You have several options:

1) A pre-stain conditioner. This can be a canned product (see this article

2) Gel stain approach

3) A thinned coat (aka spit coat) of shellac or thinned coat of hide glue (aka Glue Size) will also restrict the penetration of stains and result in a lighter application.

4) You can thin down the intensity of a stain by mixing with the "natural" (i.e., no color) stain base.

Sorry, I thought the problem was more intensity that redness. To address too much red:

First, run a trial with your top coat of finish. This often tones things down.

To kill red, you apply green (its color opposite). In the stain palette, this is usually raw umber. God knows what the stain manufacturers might call this. You might ask the paint store to give you a squirt or two of raw umber UTC in a jar you've taken in.

One of the stains I use can be a shocking cordovan color on some woods. A treatment with brown glaze really settles it down.

In short, you are going to have to run some test panels, through to completion, to find the best solution.

Thanks for the info. I was also looking to hear from those that have stained Alder and other woods and see if what I'm experiencing is "normal" in that Alder tends to take stain more red than some other woods (e.g., Hemlock and Red Oak).

I only have a small test piece of Alder to stain that I got at a lumber yard, wanted to play around with stain on Alder before committing to buy all of the interior doors in my home in Knotty Alder. :-O

bump!

Alder is a much more absorbent wood then oak, don't know about hemlock. It's also used as a substitute for cherry. So I believe the results you're getting are about right for the species. As stated before, try a conditioner and/or thinning. This will be a trail and error thing.
Ron