Updated Nov 19, 2019


Part of University of California, Davis

A simple and low-cost tool for checking food dryness to prevent mold growth and the production of mycotoxins (such as aflatoxin) after harvest.


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Stage 5: Scaling

The Horticulture Innovation Lab at the University of California, Davis is partnering with in-country businesses and entrepreneurs to establish DryCard manufacturing, marketing, and sales. DryCard is currently available for purchase in 10 countries.

Focus Areas:

Food Safety and Standards, Post Harvest and Public-Private Partnerships

Food Safety and Standards, Post Harvest and Public-Private PartnershipsSEE LESS

Implemented In:

Tanzania, Rwanda, Guineaand 7 MoreSEE ALL

Tanzania, Rwanda, Guinea, Thailand, Guatemala, Mexico, Ghana, Uganda, Sierra Leone and NepalSEE LESS

Countries Implemented In
Funds Raised to Date
Verified Funding


Drying is a technique used to preserve harvested products, but knowing when products are dry enough can be difficult. When products are not dried below 65% equilibrium relative humidity, they can grow mold and produce harmful mycotoxins such as aflatoxin. Common methods to test for dryness such as biting, touching, or sniffing the product are unreliable and inaccurate. Electronic devices that measure moisture or humidity are often too expensive and difficult to use.



The DryCard is a low-cost and simple tool that measures food dryness by changing colors to reflect the equilibrium relative humidity of a product. This technology allows users to ensure that their product is dry enough to prevent mold growth and mycotoxin production.

Target Beneficiaries

Smallholder farmers, traders, and aggregators

Mission and Vision

To reduce postharvest losses and increase the food safety of dried products.

Innovation Description

The DryCard combines a strip of humidity indicator paper with a color scale to indicate the level of humidity, and instructions printed on the card for how to use. To use the DryCard, simply store the card in a sealed plastic bag or glass jar with your product, wait 30 to 60 minutes, and then look at the color of the humidity indicator strip. If the card is blue, this means your product is properly dried and safe to store. If the card is pink, this means your product is still wet and may grow mold and produce toxins.

Competitive Advantage

DryCard is low-cost and can be made from locally available equipment and materials. DryCards are reusable for up to 3 years and can test any kind of dried product. DryCard has instructions printed directly on the card for how to use which can be translated into different languages or pictures. It does not require electricity, batteries, or regular calibration.


Apr 2019
New Country Implemented In
Feb 2019
New Country Implemented In
Sierra Leone
Aug 2018
New Country Implemented In
May 2017
New Country Implemented In
Aug 2016
Date Unknown
Funds RaisedVERIFIED
TITLEReducing postharvest losses in Rwanda
Food Safety and Standards and Post Harvest
Implemented InGuinea, Guatemala, Ghanamore and 9SEE MOREGuinea, Guatemala, Ghana, Cambodia, Burkina Faso, Bangladesh, Rwanda, Mexico, Kenya, Honduras, Zambia, ThailandSEE LESS

Supporting Materials