ok here is what I have been told.... the t storms can affect the tomato portion by changing the acidity( or something to that effect) but in reality I have had no problems. I have made soup on rainy days this year with no ill effects. That is to say the lighting was not directly overhead. I say just make the D@#$ soup. More importantly is to use crab stock from the shells and use fat back/ boiled ham hock as stock. Just using plain water is not the way to go. also if you want it to taste better let it sit for a day in the fridge to let everything meld. The caveat to this is if it is a huge batch (last time I made it was for a family reunion so I ended up filling my crab steamer pot to the brim 36-40qt.) it must be cooled quickly or it runs the risk of spoiling. so it may be best to split it into smaller portions.
I made 8 gallons of home made crab soup 2 days before a friends rehersal dinner that I catered...It stormed like a big dog the day I made it AND the next day, the soup was the best most of the people there had ever eaten....47 people ate all but 2 gallons of it....
Fact,
Has happened to me...more than once...4th of July being the latiest. Perhaps it's something I put in mine that others do not...not sure...........but it will sour in a thunderstorm......and it will happen to you guys eventually. Just a thunderstorm.....rain has no effect....don't ask me why, I do not know.
I asked the same question the last time this issue came up. How close must the storm be? Is thunder in the distance all that is needed? What about 'heat lightning' on those hot summer nights? Does it make a difference if its Cream of Crab or Maryland Style? Is imported crab immune from this?
I'll bet that a direct strike might have some effect, but I have a real problem believing that a thunderstorm can cause any measurable effect on crab soup.
This is not know to be fact, just what I have heard from the old timers I worked for at Brownie's Crab House back in the 80's,
The sudden change in barometric preasure causes the cabbage to ferment. A lot of people don't use cabbage in their crab soup so they will never experience this.
Like I said, I do not know the answer, this is only what I have heard as an explination......