my cider has too little 'bite'. It taste a bit sweet, and lacks bite. It has an alcoholic content of 5% by volume which I don't really want to change much. Should I be looking at different strains of yeast, different apples, or take a look at my whole productionline? I have tried different blends of apples, but none so far have generated a good result.
Many orchards in the Midwest that grow mostly dessert apples will often blend in a small percentage of crab apple juice. This will increase the acidity level, tartness and tannins in an uninteresting base cider. I have also used liquid wine tannin in small amounts to give the store bought cider some character. You can also use tartaric or malic acid after fermentation to lower the pH and offset the sweetness and brighten the flavor.
What kinds of apples are you using? You could use additives to fix a batch but it's better to start out with a blend of apples good for making cider.
Newtown Pippin makes a good single variety cider. My current batch on tap is a blend of Newtown Pippin, Black Twig, and royal gala. I split the batch and fermented it with two different yeasts. Half was wlp775 the other half was white labs sweet mead yeast. The 775 is full of bite,a bit sharp for some (I like it) The mead yeast is more well rounded. It's less sharp but has noticeable tannins that are missing in the other batch. Te biggest impact is going to be the blend of apples and the yeast.