The combination of different type of clay often gives negative effect

We usually do not suggest combining two or more clay tea ware of different types of material.

There are more negative effects when different types of clay are combined

There are some people who love to incorporate different types of clay ware just like the way we coordinate fashion. However, the combination of different clay materials often ruins the aftertaste of tea and frequently causes dryness in taste. This is due to the existent of different minerals in different clays. These minerals often trade off its effect by eliminating the aftertaste rather than giving a positive effect in collaboration. Normally, if different clays that follow the same firing method (such as oxidation fire or reduction fire) are used, occasionally it gives a synergy effect. For instance, a combination between Banko clay and Sado reduction clay gives far stronger aftertaste than single clay. Even so, the possibility of getting a positive outcome by the combination of different clays is very rare. Personally, I do not suggest you to combine different clays unless you are certain about the outcome after series of experiment and trial.

The clay fired with different methods, i.e., oxidation and reduction, should not be combined

The oxidation fired clay should not be combined with the reduction fired clay, because, the oxidation fired clay contains iron which is ferric (Fe3+), while the reduction fired clay contains iron which is ferrous (Fe2+). Under the circumstances, there is a collision or crush as the different state of iron cannot get along with each other. If an oxidation fired teapot is combined with a reduction fired samashi or cup, the tea would drastically lose its aftertaste; moreover, the taste would be flatter than brewing the same tea in a glass teapot.

The sequence of clay tea ware may not further improve the taste of tea

For your information, the taste of tea obtained from the following 4 brewing methods will be the same in terms of the taste and flavour.

1. Clay Teapot　→　Tea Cup made of the same clay
2. Clay Teapot　→　Glass Tea Cup
3. Clay Samashi　→　Clay Teapot made of the same clay　→　Glass Tea Cup
4. Clay Samashi　→　Clay Teapot made of the same clay　→　Clay Tea Cup made of the same clay

In fact, the taste of tea will be altered sufficiently when it comes in contact with the clay once. Therefore, brewing tea using a clay samashi, clay teapot, and then consuming using a clay tea cup will give the same effect as brewing tea in a clay teapot and drinking in a glass teacup. Under the circumstances, you may also consider the combination of porcelain/bone china teacups with clay tea ware or porcelain/bone china gaiwan with clay teacups or clay pitcher.