Because purchasing oak barrels is so costly, many winemakers with more limited budgets opt for 'oak chips' to give their wines the flavor profile of oak aging without the enormous investment. The chips resemble mulch and are added to the vats of wine before it undergoes fermentation. They are removed when the winemaker is satisfied with the level of extraction, and can be used more than once. The cost is so minimal in comparison to barrel aging that the temptation is often too great for some winemakers. Chips are prohibited in the EU, yet the practice still goes on behind the scenes. It is not regulated by law in the United States. Though the wine does bear the characteristic flavors of oak it must be consumed young, as it does not acquire the cellaring potential gained during traditional oak aging.