Most common questions used to investigate
Did you spend enough time kneading the dough?
Did you add salt and yeast at the same time?
Did your dough have enough time to rise?
Is the temperature in your kitchen under 60 degrees or over 90 degrees Fahrenheit (15-33 Celsius)?
Did you check that your yeast is alive (yes, yeast is a collection of living organisms)?
Common conclusions
Under-kneading your dough will cause your bread to be dense. Spend at least ten minutes kneading your dough in a mixer or twenty minutes if you are using your hands.
Salt can affect the yeast, causing your bread to be dense. Don't create direct contact between the salt and the yeast. Instead, try adding the salt after the initial mix of ingredients.
Bread that has not risen enough will come out dense. After the first rise, knead the dough again for a few minutes then set it aside and let it rise again until it doubles in size.
The wrong temperature can affect your yeast causing the bread to be dense. Make sure your kitchen is the temperature in your kitchen between 60 degrees to 90 degrees Fahrenheit (15-33 Celsius).
Your yeast must be alive in order for your bread to rise. Keep your unopened yeast in a dark dry place and use before expiration date.
Unfortunately, we were unable to determine why your bread is so dense.
References
https://thebreadguide.com/bread-dense-as-a-brick/
https://mikeswindow.com/notebook/5-reasons-your-homemade-bread-is-dense/
https://www.tasteofhome.com/article/testing-yeast/
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