wow, I had not considered keeping blackberries in a hydro setup. I am sure that it would work but not sure on how it will affect your question of quality.
I need to look that up if possible now. Normally, I prune them, water them and pick the berries. Basically treating it like an invasive plant that is controlled by watering and pruning.

Whatever you do do NOT plant blackberries in anything exept maybe a deep water culture because roots will take over anything and everything.

rrburk, I have also been looking into the possibility of overwintering blackberries using a greenhouse hydroponics setup. There is a lot of information to be found at Cornell's berry resource website regarding greenhouse production and hoophouse production. In addition, there is a post on this site under "hydroponic blackberries raspberries and blueberries" from a member who has been producing year round on the same raspberry canes for 4 years using poly bags! It is definitely possible, keep me updated on your successes

marklar
Is this the link to Cornell's berry resource website you were referring to?

berry resource website
http://www.fruit.cornell.edu/berry/index.htm

If so I didn't see a link to the "greenhouse production and hoophouse production"

homehydro,
Here are the links to the web sites, I found them through a google search, so I don't know their actual locations, but they have much information on controlled environment production for black and raspberries
http://www.fruit.cornell.edu/Berries/ghrasp.html
http://www.fruit.cornell.edu/Berries/bramblepdf/hightunnelsrasp2009.pdf

Thanks marklar,
That's the same website (I can tell from the URL), just different pages on it than what I found. Thanks, I bookmarked them, and saved the pdf to my computer. The pdf is 35 pages so I'll print it out later.

It wont be for a while, but I want to grow raspberry's, blackberry's and boysenberry's in the future. I'm especially real interested in the best way to obtain year round production. I know I will need a claimant controlled greenhouse, but it's my understanding they need a cold winter between crops. I'm considering rotating plants from a cold storage. After harvest cutting them back and placing them back in cold storage. Or would it be better to just clone new plants continuously, and trash the old ones.

homehydro,
You and I have very similar goals, I am also planning to grow raspberries and blackberries in a climate controlled greenhouse and want to extend fruiting and yield as much as possible.
As far as cold storage goes, I have looked into it but I don't want to deal with the added cost and labor associated with it.
What I have found in my research shows that primocane fruiting raspberries and blackberries (and I assume boysenberries) will continue to fruit until they reach a frost. That would mean that you could get yields year around on the same canes. If that doesn't happen, you at least have 2 full harvests the first year and you can harvest off of both primocanes and floricanes in the second year. I'm still unsure of whether this is the most efficient way to do it though, so there may be better strategies.
...also, if you have any helpful information let me know. Not many people are doing this right now and its kind of hard to find more than speculation

It is my understanding that the primo-cane is the first year growth, and fruits after winter in the so called second year (then called the flora-cane). Although an exception may be the ever-bearing varieties of raspberry (or primo-cane fruiting raspberries), that the first year primo-cane doesn't wait to go dormant before it fruits (the way I understand it anyway). I haven't really been looking into growing them lately because as I mentioned I wont be doing it real soon, so researching it has been on the back burner.

I spent a couple of hours researching it today, and like before there is a lot of information on growing raspberry and blackberries (boysenberries are just a combination raspberry-blackberry), but just not hydroponically. I did however find a lead on hydroponic production (Dr. Lynette Morgan) of them in an issue of the Growing Edge magazine. But you need to buy the issue to be able to read it (it's only $5). I did find that article in Google books that looks like it's complete (although it's in a "best of" issue), but I haven't figured out how copy it to a text file and print it out (so I will probably just buy the issue). I'll leave the links, as well as some others that might be of some interest.

For some reason this forum has blocked all links to the growing edge magazine (even links that are not live). So the best that I can say is that the article by Dr. Lynette Morgan is in the issue; Volume 12, Number 5, May/June 2001, and it's called "Growing Hydroponic Raspberries." Go to the Growing Edge website and do a search for "Growing Hydroponic Raspberries"

Google Books (Growing Hydroponic Raspberries)
Greenhouse Raspberry Production for Winter Sales
Organic Culture of Bramble Fruits
Pruning Raspberries, Blackberries and Gooseberries
OFF-SEASON PRODUCTION OF STRAWBERRIES AND RASPBERRIES
High Tunnel Raspberry Production, University of Minnesota
Growing Raspberries and Blackberries, University of Maine Cooperative Extension Publication
Pruning Raspberries and Blackberries in Home Gardens
How to Grow Raspberries (video)