How to Clean and Sanitize Toddler Cups and Straws

By Cosco Kids US Official Site | Car Seats, Strollers, & Baby Gear | Published: 2026-10-17

Category: How-to Guides

Learn the best way to clean and sanitize toddler straw cups, including dishwasher-safe options and how to prevent mold buildup in straws.

Quick Answer

To clean toddler cups and straws effectively, disassemble all parts and rinse immediately after use. Wash with hot soapy water or place dishwasher-safe components on the top rack. Sanitize weekly by boiling or using a steam sterilizer to prevent mold growth inside straws.

Why Thorough Cleaning Matters for Straw Cups

Straw cups have small crevices where milk, juice, or formula residue can hide. If not cleaned properly, this residue can lead to mold growth inside the straw or under the valve. Mold in straw cups is a common concern for parents, but it's entirely preventable with the right routine. The key is to clean every part after each use and to sanitize regularly.

Daily Cleaning vs. Weekly Sanitizing

Daily cleaning removes food particles and bacteria. Use a bottle brush to scrub the straw and valve, then rinse thoroughly. For a deeper clean, sanitize straw cups once a week using a baby bottle warmer sanitizer or by boiling parts for five minutes. Sanitizing kills lingering germs and mold spores that dish soap alone may not remove.

Step-by-Step Cleaning Routine for Toddler Straw Cups

Disassemble All Parts: Separate the cup body, lid, straw, valve, and any silicone seals. Rinse each piece under warm running water immediately after use to remove leftover liquid. Common mistake: Leaving the cup assembled traps moisture and bacteria. Always take it apart fully.
Wash with Hot Soapy Water or Dishwasher: Use a bottle brush to scrub the inside of the straw and the valve. For dishwasher-safe trainer cups, place small parts in a mesh basket on the top rack. Avoid high heat settings that could warp silicone. Check the manufacturer's instructions to confirm which parts are dishwasher safe. Most silicone straws and lids are top-rack safe.
Sanitize Weekly: Boil the disassembled parts for 5 minutes, or use a steam sterilizer or baby bottle warmer sanitizer. Allow parts to air-dry completely on a clean towel before reassembling. Sanitizing is essential for killing mold spores that can grow in damp straws. Do this at least once a week, or more often if your child uses the cup for milk or juice.

Products That Make Cleaning Easier

Bluey Weighted Straw Trainer Cup, 7 Oz [Y11886CA1]: The Bluey Weighted Straw Trainer Cup has a weighted silicone straw that stays in the liquid for easy sipping as your baby learns to drink. The weighted straw design means the straw tip is always submerged, but it also means you need to clean the straw thoroughly to prevent residue buildup. This cup is dishwasher safe, making daily cleaning convenient.
Squeeze & Sip® Silicone Straw Trainer Cup, 7 Oz — 2 Pack [Y12155AZ1]: The Squeeze & Sip Silicone Straw Trainer Cup helps little ones learn and then lives on as the perfect-sized cup for them to sip from. It's simple: just give the cup a gentle squeeze to start the flow. The squeeze mechanism introduces liquid into the straw, which can trap milk or juice. Disassemble the silicone straw and valve after each use, and sanitize weekly to keep the cup fresh and mold-free.