to a beer if you wanted it fizzier or wanted to give it a higher alcohol content?

10.  What part of the hops plant is used?  Are hops absolutely required for beer-making?

11.  How is beer-making similar to wine-making?  How is it different?



Last updated 1-18-2012  MDR