Since I've been home roasting, I've always used the Barista Hustle water recipe for brewing, however last week I ran out of distilled water and had to use tap water.

My morning brewing routine stayed exactly the same, but with using tap water, my brew time increased by almost 50%. The drawdown was incredibly slow. I initially thought I had messed up my grind size, but after I was able to stop at the store for distilled water and do a side-by-side with only the water being the dependent variable, it confirmed my initial results.

50% increase in brew time seems pretty drastic, but after repeated side by side experiments, I can't ignore it. Has anyone else had such dramatic differences in drawdown times using tap water versus another Third Wave water? I am shocked.

As a rule, no, I get similar draw down times whether I use our tap water or using remineralized distilled water. But I do have an anecdote that might be relevant to your situation.

I usually rinse my filters with tap water before brewing. A few years ago, in the wake of a hurricane, I noticed that draw down times got much longer. I switched to rinsing the filters with filtered water from the fridge and the draw down times were back to normal. I think the culprit in my case was churned up fine sediment in our reservoirs due to all the storm activity. Maybe your tap water also has a lot of suspended fine sediment in it that is clogging your filters?

I was thinking the same thing, I can't imagine mineral content making a significant difference, but sediment is another story. Some filters are more prone to getting clogged than others (chemex for example clogs easily). If you think your tap water might otherwise be fine for coffee brewing, an inexpensive filter like a Brita will remove sediment and chlorine while leaving minerals mostly alone.

tyfabes wrote:Since I've been home roasting, I've always used the Barista Hustle water recipe for brewing, however last week I ran out of distilled water and had to use tap water.

My morning brewing routine stayed exactly the same, but with using tap water, my brew time increased by almost 50%. The drawdown was incredibly slow. I initially thought I had messed up my grind size, but after I was able to stop at the store for distilled water and do a side-by-side with only the water being the dependent variable, it confirmed my initial results.

50% increase in brew time seems pretty drastic, but after repeated side by side experiments, I can't ignore it. Has anyone else had such dramatic differences in drawdown times using tap water versus another Third Wave water? I am shocked.

The beans themselves probably have one of the most noticeable influence over draw downs. For me, the difference can be 1 minute of extra draw down for some beans taking a pour over from 2:30 to 3:30.

Also, agitation during pouring regardless if intended or not. Consistently I find that a more aggressive faster pour actually equates to a longer overall brew. Meaning if I pour aggressive and finish by 1:15 it might take two minutes to draw down. Where as if I pour gently and finish at 1:30 or 1:45 draw down is much shorter as is the overall brew time.

FWIW, as reported in the 2011 SCAA water quality handbook, work back in the 50' or 60's at the coffee brewing center found that very high bicarbonate was associated with slower flow through a coffee bed. At 400 ppm NaHCO3 vs deionized, they saw a 70% increase in brew time, but not at 100 ppm (which is closer to what you probably have in Milwaukee tap.) Interestingly, when comparing softened water in Dallas and Los Angeles vs unsoftened water, they did see slower flow in softened vs unsoftened (appx 50% increase in brew time for softened LA water.)

Tyler, Is your tap water softened?

Thanks for all of the insights!

Yes, my water is softened, but I've also been using filtered water from the fridge. Sediment could certainly be a factor, but the filter was changed just under a month ago.