Most everyone that I have talked to that does not like said that it is the bitter taste they don’t like. Fresh is never bitter. In fact, fresh is smooth and tasty even undoctored. So what is giving such a bad rap? After some research it a cured to me that the problem is lack of freshness, and that was brewed hours ago. Stale itself is horrible to drink. Stale can leave a bad taste in your mouth, but if you buy that is guaranteed fresh when you brew it then it will taste smooth and refreshing. How does get to the point of being stale? In many cases it is due to poor packaging, but in most cases it is due to over stocking.
Poor packaging is when the product is not properly sealed from the manufacture, or the seal is broken along the way. Most containers are plastic these days, but many still use the steel cans. The difference is the cost plastic is much cheaper to produce. Plastic is not as durable and sometimes is easily damaged. If the seal is broken then the is exposed to the air, which dries out the coffee. This is the main reason gets to the point of being stale. Another problem is over stocking.
When a store over stocks there products the product sits longer on the shelf or in the back and over time the freshness fades away. Many distributors of buy by volume to get the at a cheaper price. The problem is they can sit on that for month, or even years until it is sold. How long can remain fresh in a vacuum-sealed container? It can vary, but the average length is about 6 months. Do you see the problem now? I have worked for a grocery store before and I have seen products stay on the shelves for months. If you were to brew a cup of from beans roasted a year ago then that cup of will be horrible. What about that was brewed 4 hours ago?
In many cases the appears thicker because the water is vaporized over time. The can have a burnt taste that is also bitter. If it is not fresh don’t drink it. My wife hates because of her first bad experience, and after I roasted her a fresh batch she admitted that it was really good and not bitter. How fresh is your coffee?