The Brisker Rav was known for his great exactness when it came to Mitzvot, such as making matzot or picking a lulav and etrog. He was equally careful to avoid Averot as well. And he was extremely careful with the l aws of Terumot and Ma’asrot in Israel. Fruit and vegetables grown and Israel need to be tithed . There are various hashgachot/ supervising agencies that take care of that, but the Brisker Rav ( and many others ) were careful to retithe in their own homes , because they felt that mistakes could arise, and things could go wrong with anything done in a mass fashion. (They are even great Rabbi s who retithe the soda in Israel , because it has fruit juice in it. When we were in Israel visiting Rav Binyamin Finkel , known as Binyamin Hasadik, he gave us soda to drink . We noticed that there was a letter Mem on it , and when we ask ed about it, they told us it stood for Ma’aser because he had retithed the bottle . He was careful to say that it was really kosher and this was just an added humra/stringency ) If you have 100 apples, you could take one from the 100 as teruma , and 10 apples from the 100 is maaser. But there is a law that you can’t take from one crop on another, or different fruits from different trees or batches- just like when you’re taking challah , you have to know which batch it is from. The Brisker Rav, in his chumrot , was always concerned that if there were 100 apples, they might have come from different fields or different crops. So he would tithe each fruit separately. He would cut each and every apple , and although it was a little bit more difficult this way, he had to take care of it properly. It happen ed once that a group of about 30 orphans came to visit his home. They were surviv ors from World War II and learning in a Mossad in Sanhedria. The Rav wanted to serve them oranges , but we said , he would always cut out a piece from each fruit. He was worried that it might not be the proper respect for these orphans to get an orange with a cut in it. So he came up with an idea - He would cut off the top of each orange and put a sugar cube in each one. In that way, it would look like a decorative item, a pretty orange with a sugar cube on top! That is how far he went in his thinking, to make sure that there w ouldn’t be even the slightest insult to an orphan, but at the same time keep ing the Hala cha . This ingenious idea that he came up with show ed the level of his sensitivity , which is mind boggling. Have a wonderful day.