First time Brisket

[Habanero Smoker]

I only smoke flats that are untrimmed still in the cryovac, mainly because that is mostly what I can get, and I just don't like the point. At 152°F you did not give the collagen (connective tissue) a chance break down and to convert to gelatin. A lot of the moisture in the brisket is the gelatin that coats the protein fibers. I take my flats to 185°F.

[Pachanga]

Hawkeyesmokes,

I would agree with Pachanga. A small well trimmed flat is harder to cook and have come out perfect. If I was smoking one, I would use the method by WTS. (No offense intended Pachanga) Just think the moist sealed cooking will help with a piece of brisket like that. Now a whole packer, that's a horse of a different color! That is my favorite thing to smoke. And the thanks are to people like Pachanga and WTS.

No offense taken.  I have encouraged smokers to try more than one method to see which fits their temperament and taste.  While I prefer to smoke naked like most Texas Pit Bosses (some of whom were my mentors), I have stated before,

My wife makes a brisket (a trimmed flat) covered in the oven using liquid smoke.  It is a fall apart tender brisket and tastes great.

I started to recommend the WTS method of barbeque braising from the start but osumblues had already used a mustard slather.  My opinion is the slather would not do well with that method.  However, a trimmed flat can be barbequed naked and turn out great.  It just needs a little more TLC (and a 185 or higher IT).  I have had good luck with the water smoker effect of the Bradley and do not foil or boat.  However, the WTS method may be more forgiving on a trimmed flat for a new brisket smoker and the oven is a familiar tool for most. 

I am certainly in your school of thought on a whole packer cut.  That is by far my favorite brisket to barbeque.

osumblues,

Thank you for letting us know your final IT.  As Arnie and Habanero have already described, 152 is well below the temperature where the collagen and other connective tissues begin to break down.  Most briskets are ready between 185 and 195 IT in the middle of the flat.  There is no question that this was the the reason for the toughness.  As Habanero points out, that would also account for the lack of moisture.  The brisket did not have the benefit of the dissolved collagen converting to gelatin which gives a mouth feel of moistness.

I am sorry for the problems, but as you say, you learned a lot.  I hope to hear from you soon, smoking another brisket, untrimmed and larger.  When you get it right, it will be a pleasant experience to be enjoyed by many.  After that, riding that horse will be easy.

Good luck and better smoking,

Pachanga