Igloo 1-Gallon Cooler (Open-Top Method) -- Clearest Block
Fill a small Igloo cooler with water, leave the lid off, and set it in your freezer. The insulated walls force freezing to happen from the top down, pushing dissolved gases and impurities toward the bottom. exactly how commercial ice is made. The result is a remarkably clear, dense block that you can trim with a serrated knife. Once frozen, flip and run warm water over the outside to release. This method requires no special purchase if you already own a small cooler, making it the best value approach for serious clarity.
Check price on Amazon →Make large, slow-melting block ice at home with the right container. We compared silicone molds, food-grade buckets, and specialty trays to find what delivers.
Block ice melts far slower than cubed ice, makes cocktails taste better, and is essential for long cooler trips. The secret to a good block is the container. size, material, and insulation all affect clarity, density, and ease of release. We froze dozens of blocks using different setups and ranked the best options for home use.
| Product | Best For | Rating |
| — | — | — |
| Igloo 1-Gallon Cooler (open-top method) | Clearest block ice | 4.9/5 |
| Tovolo King Cube Tray XL | Cocktail-size blocks | 4.7/5 |
| RTIC 1.5 Gallon Ice Bucket with Lid | Large blocks for coolers | 4.6/5 |
| Winco 6 qt Square Food Container | Budget large block | 4.5/5 |
| Libbey Glass Loaf Pan 2.2 qt | Log-style blocks | 4.4/5 |
Our testing process
We compare every pick against the field on real specifications, certifications, and aggregated owner reviews. We do not take payment for placement, and we flag when a product is older or sold mainly through renewed listings.
Quick comparison
| Pick | Best for | Score | |
|---|---|---|---|
| Igloo 1-Gallon Cooler (Open-Top Method) -- Clearest Block | Check price | ||
| Tovolo King Cube Tray XL -- Best for Cocktails | Check price | ||
| RTIC 1.5 Gallon Ice Bucket with Lid -- Best for Cooler Blocks | Check price | ||
| Winco 6 qt Square Food Container -- Best Budget Large Block | Check price | ||
| Libbey Glass Loaf Pan 2.2 qt -- Best Log-Style Ice Block | Check price |
Reviewed in detail
Igloo 1-Gallon Cooler (Open-Top Method) -- Clearest Block
Fill a small Igloo cooler with water, leave the lid off, and set it in your freezer. The insulated walls force freezing to happen from the top down, pushing dissolved gases and impurities toward the bottom. exactly how commercial ice is made. The result is a remarkably clear, dense block that you can trim with a serrated knife. Once frozen, flip and run warm water over the outside to release. This method requires no special purchase if you already own a small cooler, making it the best value approach for serious clarity.
Tovolo King Cube Tray XL -- Best for Cocktails
The Tovolo King Cube XL produces 2-inch perfect cube blocks ideal for whiskey, bourbon, or any spirit where dilution control matters. Each cavity holds enough ice to fill a rocks glass, and the silicone construction means the blocks pop out cleanly without flexing the entire tray. The lid prevents freezer odors from penetrating the ice. At roughly 16 cubes per tray, it's efficient for entertaining. The silicone cleans easily and lasts for years. If you want individual serving-size blocks rather than one giant slab, this is the top pick.
RTIC 1.5 Gallon Ice Bucket with Lid -- Best for Cooler Blocks
RTIC's food-grade bucket produces a large, round block that fits most standard coolers and melts very slowly thanks to its density. The wide opening lets you add water without splashing, and the bucket's high-density polyethylene construction is odor-neutral and BPA-free. To release, soak the exterior in warm water for 60 seconds and the block slides out cleanly. The lid reduces freezer burn on the ice surface during the freeze cycle. This is the most practical pick for camping, fishing trips, and weekend cooler use.
Winco 6 qt Square Food Container -- Best Budget Large Block
The Winco square food container is a restaurant industry staple repurposed beautifully for home block ice making. Its flat walls produce a rectangular block that stacks efficiently in coolers and is easy to score and split. The polycarbonate construction is crystal-clear so you can monitor freeze progress, and it tolerates freezer temperatures without becoming brittle. The lid creates a clean top surface. At it's the most affordable path to a proper large block without improvising with random containers.
Libbey Glass Loaf Pan 2.2 qt -- Best Log-Style Ice Block
A standard glass loaf pan produces beautifully shaped ice logs that fit perfectly into ice buckets and barware. The Libbey 2.2 qt loaf pan's straight sides make for clean, uniform blocks, and the borosilicate glass means there's zero flavor or odor transfer. Log-shaped blocks look professional in punch bowls and wine chillers. Release is easy. a brief warm water soak pops the block free. Note that glass is heavier and more fragile than plastic for this use, but the aesthetic result is second to none.
How to choose
What to consider
The three variables that matter most are size, material, and insulation. For cooler use, choose containers holding at least 1 gallon. smaller blocks melt too quickly in a full-size cooler. Food-grade HDPE, polycarbonate, or glass are the safest materials; avoid thin plastics that may crack when frozen. Insulated containers (or the cooler method) produce clearer ice by controlling freeze direction. Straight, smooth sides and a wide opening make water filling and block release much simpler. If clarity matters most, choose the cooler method or boil your water before freezing.
What to consider
For more kitchen organization ideas, see our [best cooler accessories](/articles/best-cooler-accessories) guide. Learn how we test and score products at [/methodology](/methodology).
Common questions
Insulated containers that freeze ice from the top down produce the clearest blocks because they push air bubbles and impurities to the bottom. A small Igloo or Coleman cooler left open in the freezer works extremely well. Slow freezing is the key. rapid freezing traps air before it can escape, resulting in cloudy, opaque ice. Boiling water first also reduces dissolved gases for cleaner results.
A standard 1-gallon block takes 18-24 hours in a typical home freezer. Larger blocks (5+ gallons) may take 48-72 hours. Slow, directional freezing in an insulated cooler produces better clarity and denser ice that melts more slowly. Check at 24 hours and return to the freezer if the center is still liquid.







