When adjusting recipes for high altitude there are some basics I follow. To counter the effects of low pressure and low humidity, science comes to the rescue with these alterations:
- For each tsp of baking powder, reduce by 1/8-1/4 tsp
- For each cup of sugar, reduce up to 2 TBS
- For each cup of liquid, increase by 2-4 TBS
This information is for bakers at 6500 feet and can be found at the following link written by the Colorado State University Extension: High Altitude Food Preparation.
You can find info for other altitudes at this link, as well as more scientific explanations and specifics of certain baked goods.
The science may appear daunting to those who just want to eat cake. But a few moments of math can help make the cake (or cookies or bread) taste and look better. It’s well worth it.