A study done in July 2008 found that in blind tests (i.e. if the eaters did not know whether they were eating "standard" or free-range chickens) the free-range chickens were actually found to be less preferred in terms of taste.
They compared chickens that had been raised by "standard", maize-fed, free-range and organic production systems.
Taste panel assessments were made using 8-point category scales of texture, juiciness, abnormal flavour, flavour liking and overall flavour.
Fillets from birds reared in the standard system were rated by the taste panel as more tender and juicy. There were no significant differences in chicken flavour. Based on hedonic assessments of flavour liking and overall liking, by a small panel of assessors, meat from birds produced in the standard system was most preferred and that from organic systems the least preferred. Meat from free-range and maize-fed systems was intermediate in preference. This result reveals a trend, but does not infer consumer acceptance.
(emphasis mine)
In the course of tracking down the above study, I found a few people blogging about their own blind tests. Obviously, these don't have the rigor of a scientific study, but they do include control groups and blind testing.
- This person cooked four chickens (three free-range and one normal) and concluded there was "no noticeable difference in taste" and family members (who tasted blind) "unanimously said that it all tasted the same".
- Two chefs did a side-by-side test of free range vs mass-produced chicken and found "no appreciable difference in flavor". If anything, they noticed that the industrial chicken had "a marginally juicier and tenderer consistency".
So the conclusion seems to be that free range chicken does not taste better and if anything tastes worse.
However, it's worth noting that we don't actually eat things blind. (Well, you might if you were eating at a friend's house and they didn't tell you the type of chicken you were eating - but not in your own kitchen.) We are influenced by brand names, product descriptions and price. If you know you're eating a free-range chicken, it may actually taste better to you. This is completely subjective and unscientific, but... does it matter?
Furthermore, there are plenty of reasons for wanting to eat free-range chickens besides taste - the main one of course being concern for the welfare of the animal. If this is something important to you, it might even contribute to your subjective tasting from the previous paragraph. This is all1 speculative, of course, but I mention it as a caveat to taking the scientific findings as a rule for what chicken to eat, not as justification for an opposing rule about what chicken to eat.
1"all" =final two paragraphs