There are two types of bagels in this world: Real, honest-to-goodness bagels, and round bread. Round bread is what you find in the bread aisle at your local supermarket; real bagels are sold at bagel shops and are usually made on premises. If you’re buying a bagel at a real New York bagel shop, you better not asked for it toasted.
Here’s why: A fresh bagel is prefect as it is. The outside is slightly crunchy and chewy thanks to it being boiled, and the inside is soft and bready, ready for toppings. A fresh bagel doesn’t need to be cooked again; doing so ruins the integrity that the bagel-maker worked so hard to perfect.[related]
“A good bagel in its perfect form — that is to say, fresh from the oven — does not require toasting. It does not benefit from toasting. Toasting a good bagel is bastardizing a beautiful thing. If you’re toasting a good bagel, you’re toasting something that’s already warm and crusty — that’s redundant. You’re not going to get anything better than peak form — oven-fresh. The outside is already crisp yet pliable. The inside, willing and giving, accepting and forgiving, still able to transform through its residual heat, its breath — your spread, from its natural state into something just slightly different, while keeping its integrity. If you’re taking this level of craftsmanship and toasting it you either have hubris or a lack of experience with quality product.
There is nothing wrong with toasting an average bagel, a day-old bagel. Go ahead, freeze your bagels and then toast them. By all means. But a fresh bagel? … No. And here’s the thing, those bagels, those bagels acceptable for toasting? The frozen ones, the hours-old bagels, the day-olds, the second-time rounders? You keep them. They’re not worth eating if you have to toast. If you’re toasting a bagel worth eating, you’re not just painting a moustache on the Mona Lisa, you're spitting in Da Vinci's face.”