The problem with RO water is its lack of minerals. It has nothing to do with your gushing beers. The gushing of warm beer is simply due to the fact that CO2 is more soluble in cold liquid than warm liquid. Thus, when warm, the excess CO2 immediately comes out of solution when you uncap it. Thus the gusher.
The lack of minerals do cause some other problems. With the high ph and lack of calcium, you won't get as good conversion in the mash and your efficiency will suffer a little. Also, the various minerals (or lack thereof) will affect the flavor of your beer. John Palmer does discuss this in detail in the water chemistry chapter in www.howtobrew.com
. Some minerals such as the sulfates will emphasize the hop bitterness. Others will have other effects.
I do make use of RO water in all my all grain brews. This is because my tap water is very high in carbonates. I cut my tap water 50/50 with RO water for most brews to bring the mineral content to acceptable levels. For very light beers such as pilsners, I use 75% RO water.
You really should use at least some percentage of tap water with the RO or add minerals to your water. In order to know where to start, you should contact your local water utility and request a water report on the tap water. These are normally free (or available for the cost of copying) since these are public records. In my case, I had to talk to 3 different people including the city engineer since no one had ever asked for one of these before. It took them a while to find the latest report.
If you decide not to use any of your tap water, then you need to doctor the RO water yourself. Here is a handy chart to help you know what to aim for. http://ourworld.compuserve.com/homep...e/waterqal.htm
Figuring out how much of what to add can be a little tricky. You need to use something like BreWater 3.0 to figure it out. This calculator can be found at http://home.elp.rr.com/brewbeer/
Hope this helps out a little.
Bugeater Brewing Company