I'm looking to brew a Sahti inspired ale with minimal hop bitterness. I'm going to use juniper berries and maybe some fir tips in the boil. I'm planning on dry hopping in the secondary for a little bitterness. Will that also help with preservation?
Dry hopping does not get you bitterness, it gets you aroma. For bitterness to develop the hop oils need to be isomerized by boiling or high temps in the wort (over 170F is the approximate cutoff for bittering).
Modern IPAs have moved away from bitterness in favor of juicy fruit flavors and aromas. But they do still taste bitter. What we're learning is that late-addition hopping and even dry-hopping can add substantial perceived bitterness. The reasons have funny names like hulupones, humulinones, and pol
If I'm reading the chart right it looks like 2 ounces in 5 gallon batch will be 15ish IBU.
As far as preservation, it'll probably help more than a beer with zero hops would. But that doesn't take much to accomplish that. Ethanol and pH handle most of the preservation. Hops will mainly suppress some lactic acid bacteria. Many beer spoilers can survive hops just fine.
Is there a way to calculate the IBU with only part of the fermentables in the boil and only about half the volume. I'm planning to add honey but don't want to boil it for flavor and I only have a 5 gallon pot. Brewers Friend doesn't seem to handle it right.