Worse, those lemons aren’t fully ripe. Of course you’re adding sugar anyway but they’re going to be low on juice and possibly bitter, so be sure to taste before you ruin other ingredients. Storebought lemons are often dyed so you needn’t try for that look, but at least half of the skin should be a clear bright yellow. And they should twist off without a stem. Lemons ripen slowly, and they keep well on the tree, so you shouldn’t have a bunch like this unless a storm or something brings them down or a branch breaks.