The most important factor to smoking a good brisket is starting with a good brisket. Usually this implies things like an even flat muscle, avoiding shoddy butcher work, a trimmable fat cap, etc.
Some people even think that left brisket tastes better than right (trust me, they taste the same).
Soon enough you'll find yourself deciding between USDA Choice and USDA Prime for your briskets and ask yourself whether Prime is worth the extra $1-$1.50 per pound.
The short of it: In my opinion, choice grade is the perfect balance of price and intramuscular fat and Prime brisket isn't markedly better.
Before deciding between the grades, it might be a good idea to understand the United States Department of Agriculture's (USDA's) Rating system.
The inspection of meat for wholesomeness is mandatory and is paid for by tax dollars. The grading of meat for quality is a service requested and paid for by meat and poultry producers/processors.
The main factor that separates all quality grades is marbling, or the fat dispersed in the lean meat of the ribeye muscle.
Note: A ribeye muscle that is graded as "Prime" also means the rest of the cow is also prime.
There are three quality grades:
As someone who has smoked both prime and choice briskets over the years, I can say without a doubt, Choice has more than enough intramuscular fat.
The main thing that separates Choice and Prime is the price. Assuming a whole packer brisket weighs 8-20 lbs, you can expect to pay anywhere from:
The above uses Wild Fork Foods brisket prices. As of writing this article, whole USDA choice brisket is $3.98/lb and prime brisket is $4.98/lb.
So you're essentially paying anywhere from $8-$20 more for brisket that won't taste markedly better.
Note: Wild Fork Foods sells the choice briskets as whole (deckle on) - where-as the prime briskets come with the deckle off. Meaning, they save YOU money by not charging you for fat.
This is typically not the case in a grocery store if you have briskets readily available to you; I personally don't.
While it can be hard to express over the internet the taste, tenderness, succulence, etc. of food, pictures tend to tell the story better.
This is a photo of a Choice Brisket I smoked from Wild Fork Foods:
If that isn't enough juiciness for you, then upgrading from choice brisket to prime is probably worth it for you.
I don't tend to buy prime briskets much anymore because there isn't really a benefit to doing so. However, I bought one for July 4th (technically the 3rd, but smoked overnight) just for the sake of this article and for You, the reader.
Here is the cross section of the prime brisket:
To me, there isn't much of a difference in terms of flavor output, juiciness, tenderness, etc. All factors that are used to separate choice and prime meat.
In my opinion, select grade brisket lacks the intramuscular fat that's required for brisket to stay moist after a 12+ hour long cook. This is readily apparent after you've trimmed the surface fat and silver skin.
Most folks would agree with me that select grade brisket has a tendency to even dry out.
In order to combat this, some folks have even gone to the extent of injecting select grade brisket with beef tallow to help compensate for the lack of fat.
Both the briskets above were smoked with Morton Kosher Salt, Freshly cracked black pepper, and Lawry's seasoned salt and were both trimmed the same way.
Both were smoked on my Weber Kettle (separate days). At around 175F (near the stall) I transferred them to my Masterbuilt electric smoker in a foil boat till the point and flat were probing 200-205F and were probe tender. I then held both overnight at 145F in my electric smoker for slicing in the morning.
To reiterate, if you feel the $8-20+ price per pound results in a brisket that is markedly better, I'd encourage you to stick to prime briskets.
My personal opinion after smoking hundreds of briskets is that there isn't a significant difference to warrant buying prime brisket. Choice brisket has more than enough fat to keep the brisket from drying out over the 12-15 hour cook.
With that said, if prime briskets are cheap where you live, by all means - buy a prime brisket.