Where Did I Go Wrong?

[Old Glory]

I SV Tri-Tip for 2-2.5 hours at 129 then dry off and immediately sear. Always comes out great.

[TripleB]

Sometimes it’s just the meat and not what you do. I’ve cooked steaks where the marbling was ok and the steak came out so tender and flavorful. And I’ve done steaks that were gorgeous with great marbling, but came out just ok. My method and technique for both was the same.

[cashelton]

I think Uncle Bob is on to something...I have the same experience with skirt steak. Every time I buy skirt steak fresh and season the meat, the outcome is disappointing. If I buy packaged fajita skirt steak it always comes out great.

[radshop]

Costco blade tenderizes a lot of the meat they cut in-house, but the marinated tri tips are vendor sourced, mostly these from what I've seen:

https://www.billbaileys.com/product/santa-maria-style-tri-tip-beef-sirloin-roast/

It's not labeled as blade tenderized nor as having bromelain in the ingredients. I'm not an expert on US food labeling laws, but they are lax in certain respects. The label might not tell the whole story.

In my opinion, what you did wrong was to blame yourself on the basis of 1 cook comparing meat from different sources prepared differently. Too many variables.