Related Clues:

• 4-H Club concern
• Upper crust?
• Vegan's gelatin substitute
• Petri-dish substance
• Farmer's earth
• Stuff in a petri dish
• Bedrock's covering, perhaps
• Bed for bacteria
• It helps a culture advance
• Make grimy
• Frosting thickener
• It helps a culture grow
• Jelling agent
• Gelatin in a petri dish
• Microbiologist's gel