琼脂又名洋菜,南货店中,均有出售,是极普通的辅佐食品之一,夏天也可以做凉粉。牠的简便制法,大致如下.琼脂原料是一种海藻,就是石花菜,琼脂是由生石花菜制成。战前市上南货店出售的货,大多是日本货。日本人制造琼脂,纯用土法。先将生石花菜洗净,加以漂白,放入一大铁锅内,加水五十倍,这就是说,譬如用生石花菜十斤,应该加水五百斤。加水之后,乃加热到沸腾,同时不时用棒混搅。这样连续烧沸约五六小时,然后用硫酸或醋加入锅内,这可以帮助生石花菜加速消化。至于硫酸或醋和生石花菜之比例,是一和一千之比例,或十和 Agar also known as Agar, South store, are sold, is one of the most common food supplement, summer can also do jelly. Its simple system of law, roughly as follows.A agar raw material is a seaweed, is the cauliflower, agar is made of raw stone cauliflower. Pre-war shops on the South to sell goods, mostly Japanese goods. Japanese made agar, pure soil method. First, raw stone cauliflower washed, bleached, into a large iron pot, add water fifty times, which means that, for example, with ten pounds of raw stone cauliflower, water should be five hundred pounds. After adding water, it is heated to boiling, while mixing with a stick from time to time. This continuous boiling about five or six hours, then add sulfuric acid or vinegar into the pot, which can help accelerate the digestion of raw stone cauliflower. As for the ratio of sulfuric acid or vinegar to raw seaweed, the ratio is one to one thousand, or ten