Flat Biscuits

Our answer

We assume that the biscuits in this particular query are cookies rather than the American form of biscuits (which are closer to UK scones).

Generally cookies spread as the butter in the dough melts before the outside of the cookie sets firm. This can be caused by the cookie dough being too warm when it went into the oven. If the dough is warm then shape the cookies and chill them thoroughly before baking and make sure that your baking sheet isn't warm if you are transferring the chilled cookie dough from the fridge to a baking sheet. The oven temperature is also important and if your oven is running "cool" or "slow" (ie slightly below proper temperature) then this can also cause the cookies to spread. You can try checking your oven with an oven thermometer. Thermometers can be bought from cookware stores and are usually inexpensive.

Water content can sometimes also be a reason for cookies spreading. Butter typically has a water content of 14% to 18% and sometimes a small difference can affect a recipe disproportionately. Unsalted butter usually has a lower water content than salted butter, so make sure that you use unsalted butter. Some people also suggest replacing some of the butter in the dough with vegetable shortening if cookies are persistently spreading.

For rolled and cutout cookies you can try reducing the amount of baking powder or bicarbonate of soda (baking soda) which should reduce any spreading and remember that the more you re-roll the dough, the more likely they are to be mis-shapen.