I did 2 loads of towels in my laundry today. First load, I used the last of the vinegar. For my second load of towels, I was out of vinegar, and the towels were washed exactly the same way but without the usual vinegar added. WHAT a HUGE difference! I never really noticed before. First load is soft. Second load is ...well....not. Actually they feel scratchy, it is a very noticable difference. Got to go stock up on vinegar!