Gravity is just a measure of how much sugar is in the wort, so am I right in assuming that if I want a higher OG, I should increase the amount of malt i use relative to the amount of water? That seems logical, but I’m perusing some recipes that really seem to load up on malt and then expect relatively lower OGs than I’d expect.
I did a 1-gallon extract batch with 1.2 pounds of amber DME, plus steeped with a cup of crystal 60. That measured at 1.080 OG and 1.020 two weeks later. But, like I said, I see recipes that seem to use even more malt than that and expect lower. Those are mashing recipes, not extract. Maybe that makes a difference?
Yes, all grain and extract are different. A lot of all grain malt goes into making a small amount of concentrated extract. By comparing, you’re kind of doing apples to oranges. Most recipes I find in magazines, etc, have two versions- an extract version and an all grain version.
There are limits to how high a gravity you can do. Really big beers will require an alcohol tolerant yeast and the wort will need lots of O2. 12% ABV is about the limit for beer yeast. Those crazy beers you see like https://www.brewdog.com/item/15/BrewDog/Tactical-Nuclear-Penguin.html are concentrated by freezing the finished beer and removing the ice.
On the other end of the spectrum a very low gravity beer will require some adjustments so it doesn’t taste watery. The “session” beers that are around have more hops and non-fermentable grains to make low alcohol beers have some taste and body. Personally I don’t like them and can’t see the point. I’d rather have one Barley Wine than five session beers.
So back to your question. Yes add more malt, get higher gravity. You will want to experiment with the hops and specialty grains though to keep it balanced.