Smoked my first brisket today. Use an offset cooker. Kept temp 250 or below. A few times it spiked higher and I opened smoker to cool down. Cooked fast. Wrapped at about 4 hours in. Was done cooking in a hour. Thermometer said 210 But not sure it was in right place. Let rest wrapped in foil in cooler for almost 3 hours. Looked good. Good bark. Good smoke ring but it was tough and chewy not tender. Never really had a stall. According to sites I should be able to cook at 250 but it seems to me I may need to lower temp. Any advice?