What size of asparagus is you use? I like mine to be about the size of a "sharpie" not a "highlighter", although including a few of the larger size is acceptable. Having all the jars filled with the asparagus and spices then pouring the boiling brine over and move them at the same time into the simmering/low boiling water bath as quickly as possible. Bring the batch to a rolling boil to start the processing time. Timing is tricky but it helps to manage it so the asparagus doesn't spend too much time in the hot/boiling brine.

Thanks canfan! Most of the spears were about 1/2" or so. I did pack the jars and fill with the brine 5-10 minutes prior to the BWB coming to a rolling boil so they did sit in the hot brine for awhile before processing so I think you may have hit the nail on the head. It's about time to shut the harvest down for the year as the main bed is only on it's 4th year. I'll try to remember your good advice for next year.

The pickle crisp may help as well--it does a good job with keeping dilly beans from turning to complete mush during my high-altitude longer canning times.

Today I am trying the pickled asparagus for the first time using the "Joy of Pickling" recipe and her directions give the option of pasteurizing at 180-185 for 30 minutes. Though it will be a few weeks until the pickle is ready to sample, I have had good results retaining crispness with pasteurizing cukes for pickles, so I am hoping for similar results with asparagus.

Here's a link to an earlier thread on pickling asparagus where a poster includes the recipe.
Previous thread on pickled asparagus