Scaling chai is not simply multiplication. Larger volumes behave differently — heat distribution is uneven, milk scorches more easily, and the spice balance that works for two cups can become overpowering for twenty. This guide addresses each of these challenges.
The Golden Ratio
For large batches, the ratio shifts slightly toward water. Where a single serving uses 2:1 water to milk, a large batch works better at 2.5:1 — the extended cooking time concentrates the flavour enough that you do not need as much milk.
Add the milk only in the last 5 minutes of cooking. For large batches, milk added too early will scald and create a skin that makes straining difficult.
Method
Step 1. In the largest pot you have, combine all the water and spices. Bring to a full boil over high heat.
Step 2. Reduce to a medium simmer and cook for 10 minutes. Your kitchen should now smell extraordinary.
Step 3. Add the loose-leaf tea. Simmer for 4 minutes — no more, or it will become bitter.
Step 4. Add the milk and sugar. Stir to dissolve the sugar. Bring back to just below a boil over medium-high heat, stirring occasionally.
Step 5. Strain through a fine-mesh sieve (or muslin cloth) into a large serving vessel. Serve immediately.
Keeping It Warm
If you are serving over an extended period, keep the strained chai in a large thermos or slow cooker set to "warm". Do not keep it simmering on the stove — it will continue to extract tannins from any remaining tea particles and become bitter.
“The best chai party trick: make it 20 minutes before guests arrive, strain it into a large thermal jug, and serve it as if it were effortless.