I have recently brewed a nice rye ale. It turned out very nicely, however, compared to all the other beers I've brewed, it has a really syrupy texture and thickness to it. It quite dry but it isn't strong, ABV is 5.5%. The main malts were pale, rye and some wheat.
So I was wondering - what are general influences on the thickness of a beer? Is it just the malts (I'd guess the wheat malt is at least somehow responsible for parts of the syrupiness)?
Using today's highly modified malts, mash temp makes a lot less difference than it used it. I'd say it's the rye. I have made many, many rye beers and as the % of rye rises, the beer gets a thicker, more intense mouthfeeel.
Generally the temperature of the mash can give a thicker consistency to the beer as you move from 63-68 degC for you mash temperature the high you go the more dominant alpha-amylase will be. This cleaves off unfermentable tri-saccharides (three unit sugars) which give a full mouth feel, where as beta amylase which is most active ~63-64 degC cleaves single glucose molecules off the starch chains, giving highly fermentable wort and thinner bodied beer.
Also sometimes diacetyl can lend a buttery/butterscotch like syrupy feel to the beer.
