**For a reliable everyday method, brew a measured hot concentrate, remove the tea, then dilute and chill it.** This gives you control over extraction and over how much the ice waters it down. For a gentler, less astringent drink, refrigerated cold brewing is also dependable.

Bags and loose leaves work with either method. The biggest differences come from the **type of tea, leaf size, water temperature, brewing time, and final dilution**.

**A repeatable hot-brew method**

For approximately 1 litre of black iced tea:

1. Start with **8–10 g of tea**, or the number of bags the package recommends for 1 litre. Bag sizes vary.
2. Pour **500 ml of freshly boiled water** over the tea in a heatproof vessel. Steep for **3–4 minutes**, or follow the tea’s instructions.
3. Remove the bags or strain out the leaves completely.
4. Add **500 g of ice** and stir. Any remaining ice counts toward the final litre as it melts.

If you want to refrigerate a pitcher for later, use 500 ml of cold water in step 4 and refrigerate it. Harney & Sons recommends the same basic approach: use the usual tea quantity with half the brewing water, then add cold water and ice. [Harney & Sons brewing guide](https://www.harney.com/blogs/news/how-to-brew-iced-tea)

**Make a stronger batch by increasing the amount of tea.** Extending the hot steep also increases bitterness and astringency. Remove the leaves before cooling so that extraction ends at a predictable point. [TeaSource preparation guide](https://www.teasource.com/pages/preparing-tea)

The methods you mentioned compare as follows:

| Method | Advantages | Drawbacks and controls |
|---|---|---|
| **Hot concentrate poured over ice** | Ready quickly; retains the character of hot-brewed tea; easy to repeat with measured quantities. | Ice dilutes it, so include that water in your recipe. Excessive temperature or steeping time can produce bitterness. |
| **Normal-strength hot tea, then refrigerated** | Simple; lets you use a familiar hot-tea recipe. | Takes time to cool. Ice added at serving makes it weaker, so use a little extra tea if you expect substantial melting. |
| **Cold water steep, refrigerated overnight** | Usually smoother and less astringent; requires little attention. | Takes hours; can taste less brisk or aromatic than a hot brew. Strain when it reaches the strength you like. |
| **Hot tea poured over one large ice block** | Cools and dilutes the tea through the same process as ice cubes. | A large block melts more slowly, making the cooling and dilution harder to predict. Cubes and measured quantities are easier to reproduce. |
| **Tea bags or leaves kept boiling** | Produces a forceful extraction. | Easily produces excessive bitterness in ordinary black or green tea. For these teas, heat the water, take it off the heat, and steep for a timed interval. |

**For cold brewing**, start with the same tea quantity you would use for that volume of hot tea. Add cold drinking water, cover, and steep **in the refrigerator for 6–12 hours**, then remove the bags or strain. Taste at six hours; let the next batch steep longer or use more tea if needed. Harney’s guide supports this method for loose tea, sachets, and bags. [Cold-brew instructions](https://www.harney.com/blogs/news/how-to-brew-iced-tea)

Choose your hot-brewing conditions according to the tea inside the bag or infuser. These are useful starting points; the package’s instructions take precedence:

| Tea | Hot-water temperature | Steeping time | Useful iced-tea approach |
|---|---:|---:|---|
| **Black** | 100°C / 212°F | 3–4 minutes | Hot brew for briskness; cold brew for a smoother result. |
| **Green** | 79–85°C / 175–185°F | 2–3 minutes | Cold brewing is forgiving; careful hot brewing also works well. |
| **White** | 79–85°C / 175–185°F | 2–3 minutes | Try cold brewing or a gentle hot brew. |
| **Oolong** | About 91°C / 195°F | 3–4 minutes | Both methods work; compare them with your particular tea. |

These temperature and time ranges come from [TeaSource’s brewing guide](https://www.teasource.com/pages/preparing-tea).

Finally, **“loose tea” and “tea leaves” usually describe the same ingredient**. Many conventional bags contain smaller pieces, which extract quickly; whole-leaf sachets behave more like loose tea. Give loose leaves room to expand in a large infuser or strain them after brewing. Weighing them makes successive batches more consistent than measuring by teaspoons. [TeaSource preparation guide](https://www.teasource.com/pages/preparing-tea)

Once you find a batch you like, record its tea weight, water temperature, steeping time, and final volume. Those measurements are what make the result repeatable.