Do Now

Why is it important to keep accurate records when harvesting? What types of records should you be keeping?

1

Harvesting Lettuce and Recordkeeping

Unit 1

Lesson 4

Day 1

Lettuce Harvesting Video

https://youtu.be/Azb4Wf3YJ-E

Harvesting Tips

General Tips

• Harvest lettuce in the morning
• Harvest before it bolts
• stem stretches upwards and begins making flowers and seeds

Harvesting to Continue Production

• Cut leaves periodically
• Take the outer leaves first
• Harvest leaves from multiple plants

Harvesting Whole Lettuce Plant

• Cut the entire head of lettuce at the base

Tools Needed to Harvest

• Scissors, Pruning Shears, or Harvesting Knife
• Gloves (optional)

*make sure hands and tools are clean before harvesting

Harvest Photos

Weighing Plants

https://community.marsfarm.com/t/mv1-summer-trials/67/19?u=peter

Directions to Harvest from MV1

1. Wash hands and harvesting tools before beginning
2. Open up the MV1 panel
3. Grab a pot from the reservoir tray
4. Use scissors (or other cutting tool) to cut at the base of the lettuce
1. Cut individual leaves/sections of leaves or cut the entire head of lettuce
2. Watch your fingers
5. Place leaves to the side
6. Grab additional pots and repeat as desired
7. Weigh harvested lettuce leaves to get final harvest weight and record it in your notebooks
• Copy the tables below into your notebooks to record data

Do Now

Why is food safety important?

​

How do you think the lettuce you grew will taste?

9

Food Safety and Processing

Unit 1

Lesson 4

Day 2

Microorganisms of Concern in Fresh Produce

​

• Parasites - protozoa or intestinal worms that can only multiply in a host animal or human
• Ex: Giardia lamblia, Cryptosporidium parvum, Cyclospora cayetanensis, Toxoplasma gondii
• Commonly transmitted by water

Challenges with Fresh Produce

• Viruses - small particles that multiply only in a host, not in the environment or on produce
• Ex: Norovirus, Hepatitis A
• Contamination most often linked to ill workers handling produce or from contaminated water
• Some produce eaten raw
• Microbial contamination is hard to remove once present
• Natural openings, scratches, bruises on produce
• Rough surfaces or ridges on produce
• Contamination is sporadic
• Bacteria multiply quickly given right conditions

How Contamination is Spread

• Humans
• Improper health & hygiene
• Illness or injury
• Animals
• Fecal contamination, manure runoff, etc.
• Animals feeding in fields
• Contaminate water sources
• Water
• Irrigation water
• Washing
• Floods
• Runoff

​

• Soil Amendments
• Application too close to harvest
• Improper/incomplete treatment
• Runoff
• Wind spread
• Surfaces, Equipment, Tools, Buildings
• Unclean surfaces
• Overgrown areas
• Standing water
• Lack of cleaning schedules
• Lack of proper cleaning and sanitation

Cleaning vs Sanitizing

• Cleaning - physical removal of dirt from surfaces which can include the use of clean water and detergent

​

• Sanitizing - Treatment of a cleaned surface to reduce or eliminate microorganisms

​

You cannot sanitize a dirty surface! Cleaning always comes first!

How to Clean & Sanitize Food Contact Surfaces

1. Remove any dirt and debris from surface area

​

• Apply an appropriate detergent and scrub the surface

​

• Rinse the surface with clean water to remove all soap and debris

​

• Apply a sanitizer approved for use on food contact surfaces. Let air dry.

Preventing Contamination & Keeping Things Clean

• Consider everything that touches or impacts produce
• Packing and picking containers
• Packing equipment
• Hands and clothing
• Postharvest water
• Buildings (i.e., coolers, storage areas)
• Transport vehicles

Think about the flow of work in the garden, field, greenhouse, classroom, etc.

Think about what areas and tools need to be cleaned and how often.

• Use basic housekeeping to keep things clean
• Train employees
• Eliminate pests & debris
• Minimize standing water
• Keep facilities & tools organized
• Follow Standard Operating Procedures (SOPs)
• Complete regular inspections of facilities & tools
• Make a Food Safety Plan
• Keep accurate records

Reminders: Before Cleaning the Lettuce

1. Tie back long hair and/or wear hair nets or beard nets
2. Clean and Sanitize surface areas
3. Clean all tools and equipment needed for washing and processing lettuce
4. Wash your hands before cleaning and processing lettuce

Cleaning Lettuce

Wash your hands BEFORE you clean the lettuce

1. Prepare a bowl of clean cold water
1. Vinegar can be added to water if desired to promote crisp, fresh leaves
2. Remove any damaged leaves or undesirable parts of the lettuce
3. Rinse leaves in running water and/or put leaves in bowl of water
4. Move/swish leaves around in water bowl with your hands to clean leaves
5. Let lettuce soak in the water for a couple of minutes
6. Remove leaves from water bowl and remove excess water from lettuce
• A salad spinner can be used to dry the leaves or simply shake leaves thoroughly

Processing Lettuce

Make sure your hands are CLEAN and/or wear gloves!

1. Grab a chopping board and knife
1. A knife glove may be used on opposite hand to prevent cutting fingers
2. Place lettuce on chopping board and chop it to desired thickness for salad
3. Place cut lettuce in a clean bowl for serving
4. Add toppings and dressing to lettuce as desired and enjoy!

Do Now

How do you think the OutRedgeous Lettuce Project went overall?

​

Are there any ways that you could have improved?

​

Are there any ways the project could have been improved?

​

How did the lettuce taste?

​

Do you have any other thoughts on the project?

21

Class Discussion & Cleaning the MV1

Unit 1

Lesson 4

Day 3

Cleaning and Disinfecting the MV1 Unit

1. Remove the pots and dump out the remaining plants and soil outside or in compost
1. If the posts are broken, cracked, or cannot be reused, throw them away
2. Spray out the pots with a hose and wash them in the sink
• Let them air dry on a clean surface, drying rack, or on clean towels
3. Take out the tray and reservoir, dump out the water, and wash them in the sink
• Let them air dry on a clean surface, drying rack, or on clean towels
4. Wipe down the inside of the MV1 panels
• Towels/sponge should be damp, not soaked
• Let it air dry
5. Wipe down the outside of the MV1 panels
• Towels/sponge should be damp, not soaked
• Let it air dry
6. Wipe down the top of the MV1 with a DRY towel
• Clean vents of fans and around sensors
7. Unplug the unit if it is not being used again in the near future

Use Simple Green, Bleach, or another disinfectant product to destroy bacteria on the pots and other surfaces during cleaning.