I was wondering what would be the results and side effects if I double every ingredient of a recipe and made 4-5 gallons of wort rather than the 2-2.5 normally called for. Would this give me a more flavorful stronger beer such as a double IPA or double stout and increase the ABV?
You can do this and you’ll find that some recipes are kind of this way anyway. In some cases you might even want more specialty grains in the bigger beer, as a percentage of the total grist. On the other hand, sometimes a bigger beer needs more base malt to get it to finish dry enough. All depends on what you want. Take a 1.040 beer that would finish at 1.015, double it and you’d have 1.080 finishing at 1.030. That would be a little too sweet.
Another thing to keep in mind is you should prolly use a yeast starter with a beer with a sg that high.
oh and to keep to the multiple blowoff thread theme, use a blowoff tube. Thats a lot of fermentables to get rockin and rollin.