If you shoot your finger against the side (like shooting away a cigarette bud) several times, then slowly rotate the bottle around it's axel while it's standing on a table several times, you can safely open them without them squirting all over the place. It truly works, also with shaken soda/beer cans.
What I do with these groceries is put them in a bag on my back or in my hand when cycling. The rack is for other stuff like veggies and other stuff that can handle the shaking or might get shitty when stuffed in a bag.
But you have a nice rack on your bike. Although it looks hard to take anyone on the back, unless they stand upright.
Microsoft: the biggest promoter for using Linux. "Our goal is to make Windows and it's apps so extremily repulsive even your grandma wants Linux instead. Because we care."