Overmixing cookie dough, whether it's defrosted or freshly made, can lead to undesirable results. When you overmix cookie dough, you risk developing too much gluten in the flour, which can result in tough and chewy cookies rather than soft and tender ones. However, if you need to add more dough to the first batch that you made in the freezer, you can do so without overmixing by following these steps:
Thaw the additional cookie dough: Take the extra dough out of the freezer and let it thaw in the refrigerator until it's soft enough to work with but not completely melted.
Break the dough into smaller pieces: To incorporate it into the existing batch without overmixing, start by breaking the defrosted dough into smaller pieces. This will make it easier to distribute throughout the existing dough.
Gently fold in the dough: Add the smaller pieces of defrosted dough to the original batch. Use a spatula or your hands to gently fold and incorporate the dough into the existing batch. Be careful not to overmix or knead the dough excessively.
Chill the dough: Once the additional dough is evenly distributed, consider chilling the combined dough in the refrigerator for a short time. This will help firm up the dough before baking and make it easier to work with.
Adjust baking soda: Since you mentioned adding too much baking soda in the first batch, it's essential to address this issue. If you want to adjust the leavening agent, consider using a different batch of dough without the excessive baking soda or lessen the impact by adding a bit more flour or other ingredients.
By following these steps and being mindful of not overmixing, you should be able to incorporate the extra cookie dough into the first batch without negatively affecting the texture of your cookies. Remember, gentle folding and minimal mixing are the keys to achieving soft and delicious cookies.