Keep churns clean and well aired so they will not give up odors and flavors to the butter. After a churn has been used, rinse it with cold water and then wash it in hot water, to which washing soda has been added. Lastly, rinse with scalding water. Leave open to air when not in use, but protect from dust and dirt. =212. Drip Coffee Pots.= Drip coffee is made in a funnel or a cup-shaped device which is suspended in a coffee pot (Fig. 117). This is made either of cloth or perforated metal. The coffee is pulverized and packed into the funnel. Cold water is poured on top of the coffee and slowly filters thru it, extracting flavoring substances. The water is heated after it has filtered thru the coffee. [Illustration: FIG. 117. Drip funnel in percolator.] =213. Percolator Coffee Pots.= A coffee percolator is a device put in a coffee pot to hold the ground coffee above the water and pump some of the water to the top of the pot so that it can seep back down thru the ground coffee (Fig. 118). A perforated cup with a perforated cover holds the coffee. Thru the center of this cup passes a small tube to the top of the pot. At the bottom of the tube is a flat plate with turned-down edges or other device which supports the pipe and rests on the bottom of the pot. A small amount of water gets under this and into the pipe. The heat in the stove turns the water next the bottom to steam, and this steam, in escaping, forces the water in the pipe to the top of the pot, and raises the device slightly so that more water flows under it and into the pipe, and again steam is formed and more water forced to the top of the pot. (See Sec. 161, Suction Washers.) After being forced out of the top of the pipe, the water falls in a spray on the cover of the cup and seeps down thru the coffee back into the main part of the coffee pot. The pumping devices in percolators may differ somewhat in design, but the working principle is the same--that steam is lighter than water and can be generated in amounts which will force water up thru the central tube. [Illustration: FIG. 118. Percolator.] Coffee grounds must not be allowed to get into the small tube, for they will hinder the flow of the water. The holes in the cup and cover must be kept open. There is less waste in using finely-ground coffee than the coarsely-ground in percolators. A small tube brush is needed for cleaning percolators. The coffee must not be ground so fine that it will sift thru the perforations in the cup. CHAPTER XXX DISH-WASHERS, CANNERS AND DRYERS The dish-washers (Fig. 119) have found a place in hotels and large establishments, they are still in the experimental stage for general household use. Small machines on the market, patterned after the hotel type, are giving good results for home use. When using these machines, place the dishes in them in the manner directed and use as much water as is called for. [Illustration: FIG. 119. Dish-washer.]