How to Ice a Cake with Buttercream | Silky-Smooth Finish
Chef Alan TetreaultIn this tutorial: What You'll Need · Ice the Top · Ice the Sides · Smooth with Hot Water · Cake Combing
The secret to a crumb-free buttercream finish isn't about being careful — it's about using the right technique so your spatula never touches the cake. In this tutorial, Chef Alan Tetreault of Global Sugar Art demonstrates his preferred icing method: a quick-ice piping tip for the sides (no crumbs, guaranteed), a hot-water scraping technique for glass-smooth results, and an optional cake comb for adding texture.
What You'll Need
- Buttercream icing — if using a purchased buttercream, stir it up first to soften and smooth it
- Quick-ice tip (#789) — Wilton brand, a very large piping tip
- 18-inch piping bag (or large canvas/cloth bag) — needed to fit the #789 tip
- Offset spatula
- Metal side scraper / bench scraper (Ateco) — must be perfectly flat across the bottom edge (see notes below)
- Cake combs — Ateco triangle comb (3 different tooth sizes) or PME comb set
- Bowl of hot water — just boiled
- Paper towels or clean cloth — for wiping tools
- Turntable
The Crumb-Free Rule
The single most important principle: your spatula should never touch the cake — only the icing.
If you start in the center and push icing outward, the spatula rides on the icing you've already applied, never dragging against the cake surface. This is what keeps crumbs out of your finish.
Step 1: Ice the Top
- Put a mound of icing in the center of the cake.
- Work from the center outward with an offset spatula — push the icing to the edges.
- Don't worry about leveling it perfectly yet. Just get the icing over the top and past the edges.
Step 2: Ice the Sides with the Quick-Ice Tip
This is the game-changer for crumb-free sides:
- Fill the large bag with icing and fit it with the #789 quick-ice tip.
- Starting at the bottom of the cake, squeeze and pipe icing all the way around the tier.
- Move up and do a second pass to cover the rest of the side.
The piping tip lays down a thick, even layer of icing without any spatula contact — no crumbs get dragged up into the finish.
💡 There is no quicker or cleaner way to ice the sides of a cake. This tip alone is worth owning if you decorate cakes regularly.
Step 3: Smooth with a Hot Scraper
↪ Sides
- Dip the metal bench scraper in the bowl of hot water. Don't dry it — the heat and moisture together melt the fat in the buttercream just enough to smooth it.
- Hold the scraper flat against the board (this guarantees a perfectly vertical surface) and spin the turntable.
- Work in sections — don't try to do the whole cake in one spin. The scraper cools down quickly and picks up excess icing.
- Wipe the scraper, re-dip in hot water, and do the next section.
↪ Top
- Dip the offset spatula in hot water.
- Bring the icing from the outside edge toward the center — never push from the center outward.
- Re-dip and wipe after each pass.
💡 Don't stress the very edge. You'll be piping a border there, so the transition between top and sides doesn't need to be perfect.
↪ The key to the hot water technique
The more fat (butter or shortening) in your buttercream, the better this works. The hot water slightly melts the fat on the surface, allowing the scraper to glide and leaving a glass-smooth finish. With lower-fat icings, you'll still get a nice result, but it won't be quite as mirror-like.
Optional: Add a Combed Design
Cake combs create a grooved pattern in the buttercream:
- Heat the comb in the hot water.
- Hold it against the side of the cake.
- Spin the turntable to create the pattern.
- Work in sections — buttercream won't let you do the whole cake in one pass the way a marshmallow or boiled icing would.
Available combs: - Ateco triangle — 3 different tooth sizes on one tool - PME comb set — multiple patterns and widths
💡 Metal combs work better than plastic for this technique — they hold the heat from the hot water longer.
Choosing a Bench Scraper
Not all bench scrapers work for cake icing. The bottom edge must be perfectly flat and flush — some scrapers have a handle that's wider than the blade, which means you can't lay it flat against the board to get a truly vertical side.
Chef Alan recommends Ateco scrapers for their flat profile. Check before you buy: lay the scraper on a flat surface and make sure there's no gap under the cutting edge.
This tutorial is part of Global Sugar Art's library of free cake decorating videos by Chef Alan Tetreault. Browse all tutorials →
