In the thread on whether or not to WDT, I posted the following, which is split off to this thread on pre-infusion.

Here's a different response. I don't WDT because I usually insert filter paper at the bottom of my portafilter to reduce harmful oils. WDT disrupts that paper disc. My physician told me my cholesterol levels are good enough I don't have to do that, but I still use the filter paper to keep it low. Otherwise I would have probably used WDT. Thus my technique evolved to use either Stockfleth's or the Orphan Espresso Slapshot method. I also have good grinders, two Super Jollys, a Pharos and a Lido. Even if there are clumps they're not large and I quickly mash them down with Stockfleth's. And since I'm usually pulling shots with lever machines that tend to be more forgiving, I may work the lever to ensure the coffee puck is fully soaked before pressing the water through. Stockfleth's also works well with my Isomac Amica when I've got the dose and grind well tuned.

Once at the start of my hobby I had the good fortune to see Chris Tacy (malachi) pulling shots at a legendary San Francisco H-B cupping event. He didn't weigh doses and used Stockfleth's and said that a difference between amateurs and pros is the latter aren't concerned about wasting coffee. He would amply fill the portafilter, sweep it clear and then tamp, and he emphasized distribution. He said when he was training baristas at Stumptown they would practice their technique until they got very consistent dosing before being allowed to serve customers. So I trust that even when my pours aren't perfect they'll improve over time using Stockfleth's move. Lately I'm finding the Orphan Espresso Slapshot technique to be very effective with my commercial lever.

Note: Split from Any reason NOT to WDT? by moderator.

drgary wrote:And since I'm usually pulling shots with lever machines that tend to be more forgiving, I may work the lever to ensure the coffee puck is fully soaked before pressing the water through.

Thankyou ever so much for mentioning this - after giving this a go I haven't needed any puck prep other than a shake side to side to distribute and then tamp. Super easy naked pours each time!

drgary wrote: And since I'm usually pulling shots with lever machines that tend to be more forgiving, I may work the lever to ensure the coffee puck is fully soaked before pressing the water through.

This.
And I do the same on my Faema C85 HX pump machine as well - I activate the pump until I hear it start taking up slack, then deactivate the pump, leaving the 3-way open (the switch lets me do this, not by design but it works) I can see the puck saturate as espresso beads up on the bottom of the basket, then I turn the pump on again and pull the shot. Super forgiving.

Even my office mate can pull reasonable shots without spritzing all over the place.

I thought it ight be helpful to those of you just learning to give more detail on saturating the puck. Keep in mind this is not to dissuade using WDT, which is very effective.

My simplest use of presaturation is with my commercial lever or Lady Duchessa because both permit the lever to be locked in the down position, allowing water to flood the puck. Keep in mind this only works well when you're pretty close to target with dose and grind. I allow water to saturate until I see drops appear in the cup, which can take 20 or more seconds, but I don't just release the spring at this point. I'm also looking for distribution of the droplets, so they're evenly falling. And, I'm looking for timing of droplets. When they start falling more slowly the grinds are expanding as they absorb water. Otherwise I might promote channeling because the puck isn't fully saturated. With a fine grind I may also do a double pump known as a Fellini move to force water into the puck under pressure. I'll check the bottomless portafilter to see if coffee is beading across the filter basket. If droplets are evenly dispersed or with a fine grind if beading is present I'll then release the spring. The procedure is similar with a manual lever where instead of locking it down the lever is raised. I'm often aiming for a flow that Jim Schulman wrote about, which is to see thick, large drips of espresso start falling in the cup before they meet in a central stream. I watch the place where that stream is entering the espresso to see when it starts to lighten in color, then I pull the cup away because at this point the coffee is overextracting and will thin the shot and may introduce overextracted flavors.

It's also easy to preinfuse manually to any degree with the Breville dual boiler. You can hold down the brew button for any length of time to infuse at 1-2.5 bar (pressure is programmable), then release to go to 9 bar. You can alternatively program any preinfusion time that will run automatically at the start of brewing; the default is 7 sec. I often do something like what drgary does, watching for beading.