I have been told on several occasions that coffee made in a cafetiere/plunger should never be made with boiling water as this can "scald" the coffee and lead to a slightly unpleasant bitter taste in the coffee...do folks here worry about this when making their brews? I don't usually use a cafetiere (prefer my espresso maker, or a stove-top percolator at a push) and am wondering how to avoid scalding the coffee in these, or if it really matters that much?.....