Can you eat cornstarch blocks?

Cornstarch blocks, also known as oobleck, are a popular science experiment and sensory play activity. They have a solid yet liquid-like texture and are made by mixing cornstarch with water. But can you actually eat cornstarch blocks? Let’s take a closer look.

Are cornstarch blocks edible?

Yes, cornstarch blocks made from standard cornstarch and water are completely edible and safe to eat. Both cornstarch and water are food-grade ingredients that are commonly used in cooking and baking.

Cornstarch is a fine powder made from corn kernels. It is used as a thickening agent in sauces, gravies, puddings, and more. Water simply hydrates the cornstarch particles to create the unique properties of oobleck.

So while cornstarch blocks may not taste great on their own, they are non-toxic and ingesting small amounts is not harmful. Supervision is still recommended for small children as a choking hazard due to the texture.

Nutritional value

Cornstarch itself is a refined carbohydrate with little nutritional value. Here is the basic nutritional profile per 100g of cornstarch (source: USDA):

Calories Protein Fat Carbs
376 kcal 0.1g 0.1g 94.0g

As you can see, cornstarch is almost entirely carbohydrates. It has trace amounts of protein and fat.

The water adds no nutritional value either. So cornstarch blocks made from just these two ingredients contain calories and carbs but minimal complete nutrition.

However, you can boost the nutrition by mixing in peanut butter, chocolate sauce, or fruit purees to make enhanced cornstarch blocks that are more of a treat.

Taste and texture

On their own, plain cornstarch blocks are relatively tasteless. Cornstarch has a mild flavor that is starchy and slightly sweet. But the taste is subtle.

The more noticeable quality is the unique texture. Cornstarch blocks have a solid, moldable texture when pressure is applied slowly. But they instantly liquify when hit with force. This is what creates the odd sensory play properties.

Here’s how cornstarch blocks are described texturally:

– Smooth yet grainy
– Soft and powdery
– Dry but slippery
– Cloud-like and foamy

The texture contrasts make it fun to squish cornstarch blocks between your fingers. But it may take some getting used to in your mouth as the solid melts into liquid. Most people find the texture strange but tolerable. Adding flavorings helps improve the taste appeal.

Choking hazards

While the texture of cornstarch blocks is odd, they are generally safe to consume, especially when mixed with other edible ingredients. However, pure cornstarch blocks do pose a minor choking risk, especially for small children.

Here are some choking hazard considerations:

– The powdery, grainy texture could cause coughing if inhaled while eating.
– The blocks liquify rapidly, which could be problematic swallowing a large mouthful.
– The slippery, slimy texture makes it easier for blocks to slide down the throat.
– Children may try to stuff large pieces in their mouth.

To reduce choking risks:

– Supervise young children closely during consumption.
– Avoid giant mouthfuls. Take small bites.
– Encourage thorough chewing before swallowing.
– Add extra liquid to help the blocks slide down more easily.

Additionally, anyone with swallowing disorders should exercise caution with this unique texture. But overall, cornstarch blocks pose minimal choking risks for most people.

Allergy risks

Cornstarch blocks are unlikely to cause allergic reactions, but it depends on what specific ingredients are used:

– Pure cornstarch is generally hypoallergenic. Corn allergies are rare.
– Water has no allergy risks.
– Additives like chocolate, peanut butter, or fruit could trigger food allergies. Avoid ingredients you’re allergic to.
– Contaminants like wheat are possible if using impure cornstarch. Opt for brands that are gluten-free.

So for most people, plain cornstarch blocks are low allergy risk. But monitor children for any signs of adverse reaction just in case. And modify ingredients appropriately for anyone with food allergies.

Nutrition when adding other ingredients

While plain cornstarch blocks lack nutrition, you can create more nutritious versions by mixing in energy-dense ingredients like:

– Nut butters – peanut, almond, sunflower etc. Add protein, healthy fats
– Chocolate – Cocoa powder adds antioxidants like flavonoids
– Seeds – Chia, sunflower for fiber, vitamin E, selenium
– Dried fruit – Raisins, cranberries, cherries. Add natural sugars and vitamins.
– Extracts – Vanilla, almond, mint. Flavor enhancers.
– Sweeteners – Honey, maple syrup, stevia. Swap refined sugar.

Here is the nutrition profile when 1/4 cup peanut butter is added to a batch of cornstarch blocks:

Calories Fat Carbs Protein
187 12g 11g 8g

As you can see, adding peanut butter provides significant protein and healthy fats, while still keeping carbs moderate. The possibilities are endless for creating nutritious edible cornstarch blocks by blending in energy-rich ingredients.

Making edible cornstarch blocks

Edible cornstarch blocks are simple to make at home:


– 1 cup cornstarch
– 1/2 cup water
– Optional: nut butters, cocoa powder, sweeteners, fruits, seeds etc.


1. Whisk together cornstarch and water in a pan. Add any extra ingredients like cocoa powder.

2. Cook over medium heat, stirring constantly until thickened to a dough consistency.

3. Remove from heat and allow to cool slightly before handling.

4. Once warm but not hot, knead dough on a surface dusted with extra cornstarch until combined.

5. Shape dough into blocks or any desired shapes.

The blocks will keep for 1-2 weeks stored in an airtight container in the fridge. Allow to come to room temperature before eating for the best sensory experience.

Serving ideas

Cornstarch blocks open up many possibilities for fun edible crafts or snacks:

– Cut shapes using cookie cutters. Decorate with icing, sprinkles or chocolate chips.
– Make creature shapes like snakes or worms. Add candy eyes and serve in dirt dessert cups.
– Mold dinosaur claw shapes. Dip in melted chocolate for ‘fossils’.
– Shape a smooth round ball then add features like wings to make an ‘owl treat’.
– Stuff pieces with chocolate chips or nut butters for a unique candy.
– Mix in instant pudding mix and crushed cookies to mimic edible ‘play dough’.
– Create diagrams of the human body parts kids can label and eat.
– Freeze small pieces on popsicle sticks into cornstarch popsicles.

The options are endless for crafting fun edible cornstarch blocks kids will enjoy. Let their creativity run wild! Just supervise to prevent overindulgence.

Storing and preserving

To retain the signature cornstarch blocks texture and prevent molding, proper storage is important:

– Store unused dough in an airtight container in the fridge up to 1-2 weeks.

– For longer storage, flatten blocks on a baking sheet and let dry fully. Once hard, break into pieces and store in an airtight container up to 1 month.

– To revive, add a teaspoon of water at a time and knead until pliable again. Add more water slowly as needed.

– Freeze flattened pieces wrapped in plastic up to 3 months. Thaw before eating.

– Refrigerate any play dough shaped creations and consume within 3-5 days.

With proper storage techniques, you can keep edible cornstarch blocks on hand for sensory play and snacking anytime.

Safety tips

When enjoying edible cornstarch blocks, keep these safety tips in mind:

– Check for food allergies before offering to children, especially common allergens like peanut butter or chocolate.

– Supervise young children closely to prevent choking hazards.

– Consume blocks in moderation as part of a balanced diet. They are largely carbohydrates with little nutritional value.

– Wash hands before and after handling to prevent spread of germs and bacteria.

– Ensure blocks are fully cooled before eating to prevent burns.

– Store unused portions properly by refrigerating or drying fully to avoid mold.

– Do not leave any play dough shaped creations at room temperature more than 2 hours.

Following basic food safety practices will allow enjoyment of edible cornstarch blocks while minimizing risks!


Here are answers to some frequently asked questions about eating cornstarch blocks:

Can you eat cornstarch?

Yes! Cornstarch is a common edible thickening agent used in cooking. Consuming small amounts of pure cornstarch is not harmful. It has some minor nutritional value from carbohydrates.

Why do cornstarch blocks liquefy when you hit them?

Applying sudden pressure to the blocks causes the cornstarch particles to lose integrity. The particles disperse in the water and no longer hold together in a solid state, allowing the blocks to liquify instantly.

Are edible cornstarch blocks safe for toddlers?

Yes, but supervision is important. The unique texture poses a minor choking risk for very young children. Limit portion sizes and encourage thorough chewing. Add extra liquid to help them go down easier if necessary.

How do you harden cornstarch blocks for storage?

Spread unused cornstarch block dough onto a baking sheet in a thin layer. Allow to dry out completely for 24-48 hours until hardened. Break into pieces and store in an airtight container up to 1 month.

Can you freeze leftover edible cornstarch blocks?

Yes! Flatten blocks and wrap well in plastic before freezing for up to 3 months. Allow to thaw before eating for the best reformed texture.

What happens if you swallow cornstarch blocks before chewing?

The blocks will rapidly liquify in the mouth and throat as you swallow. This could temporarily cause an unpleasant, slimy sensation but is not hazardous unless swallowed in extremely large quantities without chewing first. Take small bites and fully chew before swallowing.

Can you make sweet edible cornstarch blocks?

Absolutely! Mix in sweet ingredients like chocolate chips, peanut butter, honey, fruit purees, instant pudding mixes or powdered sugar to make sweet, candy-like edible cornstarch blocks. The possibilities are endless.


Cornstarch blocks are a unique edible substance that opens up endless possibilities for science experiments, sensory play, and snacking. While they may have an odd texture, cornstarch blocks made from food-grade cornstarch and water are completely safe for consumption.

Add nutritious ingredients like nut butters and fruits to boost the nutrition and flavor. Take safety precautions, especially with young children. Store creations properly to retain the texture. With a bit of creativity and supervision, enjoying edible cornstarch blocks can provide hours of edible entertainment!

Leave a Comment