Foods sold under the Cottage Food Law must not require time or temperature control for safety (TCS).

Generally, you are not required to have your food tested.  Special requirements apply for canned, pickled, and fermented foods.  But if you are not sure if your food requires time and temperature control for safety, it is highly advised to have that food tested.  No one wants to make a customer sick. 

Under SB 572, DSHS is required to maintain a list of accredited testing laboratories.  The list can be found at the following link.  These labs can test your food products for pH, water activity, or both, to determine if the product requires temperature control for safety.  Texas statute uses a chart to determine whether that food is TCS or NTCS.

https://www.dshs.texas.gov/foodestablishments/cottagefood/default.aspx