I just brewed a dead ringer extract kit and it is now in the fermenter. I just realized I was 1 lb. short on the liquid malt extract. Is there anything I should do now that it’s in the fermenter?
How long has the beer been fermenting. If active fermentation has been ongoing for a couple days I would leave it as is. You’ll still have a +6% beer. If the yeast is still in lag phase the LME could be dissolved in a quart of boiled water, cooled, aerated and pitched.
Leaving it as is will still give you a very good IPA.
You can add additional fermentables almost anywhere in the process. I sometimes start a batch out at a lower O G so I can use less yeast at the start then add more once it’s fermenting.