Cooking sausages from frozen is usually fine (though some products should be thawed first, so check the packaging). It's a fast option, adding only about 50% more cooking time and not otherwise changing the process; that's generally just a matter of a few extra minutes. Only one of the three safe ways of defrosting sausages is comparably quick: microwave thawing. So, if you're in a rush and don't want to cook your frozen sausages – or the sausages are already cooked – that's the way to go.
Defrosting Sausages in the Microwave
Microwave thawing is the fastest safe method, but it does have some drawbacks. It can make already-cooked food rubbery, and it begins to cook raw food, which increases the chances of your ending up with an unevenly cooked or overcooked final product.
Also, because the food partially cooks, it's at risk for rapid bacteria growth, so you must finish fully cooking it immediately and before refreezing any unused portion. That means cooking red meat sausage to an internal temperature of 160 degrees Fahrenheit and any sausage containing poultry to 165 degrees F. If the sausage is already cooked, it should be eaten or refrigerated within less than two hours.
Use the microwave's defrost function if you trust it. For greater control – but requiring a little more involvement on your part – zap the frozen sausage at 50% power. Thawing time varies by microwave and by the quantity, shape, thickness, size and density of the sausage. Start at 1-minute cook time and check the sausage; then add time in small increments and re-check as needed.
Thawing Sausages in Cold Water
If you prefer not to use the microwave, you can safely defrost sausages relatively quickly by submerging them in cold water in leak-proof packaging. This may take 20 or 30 minutes for a single sausage or up to a few hours, depending on how much sausage you're thawing and its shape, size and density. If it's taking longer than a half-hour, replace the water in your bowl or pot with new cold water every 30 minutes.
Don't use warm or hot water in an attempt to speed up the process. The sausage may be in the temperature "danger zone" between 40 and 140 degrees F for too long. This leads to quick bacteria growth, even beyond the point that the food can be made safe to eat by cooking. And if the sausage is already cooked, you're at an even greater risk of foodborne illness.
Any raw meat thawed in this manner has to be fully cooked right away. It must also be cooked before it's safe to re-freeze any leftovers. Pre-cooked sausage should be consumed or refrigerated within less than two hours.
Defrosting Sausages in the Refrigerator
Just to cover all the bases, the third method of safely thawing meat is in the refrigerator. This wouldn't be considered a quick way to do it, though; sausage links or patties generally take around 24 hours to fully thaw.
If you plan ahead, this approach avoids the drawbacks of the other safe thawing methods. There isn't the same pressure to cook or eat the sausage right away. It can stay in the fridge for as long as it normally would (which varies from a few days to a few weeks or longer, depending on the type of sausage and whether the original packaging has been opened). Also, you can refreeze it within its safe storage time without cooking it if you need to.
Don't Thaw Meat at Room Temperature
As one final note, never thaw sausages by letting them sit out at room temperature. This takes hours (even longer than a cold water bath, because water conducts heat better than air). Meat can only safely be out at room temperature for up to two hours and only up to one hour if the environment's temperature is 90 degrees F or higher. You're setting yourself up for food poisoning by leaving frozen sausages out on the kitchen counter or table, even if you plan to cook them.